Growth, Morphology, and Laboratory Culture of Larvae of Balanus Glandula (Cirripedia: Thoracica)

Abstract

Nauplii of Balanus glandula obtained from gravid adults were cultured in the laboratory. Morphological descriptions and drawings of the six naupliar stages and the cyprid are presented. The nauplii generally followed the typical developmental pattern of Balanus. Total length (mean ± two standard deviations) of the nauplii increased from 271 ± 16 μm at stage I to 745 ± 116 μm at stage VI. All naupliar stages had a trilobed labrum. Setation of the antennule followed the typical balanid pattern through development; beyond stage I both rami of the antenna and mandible had one or two fewer setae than is typical. The patterns of setation were increasingly variable through development. Within stages, the mandibular exopodite was the ramus with the most consistent setation pattern, while the mandibular endopodite had the least consistent setation pattern. For larvae cultured individually in wells of tissue culture plates, the highest daily rate of metamorphosis to the cyprid occurred 11 days postliberation, with 41% cumulative yield. For mass cultures the metamorphosis rate peaked 13-14 days postliberation, with 56% cumulative yield. Cyprids produced in the mass cultures after 11-12 days of growth averaged 690 ± 60 μm in length; new cyprids appearing after 15-20 days of growth averaged 590 ± 40 μm in length.