Note (July 2009): My webguide
is a work in progress, with daily edits and new
family pages and photographs added continuously.
I am concentrating on the early life history stages
of snappers, gobies, and labrisomids right now.
My long-range plan is to first photograph my Caribbean
larval collections, then go on to my eastern Pacific
and Indo-Pacific collections.
Why keep my guide on the web? The main reason is that books and papers require
that information be frozen in time: essentially a snapshot of knowledge at a particular
moment. We used to accept this as inevitable and many of us probably don't even
think about it. But it is clear that scientific information is continuously being
updated and remodeled and it is somewhat discordant, and certainly inefficient,
to produce and package the results in an occasional bolus. Unfortunately, most
of us accept that authors will have their additions, changes, and errata somewhere
on their desk and inaccessible (we hope only until the next edition). Even worse,
when the subject is a compendium of information, such as a guide, authors often
wait until it is in some form "complete" before submitting it to publication.
Woe be unto the perfectionist in this case, for it may take a lifetime for some
people to decide they are ready. That is all 20th-century thinking- there is no
reason in the age of the internet not to have a work in progress made generally
accessible.
INTRODUCTION
Virtually
all of the thousands of species of tropical
reef fishes have a larval stage that spends
weeks to months in the open ocean before returning
to the reef to settle. This transition from
pelagic larvae to settled juveniles is a profoundly
important time for reef fishes. During this
settlement transition, which usually occurs
on moonless nights, the larvae have critical
decisions to make: they need to select an
appropriate habitat, avoid the ubiquitous
predators, and change their shape and color
for life on the reef. Understanding this early-life-history
process is clearly important to understanding
the population dynamics and, more broadly,
the biogeography, ecology, and evolution of
coral reef fishes.
Despite its undoubted
importance, this transition has not been comprehensively studied and one of the
reasons this may be true is the lack of information on late-stage larvae. I have
been collecting these larvae, mostly by netting at a nightlight directly over
the reef, but also with crest-nets and other techniques for many years. In addition,
I have focused my daytime collecting on what some of us call "new recruits", the
recently-transformed juvenile fishes that suddenly appear in the morning on the
reef.
For
some reason, almost all of the reef-fish larvae
I collect at a nightlight are late-stage larvae
ready to settle onto the reef. This is not an artifact
of their attraction to the light: I have towed plankton
nets in the area and I get a similar size complement
of larvae. In addition, other techniques to collect
incoming larval fish, such as crest nets, yield
the same size categories of larvae.
The
simplest explanation for this phenomenon is
that larval fish that are ready to settle
somehow maneuver themselves into on-reef currents,
perhaps just by rising to the surface water
layer. There has been recent research indicating
that reef-fish larvae are good swimmers and
can actively orient towards reefs. Whichever
way they manage it, almost all of the larvae
I capture are around the particular settlement
size range for their species. This can be
very helpful in identifying larvae.
REFERENCES
There are a number of excellent
books on larval identification and the early life history stages of fishes. Most
include copious drawings of reef-fish larvae and also focus on the earlier stages
of fish larvae: Jeff
Leis at the Australian Museum has published his opus (or opuses) with comprehensive
coverage of the Indo-Pacific species of reef and shore fishes.
For
the Atlantic, there is the latest larval fish
book edited by Bill Richards:
Richards, W.J. (2005) Early Stages Of Atlantic
Fishes: An Identification Guide For The Western
Central North Atlantic, Vols. 1 and 2
It covers pelagic fishes and deepwater fishes
as well as shore and reef species and captures
the state of the art from a couple of years
ago. Lastly, the classic book by Michael Fahay
(1983), the Guide to the Early Stages of
Marine Fishes Occurring in the Western North
Atlantic Ocean, deals mostly with the
temperate ichthyoplankton of the Atlantic
coast of the US, but with some overlap of
coverage.
