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Thalassoma
Halichoeres
Xyrichtys
Doratonotus
Clepticus
Decodon
Bodianus
Lachnolaimus
The wrasses are a particularly diverse and abundant family of reef fishes, with numerous species that occupy essentially all reef, rock, and grassbed habitats in the Caribbean. The bluehead wrasse, Thalassoma bifasciatum, is the single regional representative of a prominent labrid genus and is ubiquitous on Western Atlantic coral reefs. Another large genus of wrasses, Halichoeres, has more than 80 species throughout the tropics with many regional representatives, not all of which are closely related. There are three local razorfishes in Xyrichtys (note that Xyrichtys is frequently misspelled as Xyrichthys) and two hogfishes in Bodianus. The remaining labrid genera in the region are mostly monotypic: Doratonotus megalepis, Lachnolaimus maximus, Clepticus parrae, and the deep-water wrasse Decodon puellaris (the latter two species have a sibling species in the eastern Atlantic and in the eastern Pacific, respectively).

Labrid larvae can be recognized by the absence of head spines, long and continuous dorsal and anal fins with slender spines, a relatively wide caudal peduncle, stub-like pelvic fins, a pointed snout with a small terminal mouth and typically light markings (none or melanophores mostly on the fin-ray membranes). Notably, there is no row of melanophores along the anal-fin base, which separates labrid larvae from many similar-appearing groups, such as larval scarids, labrisomids, chaenopsids, dactyloscopids, and gobies. While most tropical labrid larvae fit this general pattern of small and mostly unpigmented larvae, two genera are exceptions: larval Lachnolaimus maximus are fully-pigmented and Decodon melasma have an unusual and large late larval stage with a pattern of bars on the body.

