Tosanoides aphrodite, Pinheiro, Hudson T., Rocha, Claudia & Rocha, Luiz A., 2018

Pinheiro, Hudson T., Rocha, Claudia & Rocha, Luiz A., 2018, Tosanoidesaphrodite, a new species from mesophotic coral ecosystems of St. Paul's Rocks, Mid Atlantic Ridge (Perciformes, Serranidae, Anthiadinae), ZooKeys 786, pp. 105-115 : 106-109

Tosanoides aphrodite sp. n. Figures 1, 2, 3, 4, Table 1

Type locality.

Saint Paul’s Rocks, Brazil.

Material.

Holotype. CIUFES 3444 (Field number: CR 055). 56.8 mm SL, male, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017 (Figure 1). Paratypes. CAS 244382 (Field number: CR 071). 54.9 mm SL, male, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017. ZUEC 16842 (Field number: CR 077). 59.9 mm SL, male, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017. BPBM 41351 (Field number: CR 070). 57.1 mm SL, female, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017. MZUSP 123538 (Field number: CR 079). 38.9 mm SL, female (juvenile), Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017. CAS 244383 (Field number: CR 078). 47.5 mm SL, female, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017 (Figure 2). USNM 440405 (Field number: CR 080). 33.1 mm SL, female (juvenile), Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017.

Comparative material.

We compared Tosanoides aphrodite to other Anthiadinae species using the keys for the Western Central Pacific Anthiadinae species in Heemstra and Randall (1999) and for the Atlantic and Eastern Pacific Anthiadinae species in Anderson and Heemstra (2012). Data from Tosanoides obama Pyle, Green & Kosaki, 2016, Tosanoides flavofasciatus Katayama & Masuda, 1980, and Tosanoides filamentosus Kamohara 1953 are from Pyle et al. (2016), Katayama and Masuda (1980), and Kamohara (1953), respectively.

Diagnosis.

The new species differs from all other Anthiadinae by the following combination of characters: Dorsal-fin spines X; last dorsal spine the longest, 1.8-2.2 in head length; dorsal-fin rays 15-16; 7th dorsal ray the longest, 2.65-2.80 in head length; anal-fin rays 9; pored lateral-line scales 32-35; ventral scale rows 9-10; body slender and compressed, greatest depth 2.96-3.18 in SL, and the width 1.77-2.09 in depth. Our phylogenetic analysis shows the new species belongs to Tosanoides Kamohara 1953, from which it differs of the other known species by: a divergence of at least 12.35% at the cytochrome oxidase I gene, last dorsal spine the longest (instead first through fourth), fewer dorsal-fin rays (15-16 vs. 16-17), and more anal-fin rays (9 vs. 8 in the other Tosanoides ).

Description.

Morphometric and meristic data for type specimens are provided in Table 1. Dorsal fin X, 15 (15-16), last soft ray branched to base; anal fin III,9, last soft ray branched to base; pectoral-fin rays 14 (14-15); pelvic-fin rays I,5; principal branched caudal rays 7 + 6 (7 + 6), upper procurrent and rudimentary unbranched caudal rays 9 (9), lower procurrent and rudimentary unbranched caudal rays 8 (8-9); pored lateral-line scales 34 (32-35); scale rows above lateral line to origin of dorsal fin 3; scale rows below lateral line to origin of anal fin 10 (9-10); gill rakers on upper limb 8, on lower limb 22; vertebrae 27 (10 precaudal + 17 caudal).

Body slender, compressed, its greatest depth 3.18 (2.96-3.13) in SL, the width just posterior to gill opening, 1.89 (1.77-2.09) in depth; head length 2.79 (2.88-3.52) in SL; snout short, its length 6.08 (4.88-7.12) in head; orbit diameter 3.34 (2.48-3.32) in head; interorbital convex, the least bony width 3.94 (2.78-4.03) in head; caudal peduncle depth 3.21 (2.33-3.56) in head. Mouth large and oblique; lower jaw not projecting beyond the upper when mouth closed; maxilla 2.15 (1.96-2.16) in head, diagonal (45°), and reaching the center of pupil. One pair of nostrils in front of each eye with no membranous tube or rims. One pair of pores on top of head between eyes, slightly anterior to center of eyes. Posterior margin of eye bordered with eight to ten pores. Lateral line very high, parallel with dorsal profile, forming an angle below last few dorsal rays and extending along middle of caudal peduncle to base of caudal fin.

