Hypoplectrus affinis Poey, 1868

Puebla, Oscar, Coulmance, Floriane, Estapé, Carlos J., Estapé, Allison Morgan & Robertson, D. Ross, 2022, A review of 263 years of taxonomic research on Hypoplectrus (Perciformes: Serranidae), with a redescription of Hypoplectrus affinis (Poey, 1861), Zootaxa 5093 (2), pp. 101-141 : 118-124

Hypoplectrus affinis Poey, 1868

Common names: English: bluelip hamlet

Spanish: vaca de labios azules

French: hamlet à lèvres bleues

Fig. 3 ; Tables 2 , 3

Plectropoma affine Poey 1861:427 (type locality Cuba)

Hypoplectrus chlorurus Poey 1868:290 ; Guitart 1977:361; Domeier 1994:105

Hypoplectrus puella var. affinis Jordan & Eigenman 1890:385

Hypoplectrus unicolor affinis Jordan & Evermann 1896:1193

Neotype. STRI 18986, 81.2 mm SL, Punta Juan , Isla Cristóbal, Bocas del Toro, Panama (9º17’54”N 82º17’22”W), 8.5 m depth, March 25 2005, reef, microspear, O. Puebla and B. Holt (ERS8632037).

Additional material. STRI 19174, 75.7 mm SL, Cayos Holandeses , Guna Yala, Panama (9º34’49”N 78º41’39”W), 8.5 m depth, May 7 2005, reef, microspear, O. Puebla and A. Castillo. STRI 19293, 90.5 mm SL, Cayos Holandeses, Guna Yala, Panama (9º34’35”N 78º43’45”W), 12 m depth, May 22 2005, reef, microspear, O. Puebla and D. Roche. STRI 19294, 83.3 mm SL, Cayos Holandeses, Guna Yala, Panama (9º34’35”N 78º43’45”W), 12 m depth, May 22 2005, reef, microspear, O. Puebla and D. Roche. STRI 19519, 75.6 mm SL, Cayos Ingleses, Guna Yala, Panama (9º17’27”N 78º8’25”W), 6 m depth, May 14 2005, reef, microspear .

Diagnosis. Hypoplectrus affinis is distinguished from all named congeners by colouration. The body and dorsal fin are brown, without dark vertical bars, the pelvic fins are bright smoky blue and anal fin ranges from smokyblue to brown with smoky blue tones ( Figure 3 ). The lips are smoky blue and the iris is yellow. The most similarly coloured, unbarred hamlets are H. randallorum , H. chlorurus , H. nigricans and H. atlahua , which differ most from H. affinis in the ground colour of the body: lighter (tan) in H. randallorum (which also has large dark spots on the caudal peduncle and snout) and darker (black) in H. chlorurus , H. nigricans and H. atlahua (plus H. chlorurus has yellow pectoral and caudal fins).

Description. The morphometric measurements and meristic counts of the neotype and additional material are presented in Table 2 . Dorsal X, 15; anal III, 7; pelvic I, 5; pectoral rays 13; mouth terminal. Morphometrics as percentage SL (mean, min–max): body depth 39.8% SL (37.3–43.9); body compressed, width 15.6 (13.5–18.2); head length 36.4 (34.9–38.7); snout length 11.6 (10.3–13.3); orbit diameter 8.7 (8.6–8.8); interorbital width 8.7 (8.4–9.2); upper jaw length 15.9 (14.7–17.0); caudal–peduncle depth 13.6 (13.0–14.1); caudal–peduncle length 11.4 (10.6–12.2); predorsal length 36.4 (35.0–38.5); prepelvic length 36.9 (35.4–38.9); prepectoral length 34.7 (32.6– 37.0); base of dorsal fin 51.4 (49.0–54.3); base of anal fin 16.7 (15.4–18.1); longest dorsal spine 14.6 (13.6–15.6); longest anal spine 14.0 (13.3–14.6); longest anal ray 17.1 (16.1–18.8); caudal fin length 23.6 (20.4–25.5); pectoral fin length 29.5 (27.9–31.3); pelvic fin length 23.9 (22.5–25.1). Morphometrics as percentage HL (mean, min–max): snout length 31.9 (28.5–34.5); upper jaw length 43.8 (38.0–47.2) interorbital width (24.0, 21.8–26.5); orbit diameter (24.0, 22.4–25.4). Body moderately deep, caudal fin truncate, pelvic fins elongate ovals with rounded tips.