   
Pre-transitional labrid larvae can have unusual eye morphology: many larval Halichoeres and Thalassoma have eyes that are narrowed vertical ovals, usually tilted backwards, but sometimes forwards. Larval Xyrichtys have markedly-narrowed vertically oval eyes. Other larval labrids, such as Doratonotus megalepis, have round eyes throughout development. These eye shapes likely reflect differing life styles of these early life history stages in the pelagic environment.
While genera are relatively easily distinguished, congeneric labrid larvae can appear similar, if not identical. Several species of Halichoeres share melanophore patterns and only become recognizable to species during transition. Larval razorfishes, Xyrichtys, have no melanophores and do not diverge in appearance until juvenile markings develop (however their evanescent chromatophore patterns may be species-specific). Some Caribbean labrid larvae require DNA sequencing for identification to species.
The labrids below are presented in order of increasing numbers of dorsal-fin spines: from 8 to 14 in the regional labrids. Fin-ray counts generally separate Caribbean genera well.
Notes on Thalassoma
This large genus of labrids has only two representatives in the western Atlantic: the widespread Bluehead Wrasse Thalassoma bifasciatum and its Brazilian relative T. noronhanum. Several more species are found in the eastern Pacific and many others are native to the Indo-Pacific. The larvae of Pacific species are almost identical to the larval T. bifasciatum described below, but are missing the patch of melanophores at the front of the dorsal fin. Although usually described as having no melanophores, many larval Thalassoma I have collected in the Pacific Ocean have the same small melanophores along the edge of the membranes of the dorsal and anal fins and upper and lower membranes of the caudal fin as are found on larval T. bifasciatum. Note however, that only larvae in particularly good condition will have intact edges of the membranes.
Edge melanophores on a T. grammaticum larva, 13.0 mm SL, Clipperton Island.
larval Thalassoma bifasciatum
Thalassoma bifasciatum
Diagnosis: The fin-ray count of D-VIII,13 A-III,11 indicates Thalassoma bifasciatum.
Analogues: Larval Thalassoma have distinctive edge melanophores along the median fins, although these melanophores may be absent in earlier stages and where the fins are not fully intact. Halichoeres larvae have additional patches of melanophores along the mid and rear dorsal and anal-fin membranes vs. the solitary anterior patch on the dorsal-fin spines of Thalassoma bifasciatum. Larval Bodianus rufus can appear somewhat similar but have a wider body, a larger round eye, and the dorsal-fin origin is distinctly farther back on the body.
Description: Body relatively thin, narrow, and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide. Melanophores limited to the fin-ray membranes, in a group along the first two or three dorsal-fin spines and then on the membrane fringes along the dorsal, anal, and caudal fins. Series of larvae show development of the eye from vertically oval to round (round in many larvae captured over the reef).
Transitional recruits develop a prominent black spot on the front of the dorsal fin, a wide black stripe along the side from nose to tail and a dorsal stripe from the top of the head along the base of the dorsal fin. Transitional recruits on the reef commonly show remnants of the melanophores on the fin-membrane edges characteristic of the larvae.
Thalassoma bifasciatum larva
11.3 mm SL
San Blas, Panama, SB81-051
larval Thalassoma bifasciatum
  larval bluehead wrasse
  settlement bluehead wrasse
Thalassoma bifasciatum new recruit
11.4 mm SL
San Blas, Panama, SB81-001
juvenile bluehead wrasse
Notes on Halichoeres
This large genus includes eleven regional species, two of which have only recently been discovered (H. socialis from mangrove habitats in Belize (Randall and Lobel 2003) and H. burekae from deep reefs in the Gulf of Mexico (Weaver and Rocha 2007)). In addition, the northern (coastal USA) population of H. bivittatus is genetically divergent and represents a cryptic species. The phylogeny of the genus is presently in flux and it is likely that it will be split into three, or perhaps many more, genera (there are numerous unrelated lineages in the Indo-Pacific). Most Caribbean species share a basic fin-ray count of D-IX,11 A-III,12 and Pect-13 (H. maculipinna and H. cyanocephalus have slightly differing fin-ray counts).
My DNA-sequence analysis reveals that there is a large clade of Atlantic Halichoeres made up of H. bivittatus, H. garnoti, H. poeyi, H. radiatus, and H. cyanocephalus (and its Brazilian sibling H. dimidiatus). There is a smaller related clade made up of H. pictus and H. socialis (along with the eastern Pacific H. dispilus and H. insularis). My results confirm that H. maculipinna falls out well away from the other Halichoeres and nearer to Thalassoma (Barber and Bellwood 2005).
The larvae of a number of Halichoeres overlap in appearance and DNA sequencing is necessary to confirm the species for those larvae. The species do become distinct as they develop juvenile markings. The size at settlement for this genus is quite consistent, around 10-12 mm (interestingly, one eastern Pacific sibling, H. insularis, settles much larger, up to 22 mm SL). An unusual aspect of the early life history of these labrids is that larvae undergoing transition are not captured in pelagic sampling, but are found buried in sand and rubble on reefs. This attribute is shared with Thalassoma bifasciatum, but not with Doratonotus megalepis or the related parrotfishes, both of which begin transition while still pelagic and transitional larvae are commonly caught in nearshore collections. Interestingly, I did collect one transitional larva of H. poeyi at a nightlight in Panama and it was the single largest Halichoeres larvae out of many hundreds collected, i.e. 13.8 mm SL.
Halichoeres bivittatus
 
Diagnosis: The fin-ray count of D-IX,11 A-III,12 and Pect-13 indicates Halichoeres and is shared by most of the Caribbean species. Larval H. bivittatus are identical to most other larval Halichoeres with five patches of median-fin melanophores and can only be identified by DNA sequencing.
Analogues:
Description: Body relatively thin, narrow and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide. Melanophores limited to the fin-ray membranes, typically occurring in five groups: at the front, mid, and rear dorsal fin and the front and rear anal fin. Each melanophore group covers from one to five fin spines or rays. Series of transitional larvae show development of the eye from vertically oval (and tilted backward) to round (round in many larvae captured over the reef).
Transitional recruits of H. bivittatus have a mid-dorsal fin ocellus and a mid-lateral body stripe extending directly rearward from the eye, present even in the earliest transitional stages. Transitional recruits on the reef commonly show remnants of the larval melanophores on the fin membranes.
Halichoeres bivittatus larva
10.8 mm SL
few melanophores
San Blas, Panama, SB81-118
larval slippery dick
Halichoeres bivittatus larva
11.9 mm SL
many melanophores
San Blas, Panama, SB81-023
larval Halichoeres bivittatus
Halichoeres bivittatus larva
10.3 mm SL
oval eye
San Blas, Panama, SB81-125
larval wrasse
Halichoeres radiatus
 
