LECITHOTROPHIC DEVELOPMENT OF THE GOLDEN KING CRAB LITHODES AEQUISPINUS (ANOMURA: LITHODIDAE)

Abstract

ABSTRACT Larvae of the golden king crab Lithodes aequispinus were reared in individual chambers in the laboratory from hatching to the first crab stage (C1). The experiment included 2 treatments: 1 group was fed live nauplii of Artemia daily, while the other group was unfed. A total of 4 molts were observed for all larvae from hatching to Cl. One larval stage, either zoea III or zoea IV, was skipped by all larvae. No significant difference existed for the duration of development of each stage between fed and unfed treatments. The mean durations were ZI (ZI = zoeal stage I, ZII = zoeal stage II, etc.) = 6.6 days (±0.71 SD), ZIIa (molted to ZIII) = 7.0 d (±0.65 SD), ZIIb (molted to ZIV) = 8.8 d (±0.95 SD), ZIII (skipped ZIV) = 12.0 d (±1.33 SD), ZIV (skipped ZIII) = 9.3 d (± 1.63 SD), and glaucothoe = 41.3 d (±2.65 SD). The total larval duration was approximately 67 d. The survival rate of the fed group was significantly lower than that of the unfed group. Seventeen percent of unfed larvae developed to Cl, but only 0.7% of fed larvae did so. The longest duration of survival from hatching was 191 d for an unfed crab. The dry weights of unfed larvae decreased 10% from hatching to Cl. Our results indicate that the larval development of the golden king crab is fully lecithotrophic, i.e., larvae can successfully develop to juvenile crabs without eating.