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| INTRODUCTION
TO LUTJANID LARVAE | | The
snappers are a prominent family of predatory fishes found in all tropical waters
and are often associated with reef or mangrove habitats. The deeper-water species,
in particular, are an important component of fisheries in the Caribbean and the
Gulf of Mexico. There are numerous snapper species in the region and most of them
can be found on coral reefs. The shallow-water snappers are almost all members
of the large genus Lutjanus spp.
The one exception, the yellowtail snapper Ocyurus
chrysurus, falls well within the Lutjanus
spp. clade in phylogenetic studies. There are four additional deep-water
lutjanid genera, three with only a single Caribbean representative. |
| | | Larval
snappers exhibit the standard percoid characters shared to some degree by many
other families: a wide body, large round eye, large terminal mouth, stout spines
in the fins and a short anal fin with three spines. Lutjanid larvae are distinctive
in having a large non-serrated spine at the angle of the preopercle. Fin-ray counts
broadly overlap with two other common reef-fish families: the seabasses and groupers
(Serranidae) and the grunts
(Haemulidae). Separating
snappers from serranids is not always easy and useful characters are discussed
in detail below. Grunts are easy to distinguish since they have narrower bodies,
short non-serrated dorsal-fin spines, and they are typically much smaller at each
stage of development. | | |
| Regional
Species: There are at least ten
Lutjanus spp. in the region. The shallow-water species show a curious
pattern of pairs of similar species. DNA sequence analyses reveal that some of
these pairs are close relatives, but some are not. There is a pair of small snappers
with a lateral spot that are closely-related: the mahogany snapper
L. mahogoni and the lane snapper
L. synagris. This pair is distinct in having only twelve dorsal-fin
soft rays (D-X,12), while the remaining species in the genus have fourteen (D-X,14).
The mutton snapper L. analis
has a similar lateral spot but is more distantly related. | | |
|
A separate group is made up of snappers without
a lateral spot and with bars and/or a stripe
through the eye. The schoolmaster snapper
L.
apodus and the dog snapper L.
jocu are similar and differ primarily
in lateral line scale counts and some markings.
The gray snapper L.
griseus and the cubera snapper L.
cyanopterus make up another pair that
appear similar as adults; small cubera snappers
are almost identical to gray snappers but
are typically distinguished by growing to
a much larger size, up to 125 pounds and over
four feet in length. Interestingly, my mtDNA
sequence analyses suggest that these two species
are not closely-related; gray snappers are
part of the schoolmaster/dog clade while the
cubera snapper is well out on its own branch
in the phylogenetic tree. |
| |
| Three
Lutjanus spp. are predominantly
deep-water denizens, although juveniles occasionally
occur in shallower reef areas: the blackfin
snapper L.
buccanella, the silk snapper L.
vivanus, and the red snapper, L.
campechanus. The southern red snapper,
L. purpureus,
has recently been shown to have identical
DNA sequences at multiple loci to the red
snapper, L. campechanus,
indicating that it represents the southern
population of the red snapper (Gomes et al.
2007). L. campechanus
from the Gulf of Mexico typically have nine
anal fin spines, but outside of the Gulf they
likely share the modal eight anal fin rays
of the other species in the genus. These deep-water
Lutjanus spp. have typical fin
ray counts (D-X,14 Pect-17) and fall within
the same clade as the lateral-spot snappers.
Interestingly, they also have lateral spots,
at least to some degree, as juveniles. |
| |
| There are four other lutjanid
genera with a single Caribbean species each. The common yellowtail snapper Ocyurus
chrysurus (D-X,13 A-III,9 Pect-15-16) forages in open water and thus has
a more streamlined body form than other snappers. As a result, it has been placed
in its own genus. Nevertheless, in phylogenetic studies it falls well within the
Lutjanus spp. clade and
probably should be included in that genus. Three deep-water snapper genera
have a single regional species each and comprise Apsilus
dentatus (D-X,10 Pect-15-16), Etelis oculatus
(D-X,11 Pect-15-16), and Rhomboplites aurorubens
(D-XII,11 Pect-17-18). The remaining deep-water snapper genus has three species,
all with the same fin-ray counts of D-X,11 Pect-15-16: Pristipomoides
aquilonaris, P. freemani, and P.
macrophthalmus. | | |
Diagnostic
Characters for Lutjanid Larvae:
|
| Early-stage
Larvae: Less-developed lutjanid larvae
occasionally appear in collections made over
the reef. They conform to many of the basic
features of percoid larvae: large head, large
round eye, large mouth with a prominent jaw
angle, prominent preopercular spines, a wide
body, continuous dorsal fins with stout spines,
a short anal fin with three stout spines,
and elongated and stout pelvic-fin spines.
Features more specific to lutjanids, especially
Lutjanus spp., are the moderately-serrated
dorsal and pelvic-fin spines (these spines
and the anal-fin spines often have anterior
serrations as well), the first pelvic-fin
ray longer than the spine, a non-serrated
spine at the angle of the preopercle, and,
most distinctive, a post-cleithral spine. |
| |
| A number of families have similar-appearing
early-stage larvae, fortunately few occur in the Atlantic. The most likely confusion
in the region is with serranid
larvae, especially since there is some overlap in fin-ray counts between Caribbean
lutjanid and serranid species. In general, serranid species in the region have
only seven (serranines)
or nine or ten (epinephelines)
anal-fin soft rays, and most lutjanids have eight, but this is a fine point for
distinguishing larvae. | | |
| The most difficult to distinguish
at early stages are the D-X,12 snappers and the Serranus
spp. (the epinepheline
serranids have more dorsal-fin soft rays). In this case, the early-stage larval
snappers have mildly-serrated fin-ray spines and the prominent non-serrated preopercular
spine while the Serranus
spp. have smooth spines and no prominent preopercular spine. | | |
| There is a slight fin-ray-count
difference between the D-X,14 snappers and the epinepheline
serranids. Virtually all of the Caribbean epinephelines have either eight, nine,
or eleven dorsal-fin spines and most have more than 14 dorsal-fin soft rays and
nine or ten anal-fin soft rays: lutjanids have ten dorsal-fin spines (one with
12), 14 and fewer dorsal-fin soft rays, and eight anal-fin soft rays (two with
nine). In addition, the few overlapping epinephalines have 18 or more pectoral-fin
rays (vs. 16-17 in the lutjanids). | | |
| The pretransitional larval epinephelines
have markedly-serrated and extended dorsal and pelvic-fin spines, while the snappers
do not. In addition, the second dorsal-fin spine is usually markedly longer than
the third vs. slightly longer or similar in length in the late-stage larval snappers
(this distinction may not apply to some deep-water snapper genera). The snapper
preopercular spine is notably non-serrated, while that of the epinephelines
is serrated, but that is not always obvious on initial inspection. In addition,
lutjanids have the first pelvic-fin soft ray longer than the spine vs. distinctly
shorter in epinephelines. Finally, there is a characteristic post-cleithral spine
in lutjanid larvae that is not present in the serranids. (Note: special thanks to Jeff
Leis and his books). | | |
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| Lutjanus (synagris)
larva | | 5.1 mm SL | Dorsal
formula X,12
note post-cleithral spine and serrated
pelvic-fin spines
(vs. Serranus spp.),
and first pelvic-fin ray longer than spine
(vs. the epinepheline
groupers ) | | San Blas, Panama, SB86-1103 |
|  | | |
 | | |  |
| Lutjanus
(griseus) larva | | 6.0 mm SL |
note post-cleithral spine, melanophores at
base
of dorsal fin spine membranes | | San
Blas, Panama, SB81-040 | |  |
| |  |
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| |
| Late-Stage
Larvae: Lutjanid larvae in general share a number of basic features, most
particularly a long non-serrated preopercular spine. The spine decreases in length
during transition and disappears in juveniles. There are also smaller spines lining
the lower and posterior margins of the preopercle that similarly decrease in prominence
during transition. Pretransitional larvae can show a row of fine serrations along
the supraorbital bony ridge (preopercular spine and supraorbital serrations visible
at the top of the photograph below of a 12.2 mm SL grey snapper larva, L.
