Pseudanthias emma Gill & Psomadakis 2018, new species

Pseudanthias emma new species

Figure 1; Tables 1–2

Emma’s basslet

Holotype. SAIAB 203722, 107 mm SL, off Tanintharyi coast, Myanmar, Andaman Sea, Indian Ocean (11°39.96’ N, 97°16.16’E), 105 m, R/ V Dr. Fridtjof Nansen, stn 149, bottom trawl, 25 May 2015, collected by P. N. Psomadakis.

Diagnosis. The following combination of characters distinguishes Pseudanthias emma from congeners: dorsal rays X,16; pectoral rays 18; lateral-line scales 42; third dorsal-fin spine longest, prolonged; no papillae on posterior margin of orbit; soft part of dorsal with low scaly sheath; subopercle and interopercle indistinctly serrated; caudal fin weakly concave centrally, with elongate filaments extending from second to uppermost and second to lowermost branched rays.

Description. Dorsal rays X,16, all segmented rays branched; third dorsal-fin spine longest, with fleshy pennant extending from tip; anal rays III,7, all segmented rays branched; pectoral rays 18/18, all rays branched except upper 2/2, no serrations on rays; pelvic rays 1,5; caudal fin weakly concave centrally, with elongate filaments extending from second to uppermost and second to lowermost branched rays; principal caudal rays 9 + 8; branched caudal-fin rays 7 + 6; upper procurrent caudal-fin rays 7; lower procurrent caudal rays 7; lateral-line scales 42/42; scales above lateral-line to origin of dorsal fin (counted upwards and forwards from lateral line) 6/6; scales above lateral-line to base of fifth dorsal spine (counted upwards and forwards from lateral line) 4/3; scales above origin of anal fin origin to lateral line (counted upwards and forwards from anal origin) 18/18; circumpeduncular scales 26; gill rakers 11 + 22; branchiostegal rays 7; pseudobranch filaments 20.

Vertebrae 10 + 16; predorsal formula 0/0+0/2/1+1; main shaft (proximal component) of first dorsal pterygiophore roughly perpendicular to long axis of body; no trisegmental pterygiophores associated with dorsal and anal fins; ribs present on vertebrae 3 through 10; epineurals present on vertebrae 1 through 13; paired parapophyses present on first caudal vertebra (see Baldwin 1990: fig. 21B); parhypural and hypurals autogenous; well-developed hypurapophysis on parhypural; epurals 3; single uroneural (posterior uroneural absent); ventral tip of cleithrum with well-developed posteroventral process.

Morphometric values are summarised in Table 1.

Mouth large, slightly oblique, posterior margin of maxilla reaching to vertical through posterior edge of pupil; mouth terminal, lower jaw projecting slightly; premaxilla with an enlarged recurved canine anterolaterally, a band of small conical teeth about five rows wide at symphysis reducing to two rows on sides of jaw, with the outer row teeth larger and slightly curved, and inner pair anteriorly nearest symphysis enlarged and caniniform, directed inwards; dentary with a band of small conical teeth about six rows wide, reducing to single row posteriorly on sides of jaw, an enlarged, curved canine tooth on sides of jaw, and an anteriorly pointing canine tooth anterolaterally; vomer with a triangular patch of small conical teeth, five rows wide in midline; palatine with a narrow band of small conical teeth, three rows wide at widest point; ectopterygoid, mesopterygoid and tongue edentate.

Opercle with 3 flat spines, middle spine longest, upper spine mostly concealed by scales; posterior margin of preopercle with 35/37 fine serrations, these gradually increasing in size until angle of preopercle; no serrations on ventral part of preopercle; interopercle with 1/2 indistinct serrations; subopercle with 2/2 indistinct serrations; posttemporal with about 5 indistinct serrations; no apparent serrations on supracleithrum. Anterior nostril positioned at middle of snout, tubular with elongate flap on posterior rim, flap reaching posterior nostril when laid back; posterior nostril at mid-upper, anterior border of orbit. No papillae on posterior rim of orbit. Snout not hypertrophied at symphysis.

Scales ctenoid with peripheral cteni (Roberts 1993); lateral line broadly arched over pectoral fin following body contour to caudal-fin base; head fully scaled except for lips, and areas in front of and immediately below nostrils; no auxiliary scales on body, a few auxiliary scales on cheeks and operculum; low scaly sheath on soft dorsal and anal fins, with indistinct small scales present between segmented rays; caudal fin with scaly basal sheath, with small scales extending over almost all of fin, except for fin tips and posterior part of membranes of middle rays; pectoral fins with basal, wedge-shaped sheath of small scales; pelvic fins with small scales extending on to basal half of fins.