Larval descriptions have been illustrated
with line drawings for many years and even
now virtually all books and scientific papers
use line drawings almost exclusively. There
are a few benefits to the use of drawings
for early stage fishes; for example, otherwise-transparent
details such as head spines and pectoral fin
rays can be highlighted. Nevertheless, it
is most likely that the main reason for line
drawings is the cost of printing photographs
and the necessity to limit the number of pages
and illustrations in the publishing process.
But, in the near future, and however resistant
we may feel to change, libraries certainly
will be merged into central databases and
printing presses and paper may well go the
way of the neighborhood bookstore. Line drawings
may seem as quaint as the watercolors used
for the illustrations in 19th century species
descriptions.
There are many limitations to line drawings.
Perhaps the most problematic is that melanophores,
especially small or delicate ones, disappear
against a black line drawing and these melanophores
are often the most critical element in larval
identifications. The idealization of the drawing
can also distort the real appearance of the
larvae, emphasizing outlines and de-emphasizing
shading, form, and especially color. Furthermore,
there is usually marked variation in the appearance
of fish larvae, both functional (such as melanophores
expanded or pinpoint) and inherent (incomplete
melanophore complements are common). This
variation among individuals certainly argues
against presenting an ideal. In addition,
the development of metamorphic markings and
morphological changes is a continuous process
and it is, of course, impossible to pick one
or two images to capture the information.
Now
that digital photography and web publishing
has streamlined the use of photography, it
is possible to present many illustrations
of a single larval type and get around the
limitations of choosing a single or only a
few diagnostic images. I hope to emulate the
actual process of identification, which is
to use a variety of views and backgrounds
to create a gestalt that quickly identifies
a larval type without following a key or character
list to arrive at a diagnosis.
Along
a similar vein, most of the literature to
date bravely (or is it quixotically) tries
to verbally describe larval shapes and melanophore
patterns. More text is usually favored over
more illustrations, probably because of the
decreased costs of publication. This obviously
limits the amount of information captured
since it is technically impossible to render
three-dimensional shapes and patterns into
words. Furthermore, the location of markings
and structures can only be given relative
to
other
landmarks and is always limited in precision by
the amount of text that can be printed, or even
tolerated, by a reader. I therefore will try to
avoid the temptation to add reams of description
to the photographs, but I will insert a hopefully
pithy verbal description when it is necessary to
highlight relevant features.
I present the photographs of larvae usually with
a dark background, sometimes along with a matched
photo taken against a light background so that the
black melanophore pattern, and especially internal
melanophores, can be seen. Photographs against dark
backgrounds, like line drawings, can hide the small
or edge melanophores that are often diagnostic for
larval types. I also include detail photographs
on pertinent features of the larvae that may be
critical to identification or of specific interest.
If there are transitional forms of interest, photographs
of those are included. I also hope to add images
of new recruits, especially for those groups with
many similar species and distinctive juvenile markings.
THE
DEFINITION OF LARVAE
Please
note that most reef-fish biologists use the loose
definition of the word "larvae", i.e. the stages
of development before settlement to the reef, if
they show a morphological difference from settled
juveniles.
This definition of early stage fishes excludes
the pelagic juveniles of some species who
are typically indistinguishable from reef-based
juveniles and often float with drift objects:
these fishes have essentially settled onto
a drifting platform. As one can imagine,
the few species that do this regularly are
annoying to us mainly because they defy
the usual interpretations of what defines
"larvae", "settlement", and "pelagic larval
duration". Reef fishes in this category
include the Sargassum
algal drift-associated juveniles, to some
degree or another: triggerfishes (Balistidae),
the damselfishes Abudefduf
spp. (Pomacentridae), filefishes
(Monacanthidae),
barracudas (Sphyraenidae), triplefins (Lobotidae),
pipefishes and seahorses (Syngnathidae),
and needlefishes (Belonidae).
