DESCRIPTION OF LARVAE OF THE GOLDEN KING CRAB, 

 LITHODES AEQUISPINA, REARED IN THE LABORATORY 



Evan Haynes 1 



ABSTRACT 



Larvae of golden king crab, Lithodes aequispina, were reared in the laboratory from Stage I through 

 Stage V (glaucothoe). Each of the five larval stages is described and illustrated. Zoeae of L. 

 aequ ispina are distinguished from zoeae of L. maja and L. anta rctica by the number of telsonic setae 

 and the length of the posterolateral spines on somites 2-5. The glaucothoe of L. aequispina are dis- 

 tinguished from glaucothoe of L. maja and L. antarctica by the terminal configuration of the 

 carapace spines. Zoeae of L. aequispina are distinguished from zoeae of Paralithodes spp. by 

 number of telsonic setae and by setation of the antennal flagellum. Morphological differences be- 

 tween larvae of Lithodidae and Paguridae are greater than previously believed. 



Information on the larval stages of the genus 

 Lithodes is meager — only the larvae of Lithodes 

 maja (Linnaeus) from the North Atlantic Ocean 

 and larvae of L. antarctica (Jacquinot) from the 

 South Pacific Ocean have been described (Sars 

 1890; MacDonald et al. 1957; Campodonico 

 1971). In this paper, I describe larvae of the 

 golden king crab, L. aequispina (Benedict), from 

 the North Pacific Ocean and compare them with 

 larvae of L. maja, L. antarctica, and Para- 

 lithodes spp., and with larvae of the subfamily 

 Pagurinae (family Paguridae). 



METHODS 



An ovigerous L. aequispina releasing larvae 

 was collected from waters of southeastern 

 Alaska (lat. 58°41.5'N, long. 135°05'W) during a 

 National Marine Fisheries Service trawling 

 survey. The specimen was caught 9 March 1979 

 at 292 m. Bottom water temperature was 2.3°C. 

 The female was placed in about 2, 500 1 of filtered 

 seawater at 2.3°C. Hatching resumed immedi- 

 ately, and the first samples were taken about 10 

 min later. No prezoeae were seen. The samples 

 were preserved in a 5% solution of Formalin 2 

 and seawater. 



About 4 h after hatching, 10 larvae were trans- 

 ferred to each of 30 250 ml jars containing about 

 200 ml of filtered seawater at 6.8°C. The jars 

 were checked daily for exuviae, and a few larvae 



■Northwest and Alaska Fisheries Center Auke Bay 

 Laboratory, National Marine Fisheries Service, NOAA, P.O. 

 Box 155, Auke Bay, AK 99821. 



2 Reference to trade names does not imply endorsement by 

 National Marine Fisheries Service, NOAA. 



Manuscript accepted November 1981. 

 FISHERY BULLETIN: VOL. 80. NO. 2. 1982. 



were preserved every other day. The individuals 

 and cast skins of various stages provided a con- 

 tinuous sequence of stages. Seawater in the 

 holding containers was changed every other day, 

 and the larvae were fed plankton daily that was 

 strained through a 0.333 mm mesh. The density 

 of food was controlled only to the extent that a 

 few food items remained in the container at the 

 end of each feeding period. 



Terminology, methods of measuring, tech- 

 niques of illustration, and nomenclature of ap- 

 pendages follow Haynes (1973, 1976). Setation 

 formulae are the number of setae per segment 

 from the distal segment to the proximal 

 segment. For clarity in the illustrations, setules 

 on setae are usually omitted, but spinulose setae 

 are shown. A minimum of five larvae of each 

 stage was used to verify segmentation and 

 setation. 



Only those morphological characteristics 

 useful for readily identifying each stage are 

 given. 



STAGE I ZOEA 



Mean total length of Stage I zoeae (Fig. 1A), 

 7.3 mm (range 6.8-7.7 mm, 20 specimens). No 

 chromatophores; internal thoracic area orange — 

 coloration same throughout all larval stages. 

 Rostrum slightly sinuate, without teeth, about 

 three-fourths length of carapace. Posterolateral 

 spines on carapace. Eyes sessile. 



Antennule (Fig. IB).— First antenna, or anten- 

 nule, with unsegmented, tubular basal portion 

 (peduncle) and two distal, conical projections. 



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