Colour of male holotype when freshly dead (described from two photos, one with a white background that shows fin coloration better but is not of publishable quality, and Figure 1): head pink, pale pink ventrally, with orange bar extending almost vertically from about 1 o’clock position of orbital rim over nape; two orange stripes, one narrow and from front of eye to snout tip, the other broad and from behind lower half of eye to pectoral-fin base, the stripes bordered ventrally by continuous bright pink (on head) to silvery pink (on pectoral-fin base) stripe; iris bright yellow, with short black crescent near anterior border of eye; body mostly orange, with bright pink band from dorsal-fin origin along dorsal part of body to upper edge of caudal peduncle, the band broader beneath middle of dorsal fin, extending ventrally almost to lateral line; lower part of body silvery white anteriorly on breast, becoming pale pink on lower part of caudal peduncle, separated from orange part of body by narrow silvery white stripe; a large (eye-sized) orange-red blotch on breast, between bases of pectoral and pelvic fins; spinous part of dorsal fin bright orange-yellow with fins spines pink, and distal part of fin behind seventh spine narrowly bright red; soft portion of dorsal fin orange with distal third to half of fin bright red; anal fin pale pink to white, with distal half of soft part of fin bright red; caudal fin narrowly bright pink dorsally and pale pink ventrally, the remainder of fin pinkish red on basal third, pinkish hyaline on middle third, and bright red on distal third, with filamentous tips pale pink to hyaline; pelvic fin pale pink to white with distal tip abruptly bright red; orange stripe on pectoral fin base extends on to fin, becoming reddish orange, this bordered dorsally and ventrally by narrow bright pink (dorsally) or silvery pink to white (ventrally) stripes, the remainder of fin pinkish hyaline.

Colour in preservative: Head and body tan, with no apparent markings; fins pale tan, without markings.

Habitat and distribution. Known only from the holotype, trawled in proximity of a deep coral reef (105 m) off the south east coast of Myanmar in the Andaman Sea (eastern Indian Ocean). The chaetodontids Roa jayakari (Norman) and Heniochus acuminatus (Linnaeus), the priacanthid Pristigenys refulgens (Valenciennes), the lethrinid Wattsia mossambica (Smith) as well as several other reef-associated fish species were caught in the same haul.

Comparisons. Pseudanthias emma closely resembles P. pillai Heemstra & Akhilesh (2012) in general form and coloration. The latter species was described on the basis of two specimens from off Charakkadu, Kerala, India (10°30’ N, 75°24’E). Subsequently, Krishna et al. (2017) described P. vizagensis on the basis of 44 specimens trawled off Visakhapatnam in the Bay of Bengal (stated coordinates 17°10’N, 18°10’E, which is clearly erroneous; possibly 83°10’E was the intended longitude value). The description of P. vizagensis is problematic, not the least of which for the listing of all 44 specimens as “ holotypes ”. Although Krishna et al. (2017) compared their new species with P. pillai, purported differences in coloration and fin shapes are erroneous, and apparent differences in meristic characters (17 versus 19 pectoral-fin rays; 44–45 versus 36–38 lateral-line scales) may reflect different or inaccurate counting methods. We here suggest that the two nominal species are synonyms, though re-examination of the P. vizagensis type specimens (here interpreted as syntypes) will be necessary to reconcile the apparent meristic differences.

Comparison of certain morphometric data provided by Krishna et al. (2017) with their figure 1A indicates that their data are either not compatible or not sufficiently accurate for comparison with P. emma (e.g., head length 40.44–40.65 stated vs ca 36 % SL from figure, predorsal length 38.20–39.56 vs ca 32 % SL, greatest body depth 39.56–44.94 vs ca 37 % SL). We therefore base our morphometric comparison solely on data provided by Heemstra & Akhilesh (2012), though acknowledge that larger sample sizes are needed for proper comparison. Nonetheless, P. emma appears to differ substantially from P. pillai in having a deeper caudal peduncle, longer third dorsal-fin spine, shorter head, broader interorbital, and shorter soft dorsal-fin rays (Table 1). Although similar in coloration, the two species differ in various details (Table 2). They also differ in caudal-fin shape. In P. emma the caudal fin is weakly concave with the second-to outermost branched rays dorsally and ventrally expanded with long filaments, whereas in P. pillai it is weakly convex centrally, with little or no elongation of outer rays (not lunate as stated by Krishna et al. 2017). The two species differ in the number of lower gill rakers (22 in P. emma versus 28–29 in P. pillai). Finally, P. emma possibly differs from P. pillai in having more lateral-line scales (42 versus 36-38), though this assumes the high numbers (44–45) reported for the syntypes of P. vizagensis by Krishna et al. are in error.

Pseudanthias emma is distinguished from all other congeners in having the following combination of characters: dorsal-fin rays X,16, the third spine prolonged; pectoral rays 18; lateral-line scales 42; gill rakers 11 + 22; no papillae on posterior margin on orbit; soft part of dorsal fin with low scaly sheath; subopercle and interopercle indistinctly serrated; and caudal fin weakly concave centrally, with elongate filaments extending from second to uppermost and second to lowermost branched rays. The fresh coloration is also distinctive for the species.

Etymology. The species epithet is for the second author’s daughter Emma. It is treated as a noun in apposition.