Another
intriguing discovery is the occasional pelagic adult
reef fish. This is new information and may explain
the sometimes contradictory findings of the degree
of larval dispersal derived from study of larval
pelagic durations versus the observed degree of
gene flow in phylogenetic studies. The elusive pelagic
adult is quite intriguing, and I hope to pursue
this curious creature in future expeditions. Several
sources of information indicate that this is happening,
although to what degree is completely unknown. The
original observation was by Ross
Robertson who saw adults of the slingjaw wrasse,
Epibulus insidiator,
rising off of reefs and drifting away offshore (in
Palau, a part of Micronesia, in the Western Pacific).
Then there have been records of the rare adult reef
fish caught in light traps far offshore (reports
from the Great Barrier Reef) and observations of
adult reef parrotfishes in schools in pelagic waters
far from reefs (Enric Sala reports from diving in
Cuba).
The significance of this phenomenon is
unknown. Perhaps it is a way of relocating
among reef systems for more advantageous
feeding or reproduction, although this would
require that the likelihood of returning
to a reef outcrop be greater than the likelihood
of being eaten by a tuna... somewhat hard
to imagine. Alternatively, some pelagic
adults may not be reef emigrants, but could
be lost pelagic juveniles approaching maturity,
perhaps associated with drift structure
for protection, and haplessly waiting for
a chance encounter with a reef. Larval mortality
schedules must have a tail to the distribution
and thus permit some small but real fraction
of pelagic larvae to persist through transformation
(if obligatory at some point) and even grow
to adulthood offshore.
HOW DO
I IDENTIFY REEF FISH LARVAE?
This
is perhaps the most common question I am asked, since there is a bewildering variety
of fish larvae in almost any collection. In addition, the possible candidates
for any particular larva in the Caribbean or the eastern Pacific include a thousand
reef-fish species, and perhaps another thousand other shorefish species and deepwater,
midwater, and pelagic fishes as well. That total rises to many thousands as one
approaches the center of diversity near Indonesia in the central Indo-Pacific.
Fortunately, larval fishes, especially at later stages, are not uniform or even
broadly similar; in fact they can often have even more divergent characters
than do the adults. For example, virtually all reef fishes have round eyes after
settlement, while their larvae can have widely-varying eye morphologies, often
narrowed or tilted and sometimes exhibiting bizarre shapes. In addition, some
taxa have larvae with greatly-extended fin spines or rays, sometimes many times
longer than the larva itself. There is also a great diversity in spine development,
with many larvae having complex spine ornamentation on the head or fins, often
lost or inconspicuous on adults. Finally, an important character at higher taxonomic
levels for fishes is the number of myomeres, the muscle segments making up the
body. These are hidden under pigment and skin in juvenile and adult fishes, but
are clearly obvious and countable in most larval fishes.
Some
taxa fortunately develop the typical juvenile appearance as late-stage larvae
and are thus easy to identify from known-juvenile markings and coloration. Typically
these larvae still do show some subtle adaptations to pelagic life, often a silvery
sheen and shades of black, gray and brown or red instead of the usual bright colors.
Red does not penetrate seawater well and would appear gray, especially in low-light
conditions. Examples of fishes using this strategy include the angelfishes (Pomacanthidae),
the butterflyfishes (Chaetodontidae),
and the squirrelfishes (Holocentridae). A larval Pomacanthus arcuatus,
only 8.2 mm SL, is pictured at right.
Others live among drift
algae and are camouflaged by markings similar, but not identical, to those of
settled juveniles. The camouflage is an adaptation to avoid being eaten by the
ubiquitous pelagic predators which target floating objects in the open ocean,
such as tunas and mahi-mahi (dolphinfish). Larvae following this strategy include
some pipefishes and seahorses (Syngnathidae),
triggerfishes (Balistidae),
and filefishes (Monacanthidae).
Identification to genus
and species in larvae with a more generic appearance can be much more difficult
(excuse the pun). Most generic types of reef-fish larvae are transparent and very
small and, while they are alive, look just like tiny slivers of glass with eyes.