griseus). | |
 |
| | |
Marking patterns on the late larvae of most
snappers can be quite similar, and comprise variations of the basic theme of mostly
dorsal-facing melanophores. This suggests that melanophores function as shielding,
protecting vulnerable organs from sunlight. Indeed, it would be plausible to infer
from this pattern that snapper larvae are living near the ocean surface during
the day. Melanophores shield the brain and spinal column by running along the
top of the brain itself, at the surface over the braincase, along the dorsal fins,
and along the dorsal caudal peduncle. Internal melanophores line the dorsal aspect
of the vertebral column, often with an additional short row beside or below the
column near the tail. Melanophores line the dorsal surface of the swim-bladder
and peritoneum (overlying the abdominal organs). In addition, the inner-facing
cleithrum (the lower rear wall of the gill cavity) is pigmented and overlies thoracic
structures. Additional melanophores present on most species' larvae include a
few deep at the lateral midline on the caudal peduncle, a ventral midline caudal
peduncle row (often just one or two large melanophores), a few at the very base
of the lower caudal-fin segmented rays, and along the base of the membranes of
the anal-fin rays. A distinctive deep melanophore is present from the early stages
under the pterygiophores of the last anal-fin rays (an additional "repeat" melanophore
is sometimes present on the next segment anteriorly). The internal vertebral melanophores
can be seen on the transitional larval yellowtail snapper photograph below (Ocyurus
chrysurus, 17.0 mm SL) and beginning in the early larva of L.
griseus, photographed above). |
| 
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| |
| | Ocyurus chrysurus
(Lutjanus chrysurus) |
| |
| | Diagnosis:
Modal fin-ray counts of D-X,13 A-III,9 indicate Ocyurus
chrysurus. (DNA) | |
Analogues:
Pretransitional larvae (mostly-unmarked stage, usually from 12-17 mm SL)
can be separated from the other regional snappers by the dorsal-fin-ray count.
Additional useful distinguishing features include the dorsal and anal-fin spines
relatively slender (shared with L.
cyanopterus and L. analis),
the second to fifth dorsal-fin spines about the same length, the anal-fin spines
without prominent anterior serrations (vs. L.
griseus, L. apodus
and L. jocu), the third anal-fin
spine usually longer than the second (the tip of the third almost always extending
farther back than the tip of the second when folded down), no lateral spot or
bars, and a thin stripe of small surface melanophores extending forward along
the lateral midline from the center of the caudal peduncle. The occasional individual
has at most one or two melanophores at the base of the lowest of the upper caudal
fin segmented rays (vs. several in L.
synagris and L. mahogoni).
Transitional O. chrysurus larvae develop a mostly-uniform scattering
of small melanophores on the body with no lateral spot or bars, distinguishing
them from most other regional snappers. Early in transition, the row of fine surface
melanophores extending forward from the caudal peduncle along the lateral midline
distinguishes the species from other snappers. Later in transition and in juveniles,
a pale midline lateral stripe is diagnostic (yellow in live specimens). |
| | Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Mostly
unmarked stage, usually from 12-17 mm SL:
Body: Pretransitional
larvae develop a row of melanophores on the side of the body near the base of
the dorsal fin. The row starts as a series of short angled lines along the anterior
aspect of each pterygiophore below the soft dorsal fin, then small melanophores
fill in the row. The row extends forward on the body below the spinous portion
of the fin, first as a few spots beneath the seventh and eighth spines and the
ninth and tenth spines, and then filling in, up to the level of the third dorsal-fin
spine. The two rows on each side of the body merge into a band of melanophores
lining the dorsal midline of the caudal peduncle extending to the start of the
procurrent caudal-fin rays. A similar band develops along the ventral midline
of the caudal peduncle extending forward and ending just before a single large
melanophore underlying the pterygiophores of the last anal-fin rays. There are
a few deep melanophores at the end of the lateral midline of the caudal peduncle
and a fine speckling of small melanophores around the central caudal peduncle
extending forward in a thin line along the lateral midline. There is a single
large melanophore underlying the pterygiophores of the last anal-fin rays. A series
of short angled lines of small melanophores develops along the anterior aspect
of the anal-fin pterygiophores, starting between the second and fifth fin rays.
Head: Melanophores on the head consist of dense patches overlying the
brain and on the surface braincase. There are small melanophores around the tip
of the upper jaw, along the adjacent snout, and along the tip of the lower jaw.
The opercular area is covered in iridescence extending down to the pelvic-fin
insertion. The inner cleithral surface of the gill cavity is speckled with large
melanophores and there are internal melanophores lining the dorsal aspect of the
swim bladder and peritoneum extending down to the vent and overlain by a silvery
camouflage layer.
