Monocentris Bloch & Schneider, 1801

Su, Yo, Lin, Hsiu-Chin & Ho, Hsuan-Ching, 2022, A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782), Zootaxa 5189 (1), pp. 180-203 : 183

Monocentris Bloch & Schneider, 1801

Monocentris Bloch & Schneider, 1801:100

(Type species: Monocentris carinata Bloch & Schneider 1801 ).

Lepisacanthus Lacepède, 1801:320

(Type species: Lepisacanthus japonicus Lacepède 1801 ).

Ericius Tilesius, 1809:243

(Type species: Monocentris carinata Bloch & Schneider 1801 ).

Two genera are recognized in the family Monocentridae . Monocentris differs from Cleidopus De Vis, 1882 , in having a broad (deep) suborbital space (> 8.2 % SL); a large mouth with upper jaw straight; relatively long snout, subequal to eye diameter; a black light organ at tip of lower jaw; toothless vomer; and relatively smaller maximum size (usually less than 15 cm SL), whereas Cleidopus has a very narrow suborbital space with lower margin of eye almost adjacent the upper jaw (2.9–3.2 % SL); small with S-shaped upper jaw; snout clearly shorter than eye diameter; an orange light organ on each side of lower jaw under eye; vomer with teeth; and a relatively larger maximum size (up to 26 cm).

According to Paxton (1999), the lateral line is absent in monocentrids, however, our specimens possess a small canal through each scale in a row where a lateral line is commonly found in beryciform fishes (LLS in Fig. 1 ). Thus, we recognized this row of scales as lateral-line scales.

Previously, the genus has comprised two species: M. japonica in the Indo-West Pacific and M. reedi in the southeastern Pacific. A third species similar to M. japonica is described below.

Figures

FIGURE 1. Definition of scale rows counted in Monocentris spp. AS, abdominal scutes; LLA1 and LLA2, scales rows above lateral line; LLB1, LLB2, LLB3 and LLB4, scale rows below lateral line; and LLS, lateral-line scales. Colors in key correspond to colors identifying scale rows.