Diagnosis: The fin-ray count of D-IX,11 A-III,12 and Pect-13 indicates Halichoeres and is shared by most of the Caribbean species. Larval H. radiatus are identical to most other larval Halichoeres with five patches of median-fin melanophores and can only be identified by DNA sequencing.
Analogues:
Description: Body relatively thin, narrow and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide. Melanophores limited to the fin-ray membranes, typically occurring in five groups: at the front, mid, and rear dorsal fin and the front and rear anal fin. Each melanophore group covers from one to five fin spines or rays.
Transitional recruits have a mid-dorsal fin ocellus, a white-edged black spot on the upper base of the central caudal-fin rays and a patchy pattern of melanophores along the body with a mid-body bar extending from the dorsal ocellus down onto the anterior anal-fin rays.
Halichoeres radiatus transitional recruit
11.9 mm SL
San Blas, Panama, SB82-018
juvenile Halichoeres radiatus
Halichoeres garnoti
 
Diagnosis: The fin-ray count of D-IX,11 A-III,12 and Pect-13 indicates Halichoeres and is shared by most of the Caribbean species. Larval H. garnoti are identical to most other larval Halichoeres with five patches of median-fin melanophores and can only be identified by DNA sequencing.
Analogues:
Description: Body relatively thin, narrow and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide. Melanophores limited to the fin-ray membranes, typically occurring in five groups: at the front, mid, and rear dorsal fin and the front and rear anal fin. Each melanophore group covers from one to five fin spines or rays.
Transitional recruits of H. garnoti develop a mid-lateral body stripe from the lower half of the eye to the tail, extending onto the base of the caudal-fin rays. There is no dorsal fin ocellus. The stripe is iridescent blue against a bright yellow body in life; in preserved specimens the stripe is underlain with fine melanophores.
Halichoeres garnoti transitional recruit
12.7 mm SL
larval melanophore remnants
San Blas, Panama, SB80-105
juvenile Halichoeres garnoti
 
Halichoeres poeyi
 
Diagnosis: The fin-ray count of D-IX,11 A-III,12 and Pect-13 indicates Halichoeres and is shared by most of the Caribbean species. Larvae with a total of four patches of melanophores on the dorsal and anal fins (missing the anterior patch of dorsal fin melanophores) represent H. poeyi (confirmed by DNA sequencing).
Analogues:
Description: Body relatively thin, narrow, and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide. Melanophores on the fin-ray membranes typically occurring in in four groups: at the mid and rear dorsal fin and the forward and rear anal fin. Each melanophore group covers from one to five fin spines or rays. Most, but not all, larvae have a sub-surface melanophore at the top of the head behind the skull, sometimes two or three. Many of the larvae also have a small melanophore on the body at the ventral midline just after the last anal ray (often unnoticed adjacent to the large anal-fin membrane melanophores). Unlike other larval Halichoeres, this species has internal melanophores along the dorsal peritoneal cavity. The one transitional larva captured had begun to develop surface melanophores on the head.
Transitional recruits of H. poeyi have a mid-dorsal fin ocellus, a spot on the caudal peduncle just behind the base of the last dorsal ray, a white-edged black spot on the upper base of the central caudal-fin rays, a chain-link patch pattern along the lateral midline, and colored striping on the top of the head. Some variants lack the chain-link pattern and have melanophores uniformly covering the upper and lower sides of the body with a mid-lateral band with no melanophores. Transitional recruits on the reef commonly retain the larval melanophores behind the skull and remnants of the larval melanophores on the fin membranes.
Halichoeres poeyi larva
12.6 mm SL
San Blas, Panama, SB86-331
larval Halichoeres poeyi
Halichoeres poeyi larva
12.5 mm SL
dorsal peritoneal melanophores
San Blas, Panama, SB80-102
larval wrasse
Halichoeres poeyi transitional larva
13.8 mm SL
head melanophores
San Blas, Panama, SB80-102
larval blackear wrasse
  larval labrid
Halichoeres poeyi early transitional recruit
11.1 mm SL
San Blas, Panama, SB83-137
blackear wrasse juvenile
Halichoeres poeyi early transitional recruit
11.6 mm SL
San Blas, Panama, SB83-148
juvenile Halichoeres poeyi
Halichoeres pictus
 