Fin Spines: The dorsal and anal fin spines are relatively
slender, without prominent internal reticulations. The second to fifth dorsal-fin
spines are about the same length (the second sometimes shorter). The anal fin
spines do not show anterior serrations. The third anal fin spine is usually longer
than the second (the tip of the third almost always extending farther back than
the tip of the second when folded down).
Fins: Melanophores are present
along most of the length of the membrane just behind the second dorsal-fin spine
and then near the outer edges of most of the subsequent membranes of the spinous
portion of the dorsal fin. There are a few melanophores between the bases of the
lower central caudal-fin segmented rays and the occasional individual has, at
most, one or two melanophores at the base of the lowest of the upper caudal-fin
segmented rays. A row of melanophores develops along the anal-fin base, one at
the base of each anal-fin-ray membrane, often including the membrane behind the
third-spine. Some individuals have melanophores on the distal half of the two
longest pelvic-fin rays. | |
| Transitional
stage:
Transitional larvae develop a relatively uniform scattering of tiny
melanophores on the body, | | |
|
| Ocyurus chrysurus
larva | | 16.7 mm SL | | San
Blas, Panama, SB81-024 | |  |
| | |
| |
|
| Distinguishing
the larvae of the numerous Lutjanus spp. in the region can be difficult
since many share the basic body form as well as most fin-ray counts. Fortunately,
two common species, both with a lateral spot, do separate out by meristics:
L. mahogoni and L. synagris
have only twelve vs. the typical 14 dorsal-fin soft rays for the genus. Beyond
this, distinctions can be difficult, even for juveniles, since transitional and
juvenile snappers in general can share many of the basic markings that later distinguish
species (such as lateral spots, incipient bar patterns, and eye stripes). This
pattern of earlier stages sharing characters that later diverge is commonly seen
in reef fishes. | | |
| My DNA sequencing has clarified
the identification of the late-stage larvae of all but one of the shallow-water
14-dorsal-rayed species (except
L. jocu). The deep-water species,
L. buccanella, L. campechanus
and L. vivanus, await more
sampling for a complete treatment. Unfortunately, larvae of the Lutjanus spp.
are very similar and some of the more important characters that distinguish species
can change rapidly during transition. This requires that larvae be compared with
others at the same stage of development. In the analogues section
for each species below, I try to indicate which features are important at which
stage. Marking patterns in this group are particularly labile, but are still valuable
for identifications. Relative dorsal-fin spine lengths can be important characters,
but also change during transition. It is likely that some early pretransitional
snapper larvae will require DNA sequencing for species identification. |
| |
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| | Diagnosis:
Modal fin-ray counts of D-X,12 A-III,8 indicate Lutjanus mahogoni
or L. synagris. Juveniles
with the lateral line running through the middle of the lateral spot indicate
L. mahogoni. (DNA) | |
| Analogues:
Pretransitional larvae (mostly-unmarked stage, usually from 17-21 mm SL)
can be separated from the 14-dorsal-rayed snappers by the dorsal-fin-ray count,
as well as by having melanophores at the bases of the upper as well as the lower
caudal-fin segmented rays. The dorsal and anal-fin spines of larval L. mahogoni
are also stout (compared to relatively slender in L.
analis, L. cyanopterus,
and Ocyurus chrysurus). L.
mahogoni larvae at this stage also do not have distinct anterior serrations
persisting on the anal fin spines (occasional individuals do have a few remnant
serrations)(vs. L. griseus,
L. apodus and L.
jocu), and the second anal-fin spine is only slightly longer than the
third and their tips are usually closely-approximated when the fin is down. Almost
all pretransitional L. mahogoni captured over the reef already show the
lateral spot, unlike the spotted 14-dorsal-rayed species. The two 12-dorsal-rayed
snappers are best distinguished by the relative lengths of the second and third
dorsal-fin spines: in L. mahogoni the second dorsal-fin spine is longer
than the third spine with the tip often overlapping the tip of the third vs. shorter
than the third spine in L. synagris.
Transitional larvae of L. mahogoni always have a lateral spot,
then they subsequently develop bars (vs. bars, then a spot on L.
analis). The spot is large and expands the bar, unlike the spotted 14-dorsal-rayed
snappers. There is usually a difference in the spot location between the two 12-rayed
species (although some individuals do overlap): the lateral line runs through
the middle of the spot in L. mahogoni and through the lower third of the
spot in L. synagris. In
addition, the second dorsal-fin spine is longer than the third (or about equal)
for L. mahogoni vs. shorter in L.
synagris and this difference persists in juveniles up to 25 mm SL.
Some
transitional larvae and early recruits of L.
analis with a lateral spot can look remarkably similar to L. mahogoni
(not an issue for the many transitional L.
analis who have not developed the lateral spot and have only the backward-sloping
bars). Other than the soft dorsal fin-ray counts and the stoutness of the fin
spines (14 and relatively slender in L.
analis), the species can be separated by some marking differences: the
lateral spot runs through the middle of the lateral spot in L. mahogoni
(vs. through the lower third) and the spot is larger in L. mahogoni, expanding
the bar from which it develops, while in L.
analis the spot is only as wide as the bar from which it forms. In addition,
the bars on the body of transitional L. mahogoni slant backward less than
those of L. analis. In addition,
most transitional recruits of L. mahogoni and L.
synagris develop dark edging to the dorsal-fin membranes above the lateral
spot, while the markings are uniform on those dorsal-fin membranes in L.
analis.
Juvenile L. mahogoni and L.
synagris can be distinguished by the lateral-spot location and the relative
dorsal-spine-length characters. They both have yellow stripes as juveniles, although
the stripes become thinner and less conspicuous on juvenile L. mahogoni
and more prominent on later juvenile L.
synagris. Juvenile L. analis
have their lateral spot higher on the body (lateral line through the lower third
of the spot). Larval L. mahogoni often have
an upturned preopercular spine, but this character is not consistent. The preopercular
outline is similar in the two species, with L. mahogoni
larvae and juveniles not showing the notch pattern that occurs later. The relative
dorsal-spine lengths and spot position persist in juveniles up to 25 mm SL. |
| | Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Mostly
unmarked stage, usually from 17-21 mm SL:
Body: Pretransitional
larvae develop a row of melanophores on the side of the body near the base of
the dorsal fin. The row starts as small melanophores, often lined up along the
anterior aspect of the pterygiophores below the soft dorsal fin. The row fills
in under the soft dorsal fin and extends forward just below the spinous portion
of the fin, first as a few spots beneath the third to fifth spines and the seventh
to ninth, and then filling in up to the level of the third dorsal-fin spine. The
two rows on each side of the dorsal fin merge into a line of melanophores lining
the dorsal midline of the caudal peduncle (usually made up of a short row of deeper
and larger larval melanophores overlain by a band of smaller melanophores). A
similar line develops along the ventral midline of the caudal peduncle extending
forward and ending just before a single large melanophore underlying the pterygiophores
of the last anal-fin rays. There are a few deep melanophores at the end of the
lateral midline of the caudal peduncle and a fine speckling of small melanophores
around the central caudal peduncle.
