Lestidiops Hubbs, 1916

Lestidiops Hubbs, 1916 View in CoL

Distinguishing features. A paralepidid genus with body naked except for a row of lateral-line scales present, gill rakers with single row of short teeth, and greater than 77 total vertebrae (subfamily Lestidinae ). Lestidiops can be distinguished from other genera by the following combination of characters: head, snout and body short to moderately slender, never as slender as in Stemonosudis and Dolichosudis ; nostrils located slightly to well anterior of a vertical through posterior end of maxilla; no light organs or ducts (present in Lestrolepis and Lestidium ); DFO slightly anterior to well-posterior to VFO; DFO ranges from slightly anterior to, right above to well-posterior of anus; anus close to pelvic fin (well-posterior to the fin in Macroparalepis ); anal-fin rays 25‒32 (usually more than 34 in Stemonosudis and Dolichosudis ); lateral-line complete or not (i.e. running to caudal-fin base or not); ventral adipose fin present (absent in Macroparalepis ); and adults with unevenly distributed melanophores to uniformly black.

Remarks. At present, Lestidiops is the most species-rich genus in the family Paralepididae , with about 25 species recognized (not necessarily all valid) based on our investigation (Ho, pers. data). With a great variety of morphological features, there is no unique (apomorphic) character to distinguish the genus from all other genera, except for the combination of characters as provided above. Diagnostic characters used to separate most species are weak, such as positions of DFO, VFO and anus, and many nominal species need further study. Rofen (1966:322) considered there to be 14‒20 valid species and divided the genus into five species groups, without providing distinguishing features among them. However, he also stated that “Just how these should be treated must await further investigations when adequate collections of the more advanced adult stages are available.”