Diagnosis: The fin-ray count of D-IX,11 A-III,12 and Pect-13 indicates Halichoeres and is shared by most of the Caribbean species.
Analogues:
Description: Body relatively thin, narrow and long with a large eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and relatively wide.
Halichoeres radiatus transitional recruit
11.9 mm SL
San Blas, Panama, SB82-018
 
Halichoeres maculipinna
Diagnosis: The fin-ray count of D-IX,11 A-III,11 and Pect-14 indicates Halichoeres maculipinna. This species has one fewer anal-fin ray than the other Halichoeres in the region and both larvae and recruits have a different morphology, appearing wider and thicker-bodied.
Analogues:
Description: Body relatively thin, wide and long with a medium eye and a terminal, small mouth. Pectoral fins medium, reach to vent. Pelvic fins very short. Dorsal and anal-fin bases long, caudal peduncle short and wide. Melanophores limited to the fin-ray membranes, typically on the last few dorsal-fin rays and a matching group on the last anal-fin rays. Each melanophore group covers from three to five fin rays.
Transitional recruits of H. maculipinna show more variable markings than other labrids. Those individuals in grassbeds are uniformly green, while those on reefs have a distinct black stripe along the side of the body.
Halichoeres maculipinna larva
12.7 mm SL
Barbados, coll. by Henri Valles
larval Halichoeres maculipinna
Xyrichtys martinicensis
Diagnosis: The fin-ray count of D-IX,12 A-III,12 and Pect-12 indicates the razorfish genus Xyrichtys. One other regional labrid, Halichoeres cyanocephalus, shares the median-fin ray count, but has 13 pectoral-fin rays and a clearly different body shape. The three Caribbean razorfishes, X. martinicensis, X. novacula, and X. splendens, share fin-ray counts and the larvae can overlap in appearance. The species become distinct as they develop juvenile markings: X. martinicensis recruits are recognized by a simple lateral stripe from the eye to the tail that is not broken up into patches or spots.
Analogues: Larval Xyrichtys have no melanophores and often markedly-narrowed eyes. The absence of external melanophores is shared with larval Doratonotus megalepis, which are distinctly wider-bodied and have large round eyes. All other regional labrid and scarid larvae have melanophores. X. martinicensis recruits have a simple lateral stripe from the eye to the tail while X. novacula recruits have a stripe that is broken up into discrete patches or spots. X. splendens recruits develop a complex pattern of bars and reticulations. X. martinicensis recruits also do not display the extended first dorsal fin spines characteristic of the juveniles of the other two razorfish species.
Description: Body thin and long with a markedly narrowed eye (pre-transitional) to large and round (recruits) with a pointed snout and a terminal small mouth. Pectoral fins medium, reach to vent. Pelvic fins stubs. Dorsal and anal-fin bases long, caudal peduncle short. There are no surface or internal melanophores.
Transitional recruits show a dark stripe of fine melanophores curving up from the eye across the upper body onto the base of the upper caudal-fin segmented rays. There is a lighter band beneath the stripe ending in a white patch at the base of the central caudal-fin rays.
Xyrichtys martinicensis recruit
13.0 mm SL
San Blas, Panama, SB82-098
larval Xyrichtys martinicensis
Xyrichtys splendens
Diagnosis: The fin-ray count of D-IX,12 A-III,12 and Pect-12 indicates the razorfish genus Xyrichtys. One other regional labrid, Halichoeres cyanocephalus, shares the median-fin ray count, but has 13 pectoral-fin rays and a clearly different body shape. The three Caribbean razorfishes, X. martinicensis, X. novacula, and X. splendens, share fin-ray counts and the larvae can overlap in appearance. The species become distinct as they develop juvenile markings: X. splendens recruits are recognized by a pattern of bars and reticulations and the first two dorsal fin spines are extended. The extended dorsal fin spines persist until juveniles reach about 35 mm SL.
Analogues: Larval Xyrichtys have no melanophores and often markedly-narrowed eyes. The absence of external melanophores is shared with larval Doratonotus megalepis, which are distinctly wider-bodied and have large round eyes. All other regional labrid and scarid larvae have melanophores. X. splendens recruits have a a complex pattern of bars and reticulations and the extended first two dorsal fin spines while X. martinicensis recruits have a lateral stripe from the eye to the tail and no extension of the dorsal fin spines and X. novacula recruits have a lateral stripe that is broken up into discrete patches or spots.
Description: Body thin and long with a markedly narrowed eye (pre-transitional) to large and round (recruits) with a pointed snout and a terminal small mouth. Pectoral fins medium, reach to vent. Pelvic fins stubs. Dorsal and anal-fin bases long, caudal peduncle short. There are no surface or internal melanophores.
Transitional recruits show a pattern of bars and reticulations and the first two dorsal-fin spines are extended.
Xyrichtys martinicensis recruit
13.0 mm SL
San Blas, Panama, SB82-098
 