A detailed summary of the morphological characteristics that are common to all Hypoplectrus species is provided in Lobel (2011). This summary is repeated here for completeness with minor modifications relevant to H. affinis : body deep, compressed, depth 2.1–2.7 times in SL. Head pointed, forehead oblique and straight, large fish with a low hump on rear of nape; nostrils closer to eye than jaw. Mouth large, oblique, opens slightly above midline, lower jaw slightly projecting, reaches under about center of eye, upper jaw moderately protrusile; supramaxilla absent, posterior process of premaxilla broad and near tip of alveolar ramus. Jaw teeth fixed (not depressible), distinct, small canines; vomer and palatines with villiform teeth arranged in rows. Preopercle angular, not expanded posteriorly, with serrae along ventral and posterior margins and several small antrorse serrae on ventral margin near angle. Branchiostegal rays 7; gill rakers on first arch moderately long and slender, 6–8 on upper limb and 11–15 on lower limb. Dorsal fin X, 14–16, interspinous fin membranes not incised or notched; no elongate dorsal spines; anal fin III, 7; pectoral fins elongated and rounded; pelvic fins with rounded blunt tips, reaching to or beyond anus but not relatively elongate; caudal fin truncate. Scales ctenoid, cover all body and head, except snout and preorbital region naked; no scaly flap of skin joining upper part of pectoral base to body; soft dorsal and anal fins mostly naked. Vertebrae 10 + 14; lateral-line gradually arched anteriorly, with 48–54 pored scales.

Live colouration ( Figure 3 ). The ground colour of the head and body ranges from grey-brown to yellowishbrown to reddish-brown to greenish-brown, typically with the lower half of the body darker than the upper half, often with a broad darker zone along the mid-flank; a faint pale bar under the eye occasionally present; the large iris is bright yellow to orange-yellow; the lips are smoky blue, colour that extends along the ventral body profile to the origin of the anal fin, and sometimes up onto the flank; the dorsal fin varies from the same colour as the upper body to paler, with a thin bluish line along the outer margin, often with an area of dense fine blue-grey lines running obliquely across the soft dorsal; caudal fin translucent brown to yellowish-brown, to grey-brown, with thin dark upper and lower margins; the pectoral fins are translucent, with a small dark spot at the upper corner of the fin base and a thin dark line along the upper fin margin; the pelvic fins are bright smoky blue; the anal fin ranges from bright smoky blue to brown with smoky blue tones, with a thin blue line along the outer margin. Juveniles and small adults have similar colours to adults, but with less developed blue coloration on the pelvic and anal fins and lower body profile, and sometimes, as in juveniles of other hamlets, with a dark spot at the upper rear corner of the caudal peduncle. Courting and spawning adults have more blanched colors than outside the reproductive period.

Colouration in preservation. Uniformly light brown.

Comparisons. Hypoplectrus affinis is distinguished from most of its congeners by colouration. The most similarly coloured species are H. randallorum , H. chlorurus , H. nigricans and H. atlahua , from which H. affinis differs by the colour of the body: lighter (tan) in H. randallorum and darker (black) in H. chlorurus , H. nigricans and H. atlahua (plus H. chlorurus has yellow pectoral and caudal fins). The range of morphometric measurements and meristic counts of the H. affinis neotype and other specimens versus H. puella (n = 5), H. nigricans (n = 5), H. unicolor (n = 5), H. aberrans (n = 5), H. indigo (n = 5) and H. guttavarius (n = 1) are presented in Table 3 : as for the other hamlet species (except H. gemma and H. atlahua ), these measurements and counts largely overlap. Hypoplectrus affinis has body and fin shapes and sizes similar to the great majority (but not all) of its congeners. The exceptions to that pattern, which have semilunate caudal fins and vary in body depth and in the size and form of the pelvic fins are H. gemma and a “black” hamlet from the northeastern Caribbean (see below).

Taxonomic remarks. This species was originally described from Cuba in an addendum published on the last page of the second tome of Poey’s Memorias sobre la historia natural de la Isla de Cuba ( Poey 1861, p. 427). Poey first mentioned that this species is close to H. nigricans ( Poey 1861) , then made it a variety of H. chlorurus ( Poey 1868, p. 290) , and finally considered it a distinct species which he renamed Hypoplectrus affinis ( Poey 1875, p. 98) . Poey maintained this position in his Ictiología Cubana, finalized in 1883 and published post-mortem in 2000, where H. affinis was described as a separate species in a very brief description focused on its colour pattern ( Poey 2000b, p. 90). The type specimens of the original description have been lost. Hypoplectrus affinis was later synonymized with H. chlorurus by Guitart (1977) and Domeier (1994). It is not clear on what basis though since Cuvier’s original description of H. chlorurus described a black fish with a yellow tail and yellow pectoral fins. Fischer (1980a) briefly described the coloration of this species, which he observed in Jamaica and Panama (Guna Yala and Bocas del Toro) And named it the “bluelip” hamlet.