When there are just a few genera or species in a group, the fin ray counts are
usually diagnostic to species. In some of the more
speciose
groups with large sets of closely-related species, such as the gobies (Gobiidae)
and the gobioids (Gobioidei), the scaled
blennies (Labrisomidae), the snappers
(Lutjanidae), the seabasses and groupers
(Serranidae), as well as parrotfishes
(Scaridae), wrasses (Labridae),
and some damselfishes (Pomacentridae),
the number of possible species can be overwhelming and I have to resort to some
other method of identification. There are a variety of ways to do this, some simple
and some using the latest molecular techniques.
FIRST,
USE THE PROCESS OF ELIMINATION...
Most
reef-fish larvae do resemble juveniles and adults in basic form, and, especially,
in the number of fin spines and rays and myomeres. This is the primary method
of identification for early life history stages and works almost all the time
for family, most of the time for genus, and often for species.
Of
course, this is essentially a process of elimination and it is much easier in
the Caribbean, with only a few hundred possible candidates, versus the Indo-Pacific
where there can be thousands of reef-fish species occurring at one particular
site. The eastern Pacific region is generally similar to the Caribbean in numbers
of reef-fish species. The majority of my specimens are Caribbean, most from the
San Blas Islands of Panama, so I will start developing the guide for these fishes.
Other Caribbean sites from which I have collected include Belize, Puerto Rico,
and St. Thomas. I have also collected fishes at the Brazilian island of Fernando
de Noronha, where there is an unusual complement of reef fishes, some endemic
and some widespread Caribbean forms.
A particularly useful
variant of the process of elimination is the examination of fishes from isolated
regions where only a subset of the group is present (i.e. depauperate locations).
This is a very useful method in some groups where the larvae of similar species
can be very difficult to separate. For example, there are numerous very similar
gobies of Coryphopterus
spp. in the Caribbean, but only one species, C.
glaucofraenum, ranges south to Noronha in Brazil.
Another
useful variant is using the similarity with sibling species in the eastern Pacific
Ocean to refine the process of elimination. When identifications of larval types
becomes difficult because there are several Caribbean species that all share fin
ray counts, the situation may be different on the Pacific side of Central America.
The isthmus of Panama rose about three million years ago, and there are numerous
reef-fish genera with species on both sides of the isthmus, often as very similar
species pairs or "sibling species". On the other hand, some genera occur on only
one side, and the presence (or even absence) of a particular larval type on
one
side or the other can contribute to the process of elimination and confirm an
identification. For example, the sleeper Erotelis
smaragdus shares its fin ray counts with other Caribbean sleepers, making
it a problem for identification. But, in the eastern Pacific, the sibling species
Erotelis armiger has a unique fin ray count among the eastern Pacific sleepers.
I now have collected a series of sleeper
larvae with
that fin ray count from near the Galapagos Islands, and they are almost identical
to the putative Erotelis smaragdus
larval type... thus confirming the identification for the Caribbean larval type.
Another example is an unusual Caribbean goby larval type with a fin ray count
matching several Ctenogobius
spp., but also the monotypic Evorthodus
lyricus. Again, I have collected an identical larval type from the eastern
Pacific Ocean, where, fortuitously, there are only two Ctenogobius spp.
(neither of which match the fin ray count), but there exists the sibling of the
Caribbean Evorthodus species, Evorthodus minutus, with the appropriate
fin ray count. That confirms the identification of the Caribbean larval type as
Evorthodus lyricus.
THEN,
LOOK FOR MISSING LINKS (TRANSITIONAL LARVAE AND TRANSITIONAL RECRUITS)
On close examination, many
larval types have very characteristic and remarkably consistent patterns of black
spots (melanophores). Often, they also have specific patterns of other chromatophores.