Xyrichtys novacula
Diagnosis: The fin-ray count of D-IX,12 A-III,12 and Pect-12 indicates the razorfish genus Xyrichtys. One other regional labrid, Halichoeres cyanocephalus, shares the median-fin ray count, but has 13 pectoral-fin rays and a clearly different body shape. The three Caribbean razorfishes, X. martinicensis, X. novacula, and X. splendens, share fin-ray counts and the larvae overlap in appearance. The species become distinct as they develop juvenile markings: X. novacula recruits are recognized by lateral stripe broken up into patches or spots and the first two dorsal fin spines are extended. The extended dorsal fin spines persist until juveniles reach about 25 mm SL.
Analogues: Larval Xyrichtys have no melanophores and often markedly-narrowed eyes. The absence of external melanophores is shared with larval Doratonotus megalepis, which are distinctly wider-bodied and have large round eyes. All other regional labrid and scarid larvae have melanophores. X. novacula recruits have a lateral stripe broken up into patches or spots and the first two dorsal fin spines are extended while X. martinicensis recruits have an intact stripe and no extended first dorsal fin spines. X. splendens recruits develop a complex pattern of bars and reticulations.
Description: Body thin and long with a markedly narrowed eye (pre-transitional) to large and round (recruits) with a pointed snout and a terminal small mouth. Pectoral fins medium, reach to vent. Pelvic fins stubs. Dorsal and anal-fin bases long, caudal peduncle short. There are no surface or internal melanophores.
Transitional recruits show a lateral stripe broken up into patches or spots and the first two dorsal-fin spines are extended.
Xyrichtys martinicensis recruit
13.0 mm SL
San Blas, Panama, SB82-098
 
Doratonotus megalepis
Diagnosis: The fin-ray count of D-IX,10 A-III,9 with only 11 or 12 pectoral-fin rays indicates Doratonotus megalepis. Caribbean parrotfishes (family Scaridae) share the median-fin ray count, but have 13-16 pectoral-fin rays. (U)
Analogues:
Description: Body relatively thin, short and wide with a large eye and a terminal, small mouth. Pectoral and pelvic fins short. Dorsal and anal-fin bases relatively long, caudal peduncle short and wide. The only melanophores are internal on the dorsal peritoneal lining, usually one or two. Series of transitional larvae show development of the eye from flat and round with a large pupil to somewhat bulbous with a small pupil. Transitional larvae develop narrow bars of tiny melanophores radiating out from the eye as well as a broad iridophore bar from the eye across the lower operculum. Small melanophores develop on the first two dorsal spine membranes and along the pelvic-fin membranes.
Doratonotus megalepis larva
6.9 mm SL
San Blas, Panama, SB86-413
larval Doratonotus megalepis
Doratonotus megalepis larva
7.0 mm SL
San Blas, Panama, SB86-415
larval dwarf wrasse
Doratonotus megalepis larvae
6.6, 6.7, and 6.8 mm SL
variation in # of internal melanophores
San Blas, Panama, SB84-523
labrid larvae
Doratonotus megalepis transitional larva
6.2 mm SL
San Blas, Panama, SB84-520
larval wrasse
  larval Doratonotus megalepis
  early life history wrasse
Doratonotus megalepis transitional larva
6.2 mm SL
eye changes with small pupil
San Blas, Panama, SB86-413
larval wrasse
Decodon puellaris
Diagnosis: The fin-ray count of D-XI,10 A-III,10 indicates Decodon puellaris. I have not identified larvae of D. puellaris in my collections, but larvae corresponding to the eastern Pacific sibling species, D. melasma, share the fin-ray count and are likely similar.
Analogues:
Description:
Clepticus parrae
 
