Diamondscales pineapplefish

description

Description. Meristic and morphometric values are provided in Tables 2 and 3. Data below are for the holotype, followed by the range for selected paratypes and non-types in parentheses, except where indicated. Dorsal-fin rays VI, i + 9 = 10 (V – VII, i – ii + 8 – 10 = 10 – 12); anal-fin rays i + 9 = 10 (i + 9 – 10 = 10 – 11); principal caudalfin rays 10 + 9 = 19 (9 – 10 + 9 = 18 – 19), uppermost and lowermost rays unbranched; procurrent caudal-fin rays 5 (4 – 5) dorsally and 4 ventrally; pectoral-fin rays ii + 11 + i = 14 (ii + 10 – 12 + 0 – i = 13 – 15); pelvic-fin rays I, 3; developed gill rakers 6 + 1 + 12 = 19 (5 – 7 + 1 + 10 – 12 = 16 – 20); LLA 1 14 / 13 (12 – 15 / 12 – 15); LLA 2 5 / 5 (2 – 7 / 2 – 6); LLS 14 / 13 (12 – 15 / 12 – 15); LLB 1 10 / 10 (9 – 12 / 9 – 11, mode 10 / 10); LLB 2 7 / 7 (7 – 9 / 7 – 8); LLB 3 7 / 6 (6 – 7 / 6 – 7); LLB 4 3 (prepelvic) + 4 (postpelvic) / 3 + 4; scales surrounding dorsal-fin base 22 (18 – 21); scales surrounding anal-fin base 6 (6 – 8); medium predorsal scales 4 (1 – 4, mode 3); abdominal scutes 2 (rudimentary) + 3 (prepelvic) + 4 (postpelvic) (rarely 2 + 2 + 4); vertebrae 12 + 14 = 26; pyloric caeca 8 (7, n = 2); pseudobranchial filamen

A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782)

description

New English name: Golden-diamond pineapple fish New Chinese name: ḔṖṘ 梨 ⁂ Figs. 2, 5 B, 7 – 10, 12 B, 13 – 14. Tables 2 – 4

A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782)

diagnosis

Diagnosis. A species of Monocentris differing from its congeners in having following combination of characters: LLS 12 – 15; LLB 1 10 – 11, modally 10; LLB 3 6 – 7; total gill rakers 16 – 20; scales between LLB 4 and AS small, its posterior tip not reaching second postpelvic scute; vomer without teeth; and mouth large, reaching a vertical through posterior margin of eye.

A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782)

distribution

Distribution. Records from literature and this study suggest a wide distribution in the western Pacific, including Taiwan (Shao et al. 2013; Koeda & Ho 2019; this study), Korea (Kim & Nakaya 2013), Japan (Shimizu in Masuda et al. 1984; Okamura & Amaoka 1997), the Philippines (Fourmanoir 1981), Vanuatu (this study), the Solomon Islands (this study), and Western Australia and Queensland, Australia (this study). Records from Vanuatu imply it may inhabit depths to 341 m, slightly deeper than that of M. japonica. Genetic analysis. The maximum-likelihood tree strongly supports the monophyly of both M. chrysadamas sp. nov. and M. japonica at species-level distinction, with a 99 % and 81 % bootstrap value, respectively (Fig. 10). Although M. chrysadamas possesses two sub-clades on the tree, the genetic distance calculated by K 2 P model shows only a 0.835 % difference among these two sub-clades, which is much lower than expected species-level differences (Table 4). Overall, M. chrysadamas has a genetic distance of 3.566 % with M. japonica, with an intraspecific distance of 0.424 %.

A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782)