Pigment cells in fishes include the classic melanophores which comprise black
and brown spots, iridophores which are mirror-like spots that simply reflect light
and often appear silvery, leukophores which are white, and xanthophores which
range from yellow to orange to red. Unfortunately xanthophore pigments dissolve
rapidly in solvents and are not usually preserved.
Now
why would these markings be so prominent and so specific? I think pelagic larvae
use these for species identification. Perhaps they prefer to travel together while
in the open ocean and settle together. I have noticed that sometimes several new
recruits of a particularly uncommon species will show up on the same rock on the
same morning, with no other recruits for miles around. Interesting....
Fortunately,
in most reef fishes the larval markings are quite different from the juvenile
markings. Larval melanophores are typically large, often stellate, individual
black spots that extend below the skin surface. These markings are replaced during
the settlement transition by metamorphic melanophores in the patterns shown by
juveniles on the reef. These arrays of additional melanophores (and sometimes
leukophores and iridophores), are usually much smaller and right at the skin surface.
In addition, they are typically numerous and in dense patches that often begin
on the head and develop posteriorly following the pattern of the juvenile markings
of the species. This Labrisomus haitiensis transitional larva shows the
prominent three larval melanophores surrounded by the patches of fine metamorphic
melanophores. In many species, this transition can take days and often the larval
markings coexist with the developing juvenile patterns. These metamorphic melanophores
are invaluable for identifications.
So
an excellent method of identifying larvae is to find the occasional pelagic larva
that has started to transform and is developing the characteristic juvenile markings
while still in the water column. Alternatively, I often have collected new recruits
on the reef that still have some identifiable larval melanophore patterns, i.e.
transitional recruits. Both of these forms
of missing links can indicate what species that type of larvae represents.
THE GOLD STANDARD:
DNA SEQUENCE MATCHING
The most recent advance is the use of DNA sequencing to identify larvae. This
technique is rapidly becoming the gold standard for larval identification. Once
a library of sequences is known for a group of species, then individual larvae
can be sequenced and matched to the known species. This method can be expensive
and requires a full set of species-specific sequences for the group, which is
not always easy to assemble. Nevertheless, I have started a comprehensive larval-adult
matching project using mitochondrial DNA sequences and have started to resolve
some of the more tricky ID situations, such as the damselfish Stegastes
spp., the labrid Halichoeres
spp., the parrotfish Sparisoma
spp., the snapper Lutjanus
spp., and the gobies Bathygobius
spp., Lythrypnus
spp., and Coryphopterus
spp. In addition to confirmatory IDs, sequence analyses are wonderful
tools for discovering new and/or cryptic species: indeed, recent analyses I have
done have discovered cryptic species among the Caribbean Coryphopterus
spp. and that two cryptic species of bonefishes, Albula spp., coexist
in equal numbers in my Panama collections. Another benefit of sequencing reef
fishes is discovering surprising and unexpected patterns of relatedness (although a long list of caveats should follow; phylogenetic relationships require multiple loci and appropriate statistical analyses to ensure any robustness!). My sequences
for the labrids confirmed (in agreement with other published trees) that Halichoeres
maculipinna is only distantly related to the other Halichoeres
spp. and may be closer to the Thalassoma
spp. In addition, with collections over wide geographic ranges, one can
assess the degree of genetic divergence of isolated island populations. My sequences
reveal that this divergence sometimes seems to show little relation to the duration
of the pelagic larval phase. I cannot really explain this counter-intuitive finding
and it surely indicates that the relationship between dispersal and speciation
is not a simple one (to say the least). Clearly, a plethora of profound insights
are about to arrive with the advent of widescale DNA sequencing of reef fishes.
FINALLY, AQUARIUM
RAISING OF LARVAE
Another
method is to isolate the larva and raise it in an aquarium tank until it develops
identifiable juvenile markings. This method can be labor intensive and requires
the larva not to be so delicate that it dies from handling. In addition, there
is a piscine Heisenberg Uncertainty Principle, which is that one cannot keep the
larva in preservative and also raise it alive. If it is possible to examine the
living larva close enough (and even photograph it) and then raise it, an identification
can be made.