Head: Melanophores on the head
consist of dense patches overlying the brain and on the surface braincase. There
are small melanophores around the tips of the upper and lower jaws. The opercular
area is covered in iridescence extending down to the pelvic-fin insertion. The
inner cleithral surface of the gill cavity is speckled with large melanophores
and there are internal melanophores lining the dorsal aspect of the swim bladder
and peritoneum extending down to the vent and overlain by a silvery camouflage
layer.
Fin Spines: The dorsal and anal fin spines are relatively stout,
usually with some internal reticulations. The tip of the second dorsal-fin spine
often curves slightly upward (the preopercular spine often curves slightly upward
as well). The second dorsal-fin spine is usually longer than the third and typically
the tip overlaps or extends beyond the tip of the third. The dorsal-fin spines
then become progressively and evenly shorter such that the profile of the spinous
tips forms a straight downward-sloping line. The anal-fin spines do not show anterior
serrations (a rare individual has small remnant serrations). The second anal-fin
spine is longer than the third, but the tips are closely-approximated or the third
extends slightly farther back than the tip of the second when folded down.
Fins:
Melanophores are prominent along most of the length of the membrane just behind
the second dorsal-fin spine and are concentrated on the membrane tag extending
beyond the spine. Smaller melanophores speckle the outer third of all of the subsequent
membranes of the spinous portion of the dorsal fin. On the caudal fin there are
a few small melanophores at the base of some of the upper as well as most of the
lower segmented rays. A row of melanophores develops along the anal-fin base,
one at the base of each anal-fin-ray membrane, often including the membrane behind
the third-spine. | |
O | |
|
|
| Lutjanus mahogoni
larva | | 16.7 mm SL | | San
Blas, Panama, SB86 | | |
| | |
| | |
|
| | Diagnosis:
Modal fin-ray counts of D-X,12 A-III,8 indicate Lutjanus synagris
or L. mahogoni. Juveniles
with the lateral line running through the lower third of the lateral spot indicate
L. synagris. (DNA) | |
Analogues:
Pretransitional larvae (mostly-unmarked stage, usually from 13-19 mm SL)
can be separated from the 14-dorsal-rayed snappers by the dorsal-fin-ray count,
as well as having melanophores at the bases of the upper as well as the lower
caudal-fin segmented rays. L. synagris larvae at this stage also do not
have distinct anterior serrations persisting on the anal fin spines (occasional
individuals do have a few remnant serrations) and the second anal-fin spine is
only slightly longer than the third and their tips are closely-approximated when
the fin is down. Almost all pretransitional L. synagris captured over the
reef already show the lateral spot, unlike the spotted 14-dorsal-rayed species.
The two 12-dorsal-rayed snappers are best distinguished by the relative lengths
of the second and third dorsal-fin spines: in L. synagris the second dorsal-fin
spine is shorter than the third spine vs. longer (pretransitional larvae) to about
equal (late in transition) to the third spine in L.
mahogoni.
Transitional larvae of L. synagris always
have a lateral spot, then they subsequently develop bars (vs. bars, then a spot
on L. analis). The spot is
large and expands the bar, unlike the spotted 14-dorsal-rayed snappers. There
is usually a difference in the spot location between the two 12-rayed species
(although some individuals do overlap): the lateral line runs through the lower
third of the spot in L. synagris and through the middle of the spot in
L. mahogoni. In addition,
the second dorsal-fin spine shorter than the third for L. synagris (vs.
longer or equal in L. mahogoni)
difference persists in juveniles up to 25 mm SL.
Some transitional
larvae and early recruits of L.
analis with a lateral spot can look remarkably similar to L. synagris
(not an issue for the many transitional L.
analis who have not developed the lateral spot and have only the backward-sloping
bars). Other than the soft dorsal fin-ray counts (14 in L.
analis), the species can be separated by some subtle marking differences:
the location of the lateral spot is the same in the two species (lateral line
running through the lower third of the spot), but the spot is larger in L.
synagris, expanding the bar from which it develops, while in L.
analis the spot is only as wide as the bar from which it forms. In addition,
the bars on the body of transitional L. synagris slant backward less than
those of L. analis. Nevertheless,
the most consistent difference is the angle of the bar anterior to the lateral
spot: in L. synagris the bar brackets the spot, i.e. curves forward just
below the dorsal fin and then slants backwards below the level of the spot, while
in L. analis the bar slopes
evenly down to the rear from the base of the dorsal fin across the body. In addition,
most L. synagris and L. mahogoni
have dark edging to the dorsal-fin membranes above the lateral spot, while the
markings are uniform on those dorsal-fin membranes in L.
analis. On new recruits, the iridescent stripes along the lower side of
the body characteristic of L. synagris are absent in L.
analis.
The lateral-spot location and the relative dorsal-spine-length
characters separate juvenile L. synagris and L.
mahogoni. They both have yellow stripes as juveniles, although the stripes
become prominent on later juvenile L. synagris and thinner and less conspicuous
on juvenile L. mahogoni.
Juvenile L. analis can have
the lateral spot in the same location as L. synagris and can also have
yellow stripes on the side of the body: ultimately, the species can be separated
by the soft-dorsal-fin-ray count. | |
| | Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Mostly
unmarked stage, usually from 13-19 mm SL:
Body: Pretransitional
larvae develop a row of melanophores on the body near the base of the dorsal fin,
first along the pterygiophores supporting the soft dorsal fin (starting between
the second and sixth rays) and then extending along the spinous portion as a few
spots between the seventh and eighth spines and the ninth and tenth spines. As
development continues, the row of melanophores below the dorsal fin fills-in and
extends forward to the level of the third spine (the base of the last three soft
rays remains unmarked well into transition). Melanophores line the dorsal and
ventral midlines of the caudal peduncle and there are a few scattered surface
melanophores above and below the midline. There are some deep melanophores visible
along the posterior lateral midline of the caudal peduncle. Forward of the ventral
midline row there is a a large melanophore underlying the pterygiophores of the
last anal-fin rays.