The original H. affinis type specimens were searched for at the Museo Poey and Museo Nacional de Historia Natural in Cuba, as well as the Harvard Museum of Comparative Zoology where some of Poey’s type specimens were sent. The type specimens of H. pinnivaria and H. guttavarium (both now H. guttavarius ), P. nigricans (now H. nigricans ), P. bovinum (now H. indigo ) and H. maculiferus were found. However, the curators of those museums did not find the types of H. affinis and consider them lost. Hypoplectrus affinis is therefore redescribed here based on specimens from Panama and photographs from a variety of locations.

Etymology. The binomial name Hypoplectrus affinis , given by Poey (1875), refers to the fact that this species is related but not identical to H. nigricans and H. chlorurus (today this also applies to H. atlahua and H. randallorum , which were not described at the time). The English common name bluelip hamlet, given by Fischer (1980a), refers to the smoky blue colour of the lips. The Spanish name vaca de labios azules and the French name hamlet à lèvres bleues are direct translations of bluelips, in combination with the common name that is most commonly used for the hamlets in Spanish (vaca) and in French (hamlet).

Behaviour. The small number of individuals observed in Bocas del Toro ( Panama) indicate that like the other hamlets, H. affinis is diurnal and solitary, although individuals are sometimes observed in pairs. These observations also indicate that, at Bocas del Toro at least, H. affinis is non-territorial and extremely mobile, continuously swimming over a large section of the reef, to the point that it requires all the observer’s attention to not lose track of it. Like the other hamlets, H. affinis spawns at dusk in pairs. In Bocas del Toro, H. affinis pairs assortatively (i.e. with members of the same species) notwithstanding the fact that it is extremely rare (n = 2 observations). Assortative pairing and spawning has also been observed in Grand Cayman ( Figure 3 ). Individuals at Bocas del Toro sometimes travel long distances (hundreds of meters) to find conspecific mates, which may be due to the fact that H. affinis is rare there.

Ecology. Like the other hamlets, H. affinis is reef-associated. Its foraging behaviour suggests that like the other hamlets, H. affinis is a mesopredator. In Bocas del Toro and Guna Yala ( Panama), it has been observed at depths ranging from 2 to 12 m.

Geographic distribution. Hypoplectrus affinis is not endemic to Panama. Poey’s original description was from the north coast of Cuba, Fisher (1980a) reported it in Jamaica and Panama (Guna Yala and Bocas del Toro), and we herein redescribe it from specimens collected in Panama. Photographs or videos of individuals corresponding to the description of H. affinis from Nicaragua (Corn Islands), Mexico (Alacranes reef, Campeche Bank), the Florida Keys, Grand Cayman, the Dominican Republic (Sosua Bay on the north coast), Los Roques ( Venezuela), Bonaire and Tobago have been validated by DRR and OP. Five other valid species of Hypoplectrus described by Poey from specimens collected in northern Cuba are known from the Florida Keys, the closest non-Cuban site to the original type locality for H. affinis , from which it is separated by the 150 km wide Straits of Florida. This indicates that Poey’s species often occur in the Florida Keys as well as Cuba, and supports the notion that, in the absence of photographs from northern Cuba, H. affinis also has such a distribution.

Figures

FIGURE 3. Hypoplectrus affinis (Poey, 1861). a. neotype, STRI 18986, 81.2 mm SL, Punta Juan, Isla Cristóbal, Bocas del Toro, Panama (9º17’54”N 82º17’22”W), 8.5 m depth, March 25 2005, reef, OP and B. Holt b. STRI 19174, 75.7 mm SL, Cayos Holandeses, Guna Yala, Panama (9º34’49”N 78º41’39”W), 8.5 m depth, May 7 2005, reef, OP andA. Castillo c. Panama (Bocas del Toro, not collected) d. Mexico (Alacran reef, Campeche) e. & f. (juvenile) Florida Keys g. Grand Cayman (spawning pair, note blanched coloration) h. Bonaire (note that a similar fish was photographed by AME in Dry Tortugas). Photographs a, b and c by OP, d by Isai Dominguez Guerrero, e and f by CJE and AME, g by Frank Krasovec and h by Kim White, all with permission.