Serranus pulcher Wirtz and Iwamoto, 2016

Wirtz, Peter & Iwamoto, Tomio, 2016, A New Species of Serranus from São Tomé and Príncipe, Eastern Atlantic (Pisces Teleostei, Serranidae), Proceedings of the California Academy of Sciences 63 (6), pp. 191-200 : 192-199

Serranus pulcher Wirtz and Iwamoto , sp. nov.

Figures 1–9 , Tables 1–5 .

Serranus sp. (“ São Tomé comber“), Debelius 1998: 148. Kuiter 2004:162, figs. A-D.

Serranus n.sp., Wirtz et al. 2007:8–9 , fig. 8

MATERIAL EXAMINED.— Holotype: ZSM 43868 (59 mm SL), São Tomé Island (00º25.099ʹN, 006º41.718ʹE), near wreck “Mar Vassa“ on coral rubble in about 6 m depth, Jan. 2015, formol preserved, coll. Nuno Vasco Rodrigues. A small piece of the left pectoral fin is missing and the dorsal fin is slightly torn between the spinous and the soft-rayed part (figure 1a and b) . Paratypes measured: ZSM 43869 (66 mm SL) same data as holotype. ZSM 43879 “Mar Vassa”, São Tomé Island (00º25.099ʹN, 006º41.718ʹE), Nov. 2014, coll. Nuno Vasco Rodrigues. ZSM 43880 “Mar Vassa”, São Tomé Island (00º25.099ʹN, 006º41.718ʹE), Mar. 2014, coll. Nuno Vasco Rodrigues. CAS227751 (70.5 mm SL), São Tomé Island, Kia Reef (00º25ʹ0.01ʺN, 006º48ʹE), 25–40 ft [7.6– 12.2 m], 11 Jan. 2009, coll. J.E. McCosker, D. Catania, and J.-L. Testori. CAS227753 (73 mm SL, specimen labelled DC1009), Príncipe Island (01º41ʹ09.3ʺN, 007º28ʹ07.6ʺE), 40 ft [12.2 m], 23 Jan. 2009; coll. J.E. McCosker and D. Catania. CAS 227754 (4 spec., 45–74 mm SL), Príncipe Island, nw side Bom Bom Is. (01º41ʹ44.0ʺN, 007º24ʹ00.3ʺE), 48 ft [14.6 m], 20 Jan. 2009, coll. J.E. McCosker and D. Catania. CAS227755 (1 spec.), São Tomé Island, Kia Reef (00º21ʹ37.1ʺN, 006º43ʹ08.5ʺE), 45–72 ft [13.7–21.9 m], 11 Jan. 2009, coll. J.E. McCosker, D. Catania, and J.-L. Testori. CAS227756 (2 spec., 75–78 mm SL), São Tomé Island, Batalleo (00º22ʹ05.7ʺN, 006º45ʹ41.6ʺE), 13 Jan. 2009, coll. J.E. McCosker, D. Catania, and E. Milson. CAS227757 (specimen labelled DC999), Príncipe Island, Pedro Adalia (01º42ʹ04.0ʺN, 007º25ʹ42.1ʺE), 21 Jan. 2009, coll. J.E. McCosker, D. Catania, and R. Van Syoc . Paratypes not measured: CAS227752 (7 juveniles), Príncipe Island, Pedro Adalia (01º42ʹ02.3ʺN, 007º25ʹ43.8ʺE), 52 ft [15.8 m], 19 Jan. 2009, coll. J.E. McCosker and D. Catania. CAS227757 (8 juveniles), Príncipe Island, Pedro Adalia (01º42ʹ04.0ʺN, 007º25ʹ42.1ʺE), 21 Jan. 2009, coll. J.E. McCosker, D. Catania, and R. Van Syoc. CAS227758 (3 spec.), Príncipe Island, Isla Santana, cave (00º14ʹ33.1ʺN, 006º45ʹ36.1ʺE), 62 ft [18.9 m], 28 Jan. 2009, coll. J.E. McCosker, and J.-L. Testori. CIUFES 150 (pectoral fin taken for DNA sample), São Tomé Island; CIUFES 155 (4 spec.), São Tomé Island; ZSM uncatalogued (3 juvenile spec., tissue samples taken for DNA analysis), Príncipe Island.

a

DIAGNOSIS.— Dorsal rays X,12; dorsal fin notched between spinous and soft part; anal rays III,7; pectoral rays usually 15 (rarely 14 or 16); pelvic rays I,5; gill rakers 6–9+12–14 (19– 23 total); pored lateral-line scales 42–49; circumpeduncular scales 20–25, usually 22–24; interorbital without scales. Caudal fin truncate, the upper lobe slightly produced, lower lobe rounded. Dorsal, anal, and pectoral fins scaly near base. Scales ctenoid, not deciduous; 5–6 rows of scales from the beginning of the dorsal fin to the lateral line; three opercular spines, the middle one largest, the upper one often obscure, the lower one sometimes invisible to the naked eye; rear margin of anterior nostril forming a flap usually fringed with 4–6 long cirri that reach well past the rear nostril; posterior nostril a simple opening lacking a raised rim. Lips red with dark bands; a short moustache-like red streak behind end of maxillary, running across hind margin of dentary and almost meeting opposite streak at midventral line and enclosing ivory-white of mandibular rami; another red diagonal streak running from upper edge of maxillary, across lower edge of preopercle, across interopercle and branchiostegal rays, to base of pelvic fin, and enclosing white of preopercle, interopercle and chest. Size to at least 9 cm total length.