An alternative, although much
more intensive and expensive, method to document the early life history of reef
fishes is to raise the fish from the egg through the larval period in the laboratory.
This is being achieved more recently as techniques for feeding notoriously delicate
reef-fish larvae are perfected. There are some indications, however, that laboratory-raised
larvae may look somewhat different from "real" larvae since they are certainly
living in unnatural conditions and may grow at different rates. In addition, they
would be undoubtedly confused as to when and whether they should enter transition.
TERMINOLOGY
AND LAYOUT OF LARVAL IDENTIFICATIONS IN THE GUIDE
Identifications
will be presented to the lowest taxonomic level of which I am reasonably sure.
A question mark after the genus or species name indicates that I am not reasonably
sure of the identification. This could mean that the identification is simply
of the most likely species without any other good reason to choose it, or, less
commonly, that the identification fits by some criterion but I am suspicious because
it doesn't "look right". Some larval types may, of course, include other closely-related
species that have identical larval features. If this is the case, it will be indicated
by a plus sign after the species name. If the features of the larval type are
unique, or all of the related species sharing the fin ray counts are accounted
for, then there will be no plus sign.
Diagnosis:
If necessary, I explain how the identification is made in a diagnosis paragraph.
The critical features for the ID are highlighted. If it is needed, the methods
I have used for larval identification, such as unique and specific morphology
or fin ray counts (U), the process of elimination (PE), DNA sequence matching
(DNA), or raising in captivity (R) are indicated at the end of the diagnosis paragraph.
Analogues: For most larval descriptions, the diagnosis paragraph is sufficient
to separate larval types, but, for some groups of species with similar-appearing
larvae, such as the gobies, I often include an additional paragraph on how that
larval type can be separated from other closely-allied larvae.
Terminology: In the text, larvae are immature fishes caught in waters above
or off the reef (usually at night), typically with adaptations to open ocean dwelling,
such as transparency or silvery coloration, extended spines and often a different
set of markings from juveniles of the species. Transitional larvae are immature
fishes caught in waters above or off the reef (also usually at night) who have
started to develop juvenile markings and morphology. Transitional recruits are
fishes associated with the reef substrate who have retained remnants of larval
markings along with their juvenile markings and morphology. They typically are
out during the day and behave as normal juveniles. Recruits are newly-settled
fishes associated with the reef substrate (let's say less than a couple of weeks
on the reef). Juveniles are young fishes on the reef who are no longer newly-settled.
Each photograph is associated
with a caption including the identification to the lowest taxonomic level possible,
the standard length (SL) in millimeters of the specimen, as well as the collection
location and collection code number. Lastly, important features that need to be
highlighted in the illustration are often included in parentheses following the
collection information. The data associated with the collection numbers (specific
location, date, etc.) can be found in my inventory
files, which are progressively being updated and posted to the web.
PERMISSIONS
My
photographs are freely available for reproduction and use in non-commercial applications.
Please e-mail me for permissions, if warranted (for my e-mail address use the
name ben followed by @coralreeffish.com). The web versions posted here are mostly
about 500 pixels wide and run from 20 to 50 kb. I have larger resolution versions,
usually about 1.5 mb jpegs, available for uses that require better resolution.
