THE LARVAL STAGES OF THE DEEP SEA RED CRAB, 



GERYON QUINQUEDENS SMITH, REARED UNDER 



LABORATORY CONDITIONS (DECAPODA: BRACHYRHYNCHA) 



Herbert C. Perkins^ 



ABSTRACT 



A prezoeal stage, four zoeal stages, and one megalopa stage were obtained from eggs 

 of Geryon quinquedens Smith hatched in the laboratory. Each zoeal stage and the 

 megalopa are discussed and illustrated. 



The commercial potential and abundance of the 

 deep sea red crab, Geryon quinquedens Smith, 

 are discussed by Schroeder (1959), McRae 

 (1961), and Holmsen (1968). The red crab is 

 obviously an important constituent of the deep- 

 water benthic fauna found on the continental 

 shelf off New England and the middle Atlantic 

 states, and its larvae should therefore occur in 

 considerable numbers in the plankton of that 

 region. Knowledge of the larval stages of this 

 species is apparently totally lacking. Brattegard 

 and Sankarankutty (1967) have described the 

 prezoea and the first zoea of Geryon tridens 

 Kroyer from Norway, but I can find no other 

 reference to the larval stages of this genus. 



It is the purpose of this paper to describe the 

 larval stages of Geryon quinquedens so that they 

 may be identified in plankton collections and thus 

 facilitate the understanding of the early life his- 

 tory of this species and hopefully to shed light 

 on its apparently tenuous taxonomic status with- 

 in the Brachyrhyncha. 



METHODS AND MATERIALS 



In February 1971, several berried females of 

 Geryon quinquedens were captured in 300 fm of 

 water (bottom temperature was 5.9°C) in the 

 Baltimore Canyon area of the continental shelf 

 (lat 37°56'N, long 73°55'W) off Delaware Bay. 



' Northeast Fisheries Center, National Marine Fish- 

 eries Service, NOAA, West Boothbay Harbor, ME 04575. 



Manuscript accepted July 1972. 



FISHERY BULLETIN: VOL. 71, NO. 1, 1973. 



Three of the berried crabs were returned to the 

 Boothbay Harbor Laboratory and maintained in 

 shallow tanks at temperatures that ranged from 

 5° to 12°C. On 29 April 1971, one of the fe- 

 males died and some of her eggs were removed 

 and placed in beakers of filtered seawater. Tem- 

 perature in the beakers was 15°C; prezoeae were 

 observed the next day and on 1 May first zoeae 

 were apparent. On 10 May, another female's 

 eggs started hatching in one of the tanks. Water 

 temperature in this tank was 10°C. A prezoea 

 stage was noted in the tank also but lasted less 

 than 1 hr. First zoeae from each of these batches 

 were maintained separately in beakers contain- 

 ing 1,000 ml of filtered seawater and 50,000 units 

 of penicillin plus a small amount of streptomycin 

 (some larvae were raised without the antibiotics 

 with no differences noted). Newly hatched 

 Artemia nauplii obtained from California eggs 

 were given as food. Small amounts of algae 

 (Dimaliella) were also added to sustain the 

 Artemia nauplii. Water and food were changed 

 every other day. At the start the zoeae were 

 maintained at a constant temperature of 15°C, 

 but fouling organisms grew on many of the zoeae 

 and it was necessary to maintain them at room 

 temperature (18°-21°C) to accelerate develop- 

 ment. Salinity ranged 30 to SVu during the 

 study. Zoeae were also put into compartmented 

 plastic trays, one to a compartment, and were 

 maintained as those in the beakers. The zoeae 

 in the compartments were used for the devel- 

 opmental studies. When a zoea molted in a 



69 