DESCRIPTION.— Measurements and counts are presented in tables 1–5. Body relatively slender and compressed, width over pectoral bases about half of HL, greatest body depth about 2.7– 3.2 in SL and less than HL, which is about 2.4– 2.6 in SL. Dorsal and ventral profiles gently curved from tip of snout to caudal fin. Snout shorter in length than orbit diameter; both substantially more than interorbital width. Lower jaw projecting slightly beyond upper jaw; maxilla extending to below posterior half of pupil. Preopercle margin serrated with flattened spines, those at angle largest. Mouth large with upper jaw reaching to the level of the rear edge of the eye or beyond. Premaxillary teeth in a narrow band, the outer series spaced and slightly enlarged; one or more large canines at anterior end. Dentary with a band of small teeth flanked by a series of slightly enlarged outer teeth that become larger posteriorly. Vomerine tooth band broadly V-shaped, followed on each arm by narrow band of small palatine teeth.

Dorsal rays X,12; first 4–5 spines of dorsal fin graduated, the 3rd to 5th spines longest, the spines following subequal; the soft rays slightly higher than longest spines, the 3rd to 5th ray longest; a slight notch in fin profile. Anal rays III,7; anal fin relatively high, its posterior tip somewhat pointed; spines shorter than soft rays, the first spine more than half length of second and third spines, the second spine longer and stouter than the others. Pectoral 14–16, usually 15 soft rays; pectoral fin broad-based, its origin about on same vertical as those of dorsal and pelvic fins; the tip of pectoral fin extends to, or almost to, anus.

Pelvic rays I,5; the distal tips of the soft rays sometimes reach the level of the anus but often they are shorter. Caudal fin with usually 15 (one specimen with 17) branched rays; caudal fin truncate; dorsal lobe slightly produced, ventral lobe rounded at tip (Fig 2). Lateral line slightly arched over pectoral fin and from there on parallel to dorsal profile. Scales on the nape from the beginning of the dorsal fin forward to the level of the serrated edge of the preoperculum, but not further forward (i.e., interorbital without scales); scales present on operculum (7 oblique rows of scales) and preoperculum (6 rows), but absent in all areas in front of eyes; six branchiostegal rays. Rear margin of anterior nostril forming a flap usually fringed with five (rarely four or six) finger-like cirri that reach well past the rear nostril; rear nostril a round hole without raised rim.

Counts and measurements of the holotype and paratypes in the ZSM collection are given in Table 1 and those of some specimens in the CAS collection in Table 2 . Additional counts and measurements on further specimens in the CAS collection are given in Table 3 . Counts and measurements taken by Phil Heemstra ( SAIB) on 6 specimens from São Tomé and Príncipe, collected by P. Wirtz in 2004, are given in Table 4 ; these specimens apparently are lost now.

Counts and measurements on 5 specimens from São Tomé Island taken by Francisco Reiner are given in Table 5 ; these specimens are apparently now lost.

The paratype ZSM 43879 was dissected and turned out to have the genus-typical (Erisman and Hastings 2011) hermaphroditic gonad: the ovotestis is dominated by ovarian tissue with testicular tissue restricted to the posterior and ventral part.

Color in alcohol ( Fig. 1a ): Alternating light and dark areas on upper and lower lip; head and upper half of body light brown; some lighter blotches on rear half of lower body; belly light; no dark spots on snout and fin membrane between the first two dorsal spines not black.

Color in vivo: Color extremely variable ( Figs. 2–9 ). The following patterns appear to be most common: lips red to orange with dark bands; a short moustache-like streak behind end of maxillary, running across hind margin of dentary and almost meeting opposite streak at midventral line and enclosing ivory-white of mandibular rami; another diagonal streak running from upper edge of maxillary, across lower edge of preopercle, across interopercle and branchiostegal rays, to base of pelvic fin, and enclosing white of preopercle, interopercle and chest ( Fig. 8 ); first rays of pelvic fins white. Juveniles can have orange, white, and dark stripes ( Fig. 9 ).

HABITAT AND DISTRIBUTION.— On hard bottoms (rock, gravel, coral rubble, or maerl) from about 1 m (juveniles) to at least 30 m depth. The new species is currently known with certainty only from the islands of São Tomé and Príncipe, where it is apparently common in suitable habitats (Luiz Rocha and John McCosker, CAS, personal communication). If the DNA analyses of an aquarium specimen taken off Ghana (Figs. 10–11) show that specimen to be the same as S. pulcher , the new species is also present on the mainland coast of Africa in the Gulf of Guinea.