Head: Melanophores on the head consist of dense
patches overlying the brain and on the surface braincase. There are small melanophores
around the tips of the upper and lower jaws. The opercular area is covered in
iridescence extending down to the pelvic-fin insertion. The inner cleithral surface
of the gill cavity is speckled with large melanophores and there are internal
melanophores lining the dorsal aspect of the swim bladder and peritoneum extending
down to the vent and overlain by a silvery camouflage layer.
Fin Spines:
The dorsal and anal fin spines are relatively stout, usually with some internal
reticulations. The anal-fin spines do not show anterior serrations. The second
anal-fin spine is usually longer than the third (the tip of the second almost
always lining up with or extending farther back than the tip of the third when
folded down).
Fins: Small melanophores speckle the distal two-thrids
of the dorsal-fin-spine membranes. On the caudal fin there are a few small melanophores
at the base of some of the upper as well as most of the lower segmented rays.
A row of melanophores develops along the anal-fin base, one at the base of each
anal-fin-ray membrane, often including the membrane behind the third-spine.
|
| |
Transitional larvae develop bars along the side of the body that slant slightly
backwards with a prominent lateral spot under the anterior soft dorsal fin. The
lateral line runs through the lower third of the spot. Later, iridescent bars
form at each side of the lateral spot, bracketing the black spot up to the base
of the dorsal fin. The dark bar just anterior to the spot curves forward following
the bracket before continuing down slanting to the rear. An additional set of
thin iridescent stripes develops along the lower side alternating with thin stripes
of melanophores (in life the pale stripes are yellow). The dorsal-fin membranes
above the lateral spot typically show a rim of dark edging in new recruits. On
the head the snout patch of melanophores meets with the dorsal head markings,
the lower jaw patch extends down most of the way along the lower jaw and melanophores
fill in between the eye and the jaws in a loose stripe mostly below the line from
the center of the eye to the tip of the snout. | | |
|
| Lutjanus synagris
larva | | 17.7 mm SL | | note
internal melanophores over vertebrae | | San
Blas, Panama, SB81-039 | |  |
| Lutjanus synagris
transitional larva | | 16.4 mm SL |
| note incipient bar pattern | |
| San Blas, Panama, SB81-047 | |  |
| Lutjanus synagris
transitional recruit | | 17.7 mm SL |
lightly marked, note faint bars and stripes
and
iridescent bars bracketing the spot | | St.
Thomas, USVI, ST506 | |  | | |  |
| |  |
| | |
| | |
14-rayed Lutjanus spp.,
the L. griseus-apodus-jocu
clade | | | |
| | |
|
| | Diagnosis:
Modal fin-ray counts of D-X,14 A-III,8 are shared among most of the regional
Lutjanus spp., including L.
analis, L. apodus,
L. cyanopterus, L.
griseus, L. jocu and the
deep-water snappers L. buccanella,
L. campechanus and L.
vivanus. Juvenile L. griseus have
a prominent dark stripe through the eye, a dark striped body and no lateral spot.
(DNA) | |
Analogues:
Pretransitional larvae (mostly-unmarked stage, usually from 10-13 mm SL)
are separated from some other Lutjanus spp. by having distinct serrations
persisting on the anterior profile of the anal and dorsal-fin spines (but shared
by L. apodus and L.
jocu). The L. griseus larval type is distinguished from the L.
apodus and L. jocu types
at this stage by having the spinous-dorsal-fin melanophores mostly on the proximal
half of the membranes and at the dorsal midline around the insertion of the spines
(vs. melanophores concentrated on the distal portion of the membranes and sparing
the dorsal midline at the base of most of the dorsal spines). Additional features
separating L. griseus from L.
apodus are a uniform melanophore scattering on the lower caudal peduncle
(vs. concentrating as a bar at the posterior half), more melanophores on the tip
of the upper than lower jaws, and unmarked pelvic fins (at most a single melanophore).
Transitional L. griseus larvae tend
to have a relatively uniform scattering of melanophores
on the body with no lateral spot, distinguishing
them from the other spotted or barred species (L.
mahogoni, L.
synagris, L.
analis, L.
apodus, and the deep-water snappers). Furthermore,
transitional L. griseus usually retain anterior
serrations on the anal-fin spines separating them
from most snappers (except some L.
apodus and L.
jocu). Some transitional L. griseus
may have indistinct bars, but these are typically
limited to the upper half of the body (vs. obvious
full-body bars in larval L.
apodus and L.
analis). Another difference on transitional
individuals with pigmented caudal peduncles is that
the peduncle adjacent to the base of the caudal
fin can be abruptly light in L. griseus and
uniformly speckled to the base in the other species.
Especially on early-transitional stages, L.
griseus have a lightly-marked lower jaw and
head below the level of the eye (vs. heavily spotted),
and pelvic fins mostly unpigmented (vs. covered
in melanophores). Later-transitional larvae are
darker and can develop a series of parallel stripes
across the body. The other uniformly-marked transitional
snappers comprise L.
jocu and L.
cyanopterus. Transitional recruits of L.
jocu can appear quite similar to transitional
L. griseus; they share the stripes around
the eye, but in L.
jocu the thin indistinct bars persist without any body stripes developing. Transitional L.
cyanopterus have a quite different body
shape with a narrower and longer body and a wider
caudal peduncle (relative to body depth).
Juvenile
L. griseus either have a series of thin stripes on the side of the body
or are uniformly dusky. They lack the lateral spot of several other species. They
do not show the prominent bars of juvenile L.
apodus and they are wider-bodied with a narrower caudal peduncle than
juvenile L. cyanopterus.
They can share most body markings with juvenile L.
jocu, however the dark stripe through the eye and the thin dark stripes
on the side of the body intensify in L. griseus, while in juvenile L.
jocu the dark stripe through the eye becomes less prominent, the blue
line below the eye intensifies, and they develop indistinct bars not stripes.
| |
| Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Mostly
unmarked stage, usually from 10-13 mm SL:
Body: Pretransitional
larvae have two patches of melanophores on the body below the dorsal fin: under
the last two dorsal-fin spines and first dorsal-fin soft rays and then under the
middle of the soft dorsal fin. There is a band of surface melanophores along the
anterior half of the dorsal midline of the caudal peduncle and full-length along
the ventral midline of the caudal peduncle, extending forward and ending just
before a single large melanophore underlying the pterygiophores of the last anal-fin
rays. A patch of surface melanophores develops on the caudal peduncle filling
in progressively from ventral to dorsal in a mostly uniform pattern, without a
distinct clear bar anteriorly on the lower half of the caudal peduncle. There
are a few deep melanophores at the end of the lateral midline of the caudal peduncle.