THE CARIBBEAN REEF FISH SPECIES LIST
(including the Gulf of Mexico)
Fish families following Randall's
book, but with updated, expanded, and revised
species lists
excluding elasmobranchs
including numerous species
found in non-reef habitats (if the family
has reef-associated members)
but sometimes excluding sets
of deep-water species (over ~30 m depth)
Pellona harroweri Coastal pellona
(Panama to Brazil, Pristigasteridae)
Sardinella aurita Round sardinella
Sardinella janeiro (widespread, =
Sardinella brasiliensis)
FAMILY ENGRAULIDAE
Anchoa belizensis Belize anchovy
(freshwater, Belize) Anchoa cayorum Key anchovy Anchoa colonensis Narrow-striped
anchovy (Caribbean only, replaces A.
hepsetus) Anchoa cubana (widespread) Anchoa filifera Longfinger anchovy
Anchoa hepsetus Broad-striped anchovy
(Gulf of Mexico northwards, Venezuela southwards)
Anchoa lamprotaenia Big-eye anchovy
Anchoa lyolepis Shortfinger anchovy
Anchoa mitchilli Bay anchovy (Gulf
of Mexico northwards) Anchoa parva Little anchovy (Caribbean
only, replaces A. mitchilli) Anchoa spinifer Spicule anchovy (Panama
to Brazil) Anchoa trinitatus Trinidad anchovy
(Gulf of Venezuela to Trinidad)
Anchovia clupeoides Zabaleta anchovy
Anchoviella blackburni (Gulf of
Venezuela only) Anchoviella elongata Elongate anchovy
(Belize to Panama and Colombia) Anchoviella perfasciata (widespread)
Cetengraulis edentulus Atlantic
anchoveta
Engraulis eurystole Silver anchovy
(Florida northwards and Venezuela southwards)
Lycengraulis grossidens Atlantic
sabretooth anchovy (Gulf of Venezuela eastward
plus Belize)
(excluding numerous deep-water taxa from 20-500
m depth)
Ahlia egmontis Key worm eel
Aplatophis chauliodus Tusky eel
Aprognathodon platyventris Stripe
eel
Apterichtus ansp Academy eel
Bascanichthys bascanium Sooty eel
(Gulf of Mexico and Florida north) Bascanichthys inopinatus (Puerto
Rico +?)
Bascanichthys scuticaris Whip eel (Gulf
of Mexico and Florida north)
Callechelys bilinearis Twostripe
snake eel Callechelys guineensis Shorttail
snake eel
Echiophus intercinctus Spotted spoon-nose
eel Echiophus punctifer Stippled spoon-nose
eel
Ichthyapus ophioneus Surf eel
Myrichthys breviceps Sharptail eel Myrichthys ocellatus Goldspotted
eel
Myrophis anterodorsalis Longfin
worm eel Myrophis platyrhynchus Broadnose
worm eel Myrophis punctatus Speckled worm
eel
Ophichthus cylindroideus Ophichthus gomesii Shrimp eel Ophichthus ophis Spotted snake eel Ophichthus puncticeps Palespotted
snake eel Ophichthus rex (Gulf of Mexico)
Quassiremus ascensionis Black-spotted
snake eel
FAMILY CONGRIDAE
(excluding
numerous deep-water taxa from 20-500 m depth)
FAMILY OPHIDIIDAE, SUBFAMILIES
BROTULINAE AND NEOBYTHITINAE
(excluding
numerous deep-water taxa from 20-8000 m depth)
Brotula barbata
Petrotyx sanguineus
FAMILY OPHIDIIDAE, SUBFAMILY
OPHIDIINAE
(excluding
numerous deep-water taxa from 20-500 m depth)
Lepophidium brevivarbe
Ophidion beani (Florida and Gulf
of Mexico) Ophidion grayi (Florida and Gulf
of Mexico) Ophidion holbrookii (= Ophidion
holbrooki) Ophidion josephi (Florida and Gulf
of Mexico) Ophidion lagochila Ophidion marginatum Ophidion nocomis (Antilles) Ophidion selenops (Florida and Gulf
of Mexico) Ophidion welshi (Florida and Gulf
of Mexico, incl. Ophidion marginatum?)