COMPARISON WITH OTHER EASTERN ATLANTIC SPECIES OF SERRANUS .— The species most similar in morphology to Serranus pulcher is heterurus Cadenat, 1937 . The two species share the name-giving feature of S. heterurus , i.e. the upper lobe of the caudal fin is pointed and the lower lobe of the caudal fin is rounded (also the case in several western Atlantic Serranus species). Serranus pulcher and heterurus are the two smallest of the eastern Atlantic Serranus species. Serranus pulcher differs from all others except heterurus in a combination of the following characters (see also Table 6 ): dorsal fin X, 12; anal fin III, 7; 42–50 lateral-line scales; interorbital area without scales; upper lobe of caudal fin pointed, lower lobe of caudal fin rounded.

FIGURE 11. Serranus sp. from Ghana (photo Joe Russo).

The values of all morphological variables measured in nine specimens of heterurus (i.e., those mentioned in the description of S. pulcher , above) overlapped with those of pulcher . The two species differ in live color: heterurus has seven narrow white bars along a wine-red body, the first one on the opercle, the last one directly before the tail fin, a crescent-shaped light blue or white mark directly behind the eye and small blue spots on head and vertical fins ( Figs. 12 –14). In alcohol-preserved specimens of heterurus ( Fig. 15 ) the white bars are often still visible, the area between the tip of the snout and the eyes bears dark spots, and the upper margin of the fin membrane between the first dorsal spines is often blackish; the crescent-shaped mark directly behind the eyes is often still visible but brown.

ETYMOLOGY.— pulcher, Latin , meaning beautiful.

PROPOSED ENGLISH COMMON NAME.— São Tomé Comber.

REMARKS.— In the aquarium literature, Hemdal (2009) described and figured a Serranus species from the coast of Ghana called “Peppermint basslet”. It is similar to S. pulcher (compare Figs. 10 and 11) and almost certainly belongs to the same species. A tissue sample from a specimen collected for the aquarium trade at Ningo, east of Tema harbour in Ghana, at about 12 m depth (05°41.177ʹN, 000°17.510ʹE) will be analysed for its DNA sequence.

Many years ago, the first author sent specimens and photographs of the new species to Phil Heemstra ( SAIB), who agreed to describe it. But after several years during which he apparently made no progress on the description, Heemstra agreed to send all the specimens back. In the ensuing years, as collecting efforts using SCUBA on the islands of São Tomé and Príncipe became more common (see Afonso et al. 1999 and Wirtz et al. 2007), many more specimens of the new species became available. The species was, in fact, discovered to be quite common in coastal waters of the islands. It also appeared to be a species taken by aquarium collectors on the mainland coast of Africa off Ghana, although the identity of fish from that country has yet to be confirmed. Because we are finalizing a manuscript reviewing all eastern Atlantic members of the genus (Wirtz, Heemstra, and Iwamoto, in prep.), and because the species is common and frequently observed on the islands, we felt it necessary for us to provide a name and description of the species.

Figures

FIGURE 1. Holotype of Serranus pulcher sp. nov. ZSM 43868 (59 mm SL) left side: a) in alcohol; b) radiograph (photos Dirk Neumann).

FIGURE 2. Serranus pulcher specimen from Príncipe Island, directly after capture (photo Dave Catania).

FIGURE 3. The most common color pattern of Serranus FIGURE 4. Color of paratype ZSM 43880 shortly before pulcher; near Santana Islet, São Tomé (photo Peter Wirtz). capture (photo Nuno Vasco Rodrigues).

FIGURE 5. Rare color pattern of Serranus pulcher, near Rolas Islet, São Tomé (photo Peter Wirtz).

FIGURE 6. Rare color pattern (frightened animal) of Serranus pulcher from near Rolas Islet, São Tomé (photo Peter Wirtz).

FIGURE 7. Rare color pattern of Serranus pulcher from Príncipe Island (photo Dave Catania).

FIGURE 8. Throat color of Serranus pulcher, near San- tana Islet, São Tomé (photo Peter Wirtz).

FIGURE 9. Juvenile (about 4 cm TL) near Bom Bom Islet, Príncipe (photo Peter Wirtz ).

FIGURE 1. Holotype of Serranus pulcher sp. nov. ZSM 43868 (59 mm SL) left side: a) in alcohol; b) radiograph photos Dirk Neumann).

FIGURE 12. Serranus heterurus from the Cape Verde Islands (photo Rogelio Herrera).

FIGURE 15. Serranus heterurus in alcohol; specimen from the Cape Verde Islands (ZSM 430516) (photo Dirk Neumann). FIGURE 14. Throat of Serranus heterurus from the Cape Verde Islands (photo Patrick Louisy).