Head: Melanophores on the head consist of a patch overlying the brain
and on the surface braincase and around the tip of the upper jaw; at the tip of
the lower jaw there are either no melanophores or distinctly fewer than at the
tip of the upper jaw. The opercular area is covered in iridescence extending down
to the pelvic-fin insertion. The inner cleithral surface of the gill cavity is
speckled with large melanophores and there are internal melanophores lining the
dorsal aspect of the peritoneum extending down to the vent and overlain by a silvery
camouflage layer.
Fin Spines: The dorsal and anal fin spines are relatively
stout, with prominent internal reticulations. There are fine serrations along
the anterior aspect of the anal and dorsal-fin spines at this stage, typically
persisting into transition in this species.
Fins: Melanophores on the
dorsal-fin membranes are concentrated between the third and eighth spines, present
on the dorsal midline at the base of the membrane and extending halfway or two-thirds
up the membranes. The dorsal-midline melanophores are often present from the second
to the tenth dorsal-fin spine bases. On the anal fin, there are melanophores on
the lower half of the membranes between the anal-fin spines and about half-way
up the second anal-fin spine. They continue on the lower half of the membrane
between the last spine and the first ray and the next membrane, followed by melanophores
only at the base of the membrane for the next few rays. Melanophores are concentrated
below the pterygiophores of the last two or three rays (often as one conspicuous
large melanophore) where they join the row along the ventral midline of the caudal
peduncle. There are often a few melanophores along the proximal portion of the
segmented caudal-fin rays in two places: between the bases of the lower-central
rays and along the lowest two or three rays, the latter often extending in a line
out along the rays.
| |
Transitional stage:
Transitional
larvae develop a relatively uniform scattering of melanophores on the body, usually
with some indistinct light bars on the upper side of the body. The lower half
of the caudal peduncle is uniformly speckled. Melanophores extend from the base
out to about two-thirds of the spinous-dorsal-fin membranes. A distinct stripe
extends from the eye forward to the tip of the upper jaw and two stripes develop
behind the eye and diverge. The tip of the lower jaw, the ventral half of the
head and the pelvic fins are lightly speckled in most transitional larvae. The
third dorsal-fin spine enlarges during transition, becoming noticeably stouter
and longer than the second or fourth. At this point the tips of the third, fourth,
and fifth dorsal-fin spines are close together (sometimes the tip of the fourth
reaches farther back than the tip of the fifth). | |
Juveniles:
Juvenile
L. griseus are overall dusky with a prominent dark stripe through the eye
and a pattern of thin parallel dark lines across the body, mostly below the lateral
line. The dorsal fin can have a dark band across the outer portion with white
edging. Some individuals occasionally have a blue line running under the eye.
They often have reddish ventral fins and can develop a prominent black spot at
the base of the pectoral fin. | | |
| Lutjanus
griseus larva |
| 12.2 mm SL |
| anterior spine serrations/cleithral
pigment |
| San Blas, Panama, SB81-019 |
|
 |
| |
 |
| |
 |
 |
| Lutjanus
griseus larva |
| 12.6 mm SL. DNA confirmed
ID |
| |
| San Blas, Panama, SB81-059 |
|
 |
| |
 |
| |
 |
| |
 |
| Lutjanus
griseus early transitional larva |
| 13.7 mm SL |
|
| San Blas, Panama, SB81-018B |
|
 |
| |
 |
| |
 |
| |
 |
| Lutjanus
griseus transitional larva |
| 12.4 mm SL, DNA confirmed
ID |
| note body widening,
3rd spine enlarging |
| San Blas, Panama, SB86-701 |
|
 |
| |
 |
| |
 |
| |
 |
| Lutjanus
griseus transitional recruit |
| 13.0 mm SL, DNA confirmed
ID |
| indistinct bar pattern |
| Glover's Reef, Belize,
CN |
|
 |
| |
 |
| |
 |
| Lutjanus
griseus, transitional recruit |
| 13.9 mm SL, DNA ID
pending |
| speckled transitional
variant |
| Isla Grande, Panama,
N7529a |
|
 |
| |
 |
| Lutjanus
griseus, transitional recruit |
| 14.8 mm SL, DNA ID
pending |
| speckled, incipient
stripes |
| Isla Grande, Panama,
N7529a |
|
 |
| |
 |
| | |
| |
| |
|
| | Diagnosis:
Modal fin-ray counts of D-X,14 A-III,8 are shared among most of the regional
Lutjanus spp., including L.
analis, L. apodus, L.
cyanopterus, L. griseus,
L. jocu and the deep-water snappers
L. buccanella, L.
campechanus and L. vivanus.
Transitional and juvenile L. apodus have a prominent pattern of vertical
bars without a lateral spot. (DNA) | |
Analogues:
Pretransitional
larvae (mostly-unmarked stage, usually from 12-15 mm SL) are separated from some
other Lutjanus spp. by having distinct serrations persisting on the anterior
profile of the anal and dorsal-fin spines (but shared by L.
griseus and L. jocu).
L. apodus larvae are distinguished from the L.
griseus type at this stage by having the dorsal-fin membrane melanophores
concentrated on the distal portion of the membranes, only a small patch on the
anterior third of the dorsal midline of the caudal peduncle, usually an incipient
bar pattern on the lower caudal peduncle, similar numbers of melanophores on the
tip of the upper and lower jaws, and often pigmentation along the longest pelvic-fin
membrane.
Early transitional L. apodus larvae can be separated
from L. griseus by having
incipient melanophore bars forming on the lower caudal peduncle (vs. uniform)
and having melanophores mostly on the distal half of the spinous-dorsal-fin membranes
(vs. proximal and base). Late transitional L. apodus larvae differ
from L. griseus by having
distinct vertical bars of larger melanophores on the body (vs. uniform, or indistinct
bars at most on the upper half of the body), numerous melanophores speckling the
cheek, thorax, and pelvic fins (vs. relatively lightly-marked), speckling on the
caudal peduncle reaching the base of the caudal fin rays (vs. an unpigmented area),
and the dorsal-fin spines are more evenly-sized, with the fifth spine almost as
long as the fourth with the tip extending farther back than the fourth (vs. a
short fifth, with the tip often overlapping the tip of the fourth in L.
griseus larvae). Transitional L. jocu show a similar bar pattern, but the lighter bars are narrower and the bar pattern becomes less distinct.