Diagnosis: The fin-ray count of D-XII,10 A-III,12 and Pect-17 indicates Clepticus parrae. Bodianus share the median-fin ray count, but have one fewer pectoral-fin ray and a different body shape. (U)
Analogues:
Description:
 
 
Bodianus rufus
Diagnosis: The fin-ray count of D-XII,10 A-III,12 and Pect-16 indicates Bodianus. Clepticus parrae shares the median-fin ray count but has one more pectoral-fin ray and a different body shape. The two Caribbean Bodianus spp. share their fin-ray counts, but B. rufus is far more common than the deep-water species B. pulchellus (although the latter cannot be excluded for the pre-transitional larval stages). B. rufus larvae develop into a bicolored recruit with the anterior lower-half dark blue and the rear and upper-half yellow (in contrast to adults where it switches to the anterior upper-half blue). Recruits of B. pulchellus are uniformly yellow. (U)
Analogues: Larval Thalassoma bifasciatum can appear similar but have a narrower body, smaller eye, and the dorsal-fin origin is distinctly forward on the body.
Description: Body relatively thin, long and wide with a large eye and a terminal, pointed, small mouth. Pectoral fins medium length. Pelvic fins short. Dorsal and anal-fin bases relatively long, caudal peduncle short and wide.
Bodianus rufus recruit
10.1 mm SL
San Blas, Panama, SB81-077
larval Bodianus rufus
  larval spanish hogfish
Lachnolaimus maximus
Diagnosis: The fin-ray count of D-XIV,11 A-III,10 indicates Lachnolaimus maximus. I have not collected this species, but Colin (1982) raised the larvae through their larval phase. The larvae resemble Doratonotus megalepis in basic form, but develop surface melanophores early in development, around the time the fin rays are fully formed (about 5 mm SL). This feature is particularly unusual for labrids (or other labroids) and it is likely that this species is the sole member of the family to have body pigmentation (none of the Indo-Pacific labroid larvae identified by Leis and Carson-Ewart (2000) have this character). The adaptation suggests that larval L. maximus are associated with drift algae and not exposed in the plankton.
Analogues: In most features this larval type resembles larval Doratonotus megalepis, but is distinguished by a slightly different fin-ray count and, most conspicuously, by having extensive melanophore patterns on the body. The arrangement of melanophores on the head resembles that of transitional D. megalepis and they share the markings on the first dorsal-fin spines and pelvic fins, but even late transitional D. megalepis do not have the reticulated patterns on the body.
Description: Body relatively thin, short and wide with a large eye and a terminal, small mouth. Pectoral and pelvic fins short. Dorsal and anal-fin bases relatively long, caudal peduncle short and wide. By the time the fin-ray complement has formed, around 5.5 mm SL, melanophores are scattered over the body and in three discrete patches along the anal-fin base. Subsequently, melanophores develop in bars radiating from the eye: forward across the jaw, a vertical below the eye, and in bands across the top of the head. A reticulated pattern of melanophores then develops over the body. Since the larvae were raised in captivity, the point of transition cannot be determined. Series of larvae shows the eye remains round.
 

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