Development of larval snailfishes (Pisces: Cyclopteridae: Liparidinae) from the western North Atlantic

Abstract

Development of 9 of the 14 snailfishes in the western North Atlantic is described. Identification of larvae of Careproctus reinhardi, six species of Liparis (L. atlanticus, L. coheni, L. fabricii, L. gibbus, L. inquilinus, L. tunicatus), and two species of Paraliparis (P. calidus, P. copei) is based on body proportions, pigmentation, meristic characters, and early development of adult characters. Liparis fabricii is distinct from all other Liparis in having the darkest pigmentation at all sizes, largest sizes at all development stages, and unique body proportions. Liparis atlanticus and L. inquilinus are dissimilar to all other Liparis in the relatively smaller sizes at comparable stages of development and the presence of a notched dorsal fin. They differ from each other in pigmentation pattern and eye diameter/disk length ratio. Liparis coheni and L. gibbus are relatively smaller at all stages of development than L. fabricii but larger than L. atlanticus and L. inquilinus, and lack a notch in the dorsal fin. Liparis gibbus differs from L. coheni in pigmentation pattern and in having a larger eye diameter/disk length ratio. Pronounced geographic variation in pigmentation occurs between L. gibbus from the Canadian Arctic and those from the Gulf of St. Lawrence. The two Paraliparis and C. reinhardi possess adult fin ray counts and pigmentation at hatching and are easily distinguishable. Development in the latter species, which hatch as demersal juveniles, is distinctly different from that in Liparis, which hatch early in development (preflexion) and are pelagic until caudal formation is nearly complete (late flexion). For each species we include larval diagnostic characters, descriptive development (morphometric, pigmentation, meristic), and geographic and seasonal distribution of larvae.