Teeth in upper jaw villiform, forming a band broader anteriorly with two canines on each side, one externally directed forward and other internally directed backward, an outer row of approximately 14 slender canines on each side of jaw curved forward; lower jaw with a patch of villiform teeth anteriorly; two canines on each side anteriorly curved backwards and a third canine on each side facing forward and curved internally, an outer row of approximately 15 slender canines like those of upper jaw, pointing forward; small teeth on vomer and palatines; tongue pointed, smooth. Preopercle with a round angle, upper limb serrate with approximately 25 spinules, lower limb smooth; opercle with two flat spines, upper one longest and at apex; subopercle and interopercle smooth.

Color in life.

Tosanoides aphrodite is sexually dichromatic. Males (Figure 3A): body pinkish and reddish, darker dorsally fading to white ventrally; two alternating bright yellow and pink stripes from anterior end of body through nape across the operculum, continuing to area below middle of spinous dorsal fin and becoming series of irregular spots on posterior third of body; third yellow stripe of similar pattern from lower jaw to caudal fin becoming series of irregular blotches under pectoral fin; eye yellow with bright pink upper and lower edges; snout and region anterior to eye bright yellow with a thin pink stripe extending dorsally to two thirds distance to origin of dorsal fin; scales on ventral portion of head and body with bright yellow margins; dorsal fin yellow with bright purplish pink margin; anal fin yellow also with bright pink margin from first to seventh ray and along posterior margin of last ray; pelvic fin yellow with pink anterior margin; caudal fin pink posteriorly and yellow with irregular pink markings anteriorly; filaments in upper and lower edges yellow; pectoral fin translucent yellow.

Females and juveniles (Figure 3B) predominantly reddish orange slightly darker dorsally; snout and region anterior to eye bright yellow with a thin red stripe extending dorsally to two thirds distance to origin of dorsal fin; two alternating yellow and red stripes from anterior end of body through nape to the operculum; third yellow stripe from lower jaw to base of pectoral fin; eye greenish yellow with bright purple upper and lower edges; scales on body with red margins; dorsal fins predominantly yellow with orange rays and dark red blotch covering first three dorsal spines; anal fin predominantly yellow with orange rays and orange margin; pelvic fin yellow with purplish red anterior margin; caudal fin yellow with pinkish orange margins and vertical lines forming ocellated and irregular markings; pectoral fin translucent orange.

Color in alcohol.

Straw-colored; fins transparent; eyes black (Figure 1). Females retain dark blotch on first three dorsal fin spines (Figure 2).

Etymology.

The name " aphrodite " refers to the ancient Greek goddess of love and beauty. While we were collecting the Aphrodite anthias, a large Six-gill shark ( Hexanchus griseus ) came very close to both of us (HTP and LAR), but that didn’t divert our attention from the new exquisitely beautiful species, and we never even saw the shark (https://youtu.be/pSZrmoEwR0Q). The beauty of the Aphrodite anthias enchanted us during its discovery much like Aphrodite’s beauty enchanted ancient Greek gods.

Distribution and habitat.

Tosanoides aphrodite is only known from Saint Paul’s Rocks, off Brazil. It was found on mesophotic coral ecosystems of the island, observed between 100 and 130 m depth while rebreather diving, and a single observation at 260 m depth, taken from a submersible dive. The species inhabits small crevices of complex rocky reefs (Figure 4). The ambient seawater temperature at the collecting depth (~ 120 m) varied between 13 and 15 °C during the two-week period we stayed in the area.

Comparative remarks.

The COI gene sequence of Tosanoides aphrodite is 12.65% divergent from Tosanoides obama , and on average 14-20% divergent from other genera of Anthiadinae. Because we do not have sufficient representation for members of this subfamily, no phylogenetic tree is provided here. In addition to the unique characters presented in the diagnosis section, Tosanoides aphrodite also differs from Tosanoides filamentosus in having a shorter snout and larger orbit (4.9-7.1 and 2.5-3.3 vs 4.6 and 3.7 in HL, respectively). Tosanoides flavofasciatus differs from Tosanoides aphrodite in having a shorter fourth (2.55-2.75 vs. 2.02-2.40 in HL) and last (3.11-3.44 vs. 1.82 and 2.17 in HL) dorsal spine length, 7th dorsal ray the longest instead the third, smaller third anal spine (2.65-2.80 vs. 1.89-2.62 in HL), and longer pectoral fin length (2.36-2.71 vs. 2.72-3.05 in SL). Tosanoides obama also differs from Tosanoides aphrodite in having a shorter fourth (2.4-2.68 vs. 2.02-2.40 in HL), fifth (2.4-2.88 vs. 1.94-2.29 in HL) and last (2.67-3.06 vs. 1.82-2.17 in HL) dorsal spine length, 7th or 8th dorsal ray the longest instead the third, and longer pectoral fin length (2.49-2.63 vs. 2.72-3.05 in SL).