Juvenile L. apodus have no lateral spot
(vs. L. analis, L.
mahogoni, L. synagris,
and the deep-water snappers). They have prominent vertical bars which are absent
or indistinct in L. jocu, L.
griseus, and L. cyanopterus.
Juvenile L. cyanopterus
are also narrower-bodied, have a wider caudal peduncle, and do not share the blue
line under the eye. | |
| Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Mostly
unmarked stage, usually from 10-15 mm SL:
Body: Pretransitional
larvae can have a few melanophores on the body just below the dorsal fin base
where the future bars will develop: at the mid-spinous dorsal fin, the end of
the spinous dorsal fin and under the mid-soft dorsal fin. There is a patch of
melanophores along the anterior third of the dorsal midline of the caudal peduncle
and a full-length band of melanophores along the ventral midline of the caudal
peduncle extending forward and ending just before a single large melanophore underlying
the pterygiophores of the last anal-fin rays. A bar pattern begins on the lower
caudal peduncle as a patch without melanophores between two bars. There are a
few deep melanophores at the very end of the lateral midline of the caudal peduncle.
Head:
Melanophores on the head consist of a patch overlying the brain and on the
surface braincase and small melanophores around the tips of both the upper and
lower jaw (in similar numbers). The opercular area is covered in iridescence extending
down to the pelvic-fin insertion. The inner cleithral surface of the gill cavity
is speckled with large melanophores and there are internal melanophores lining
the dorsal aspect of the peritoneum extending down to the vent and overlain by
a silvery camouflage layer.
Fin Spines: The dorsal and anal fin spines
are relatively stout, with prominent internal reticulations. There are fine serrations
along the anterior aspect of the anal-fin spines at this stage, but disappearing
during transition.
Fins: Melanophores on the dorsal-fin membranes are
concentrated between the third and eighth dorsal-fin spines, predominantly on
the distal half of the fin-ray membranes and typically sparing the membranes adjacent
to the base of the fin. Some individuals have melanophores spreading down to meet
the dorsal midline, but only behind the fourth and fifth spines and later the
ninth and tenth spines (at the site of the future dark bars on the body). On the
anal fin, there are melanophores along the base of the spines and membranes, spreading
almost half-way up the second and third anal-fin spines. There are melanophores
on the lower portion of the membrane between the last anal-fin spine and the first
ray and the next membrane or two, followed by melanophores at the base of the
membrane for the next few rays. There can be a few melanophores between the bases
of the uppermost of the lower segmented caudal-fin rays and also on the lowest
two or three segmented rays, often extending out along the rays. |
| Transitional
stage:
Early transitional larvae develop a pattern of bars on the body,
beginning at the lower caudal peduncle where two dark bars first separate and
then bars progressively develop from the caudal peduncle anteriorly. Each bar
starts below the base of the dorsal fin and extends down with development. The
mid-body bars begin with three patches of melanophores: the first under the fourth
to sixth dorsal-fin spines, the second under the last two dorsal-fin spines and
first dorsal soft rays and the third under the middle of the soft dorsal fin.
Melanophores are limited to the outer half of the spinous-dorsal-fin membranes
at first, but progressively extend down during transition. Before any stripes
develop on the head, the tips of the upper and lower jaws are similarly speckled
with small melanophores. Even on lightly-marked transitional larvae, there are
some small melanophores on the thorax and the pelvic fin membranes. Early transitional
larvae have serrations on the anterior aspect of the first two anal fin spines,
but these are usually lost midway through transition. Late transitional larvae
have melanophores covering much of the body, but now the bars are made up of alternating
areas of smaller and larger melanophores. The lower caudal peduncle at this stage
has filled-in with melanophores and no longer has bars separated by non-pigmented
skin. By this point, melanophores have advanced down the spinous-dorsal-fin membranes
and do reach the base where they merge with the melanophores of the darker bars.
On the head, a stripe develops between the eye and the tip of the upper jaw and
two stripes diverge behind the eye. Small melanophores fill in and uniformly speckle
the cheek, operculum, and thorax as well as the pelvic fins. At this stage the
fifth dorsal-fin spine is not much shorter than the fourth and the tip of the
fifth definitely extends farther posterior than the tip of the fourth. |
| | | Juvenile
L. apodus have | | |
|
| Lutjanus apodus
larva | | 14.1 mm SL | |
| | San Blas, Panama, SB81-053 |
|  | | |  | | |  | | |  |
| Lutjanus apodus
early transitional larva | | 12.6 mm SL |
| | | San Blas,
Panama, SB81-054 | |  | | |  | | |  | | |  | | |  |
| Lutjanus apodus
transitional larva | | 14.4 mm SL |
| note mostly-bare dorsal caudal peduncle |
| San Blas, Panama, SB81-053 | |  |
| Lutjanus apodus
late transitional larva | | 15.8 mm SL, DNA
confirmed ID | | | | San
Blas, Panama, SB81-031 | |  | | |  | | |  | | |  |
| Lutjanus apodus
late transitional larva | | 14.8 mm SL |
| note similar 2,3,4, and 5th spine |
| | | San Blas, Panama,
SB81-031 | |  |
| Lutjanus apodus
late transitional larva | | 14.0 mm SL |
| variant, indistinct bars | |
| | San Blas, Panama, SB81-100 |
|  |
| | |
| |
| Wide-bodied
L. apodus/jocu variant (DNA ID pending): Wider body, stouter and longer dorsal
and anal fin spines, pretransitional spinous-dorsal-fin membranes spotted almost
to base. Transitional stages with less distinct bars. |
less distinct bars, | Lutjanus
sp. larva | | | 14.0
mm SL | | San Blas, Panama, SB81-112 |
|  | | |
 | | |
 | | |
 |
| |
 |
| |
| |
|
| | Diagnosis:
Modal fin-ray counts of D-X,14 A-III,8 are shared among most of the regional
Lutjanus spp., including L.
analis, L. apodus,
L. cyanopterus, L.
griseus, L. jocu and the deep-water snappers L.
buccanella, L. campechanus
and L. vivanus. Juvenile
L. jocu have indistinct vertical bars (if any), no lateral spot, a blue
line under the eye and are found primarily in mangrove habitats. (DNA) |
| Analogues:
Transitional recruits of L. jocu have no lateral spot and develop indistinct vertical bars in the same pattern as
L.
apodus, but with thinner light bars and no clear bars on the caudal peduncle.