Cynoscion acoupa (Panama to Argentina) Cynoscion arenarius (Florida and
Gulf of Mexico) Cynoscion jamaicensis Cynoscion leiarchus (Nicaragua to
Brazil) Cynoscion microlepidotus (Venezuela
to Brazil) Cynoscion nebulosus Spotted weakfish
(Florida and Gulf of Mexico) Cynoscion nothus Silver seatrout
(Florida and Gulf of Mexico) Cynoscion similis (S. Caribbean) Cynoscion virescens (Nicaragua to
Brazil)
Larimus breviceps Shorthead drum Larimus fasciatus (Florida and Gulf
of Mexico)
Leiostomus xanthurus Spot (Florida
and Gulf of Mexico)
Lonchurus elegans (S. Caribbean)
Lonchurus lanceolatus (S. Caribbean)
Macrodon ancylodon King weakfish
(SE Caribbean)
Menticirrhus americanus Southern
kingfish Menticirrhus littoralis Menticirrhus saxatilis (Florida and
Gulf of Mexico)
Micropogonias furnieri Micropogonias undulatus Atlantic
croaker (Florida and Gulf of Mexico)
Nebris microps (Colombia to Brazil)
Odontoscion dentex Reef croaker
Ophioscion costaricensis (Costa
Rica and Suriname) Ophioscion panamensis (Belize to
Panama) Ophioscion punctatissimus (Panama
to Brazil, and Puerto Rico)
Eugerres brasilianus (Belize, Cuba
south to Brazil?) Eugerres mexicanus (Mexico Guatemala
FW, Rio Usumacinta) Eugerres plumieri Striped mojarra
(Florida, Gulf of Mexico to Cuba, Panama?)
Hypleurochilus bermudensis (Bermuda,
Bahamas to Florida) Hypleurochilus caudovittatus (Florida)
Hypleurochilus geminatus (Florida
north) Hypleurochilus multifilis (N. Gulf
of Mexico) Hypleurochilus pseudoaequipinnis
Oyster blenny (prior part of H. aequipinnis)
Hypleurochilus
springeri Orangespotted blenny
Hypsoblennius brevipinnis (Pacific
species, invading Panama Canal) Hypsoblennius exstochilus (N. Caribbean
islands) Hypsoblennius hentz (often Hypsoblennius
hentzi, US to Yucatan) Hypsoblennius
invemar Hypsoblennius ionthas (N. Gulf of
Mexico, US east coast)
Lupinoblennius nicholsi (N. Gulf
of Mexico) Lupinoblennius vinctus Mangrove blenny
(= Lupinoblennius dispar)
Gobiosoma bosc (US east coast and
Gulf of Mexico) Gobiosoma ginsburgi (US east coast)
Gobiosoma grosvenori (Florida, Bahamas,
and NE Venezuela) Gobiosoma hemigymnum (West Indies) Gobiosoma
hildebrandi (Panama Canal and environs)
Gobiosoma longipala (N. Gulf of
Mexico) Gobiosoma robustum (Gulf of Mexico) Gobiosoma schultzi (Lake Maracaibo,
Venezuela) Gobiosoma
spes (Central American coast (and
Greater Antilles?)) Gobiosoma spilotum (Panama Canal
Zone) Gobiosoma yucatanum (Yucatan to Honduras)
Fortunately,
in most reef fishes the larval markings are quite different from the juvenile
markings. Larval melanophores are typically large, often stellate, individual
black spots that extend below the skin surface. These markings are replaced during
the settlement transition by metamorphic melanophores in the patterns shown by
juveniles on the reef. These arrays of additional melanophores (and sometimes
leukophores and iridophores), are usually much smaller and right at the skin surface.
In addition, they are typically numerous and in dense patches that often begin
on the head and develop posteriorly following the pattern of the juvenile markings
of the species. This Labrisomus haitiensis transitional larva shows the
prominent three larval melanophores surrounded by the patches of fine metamorphic
melanophores. In many species, this transition can take days and often the larval
markings coexist with the developing juvenile patterns. These metamorphic melanophores
are invaluable for identifications.