L. cyanopterus can be
distinguished by a wider caudal peduncle (body depth after last dorsal ray goes
fewer than 2.5 times into predorsal body depth) and pigment concentrated at the
outer third of the pelvic fins vs. full-length in L. jocu. Transitional
L. jocu can appear quite similar to transitional L.
griseus since they both are mostly uniformly-marked with only indistinct bars. Some transitional L.
griseus differ in having a non-speckled area at the base of the caudal fin rays and most transitional recruits lose the indistinct bar pattern rapidly.
Juvenile L. jocu have no lateral spot
(vs. L.
analis, L.
mahogoni,
L. synagris, and the deep-water snappers)
and indistinct vertical bars (vs. prominent in L.
apodus). They are wider-bodied than L.
cyanopterus which also lacks the blue line
under the eye. Juvenile L.
griseus intensify the dark stripe through
the eye and develop thin dark stripes on the side
of the body, while in juvenile L.
jocu the dark stripe through the eye becomes
less prominent, the blue line intensifies, and indistinct
bars persist. |
| | Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular spine. |
| Transitional
stage:
Transitional recruits of L. jocu have a mostly-uniform
scattering of fine melanophores on the body with
indistinct bars made of narrow lighter bars against
a finely speckled background. |
|
Juveniles:
Juvenile L. jocu develop a thin blue line
from the top of the maxilla, under the eye, and
across the operculum. Otherwise they have few distinct
markings. They often show dark stripes from the
eye to the snout and behind the eye and can exhibit
a pattern of indistinct vertical bars. |
| |
|
| Lutjanus
jocu, transitional recruit |
| 16.8 mm SL, DNA confirmed
ID |
| bars indistinct, under-eye stripe |
| Carrie Bow Cay, Belize 1986 |
|
 |
| Lutjanus
jocu, juvenile |
| 22.9 mm SL, DNA confirmed
ID |
indistinct vertical
bars
blue under-eye stripe |
| Isla Grande, Panama,
N7529a |
|
 |
| |
 |
| |
 |
| |
|
| | |
| |
| |
14-rayed Lutjanus spp.,
other species |
| | | |
| |
|
| | Diagnosis:
Modal fin-ray counts of D-X,14 A-III,8 are shared among most of the regional
Lutjanus spp., including L. analis, L.
apodus, L. cyanopterus,
L. griseus, L.
jocu and the deep-water snappers L.
buccanella, L. campechanus
and L. vivanus. L.
analis is the only shallow-water snapper with 14 dorsal-fin spines that
has a lateral spot as juveniles and adults. Transitional larvae and recruits have
a barred pattern where the bars slant sharply down and to the rear. (DNA) |
|
Analogues:
Pretransitional larvae (mostly-unmarked,
usually from 13-17 mm SL) have relatively slender and smooth dorsal and anal-fin
spines, without the internal reticulations and anterior serrations found in L.
griseus, L. apodus,
and L. jocu. In addition, amongst
the regional Lutjanus spp. only L. analis and L.
cyanopterus often have no melanophores on or around the anal fin before
transition. Pretransitional L. analis also share the relatively slender
and smooth spines (and snout melanophores) with L.
cyanopterus, but have a distinctly-narrower caudal peduncle, melanophores
along the full-length of the pelvic-fin membranes or absent (vs. on the outer third of the
longest pelvic-fin membranes), and the tip of the second anal-fin spine is near
the tip of the third (vs. the tip of the second extending well past the tip of
the third in L. cyanopterus).
Transitional L. analis larvae develop
distinctive bars of melanophores that slant down sharply to the rear. In contrast,
the bars are vertical in transitional L.
apodus (also vertical, if present, on
L. jocu and L. cyanopterus).
Notably, L. analis often do not develop the characteristic lateral spot
until past the transitional stage (vs. early spot appearance in the 12-rayed
snappers). The latter share the bars and lateral-spot pattern. The bars of
transitional L. synagris
can also slope somewhat backwards and they share the location of the lateral spot
(mostly above the lateral line) with L. analis. Nevertheless the two species
can be distinguished by the dorsal soft-fin-ray counts as well as some subtle
marking differences: the lateral spot on L. analis, when present, is smaller
than that of transitional L. synagris
and in the latter the spot notably expands the bar while in transitional L.
analis the spot is the same width as the bar from which it forms. Another
consistent difference is the angle of the bar anterior to the lateral spot; in
L. synagris the bar curves
forward just below the dorsal fin and then slants backwards below the level of
the spot, while in transitional L. analis the bar slopes evenly down to
the rear from the base of the dorsal fin across the body. In addition, the melanophore-speckling
on the dorsal-fin membranes is mostly uniform on late-transitional L. analis,
while most L. synagris and
L. mahogoni at this stage
have a dark edging along the mid-dorsal fin. On new recruits the iridescent stripes
along the lower side of the body characteristic of L.
synagris are absent in L.
analis.
Juvenile L. analis have a distinct lateral spot.
They can be separated from the other shallow-water species with bars and a lateral
spot by the 14 soft dorsal-fin rays (vs. 12 in L.
synagris and L. mahogoni).
| | | Description:
Body wide and relatively thick with a sloping forehead and a large round eye and
large terminal mouth. Dorsal-fin base long and anal-fin base short. Prominent
stout dorsal, anal, and pelvic-fin spines and a large non-serrated preopercular
spine. | |
Pretransitional mostly-unmarked
stage, usually from 11-16 mm SL:
Body: A thin line of melanophores
develops on each side just below the base of the spinous dorsal fin, from the
third to fifth and the sixth to eighth spines (leaving an unpigmented dorsal midline
along the base of the fin). The row continues along the base of the soft dorsal
fin on the outer pterygiophore segments and the two rows on each side of the body
then merge into a band of melanophores lining the dorsal midline of the caudal
peduncle. There are a few deep melanophores at the end of the lateral midline
of the caudal peduncle. Along the ventral midline of the caudal peduncle there
can be only a single melanophore just forward of the first procurrent caudal-fin
ray, but it is often followed by several more.
Head: Melanophores on
the head consist of a dense patch overlying the brain and on the surface braincase.
There are small melanophores at the tip of the upper jaw and a small patch extend | | | | |
