FISHERY BULLETIN: VOL. 76, NO. 4 



Research Submersible Johnson-Sea-Link II, of the 

 Harbor Branch Foundation, Inc. The adult 

 galatheids inhabited a large clump of ivory tree 

 coral which grew in 80 m of water on Jeffs Reef, 

 lat. 27°32.8'N, long. 79°58.8'W, located about 17 n. 

 mi. (27 km) northeast of Ft. Pierce Inlet, Fla. The 

 entire coral colony was collected and returned to 

 the surface inside of a 500-/u,m mesh cloth bag. 

 Ambient seawater temperature on Jeffs Reef was 

 12°C at time of collection. The galatheids were 

 immediately placed in compartmented plastic 

 trays containing recently collected neritic seawa- 

 ter previously chilled to 10°C. Upon return to the 

 laboratory each adult specimen was transferred to 

 individual 100 x 80 mm covered glass laboratory 

 dishes filled with approximately 340 ml of seawa- 

 ter previously chilled to 15°C. Each isolated 

 female was maintained at this temperature, pro- 

 vided a change of chilled seawater, and fed freshly 

 hatched Artemia salina nauplii, daily. All speci- 

 mens were exposed to a 12-h light-12-h dark il- 

 lumination program in a controlled temperature 

 unit (CTU) until hatching occurred. Five females 

 survived in this regimen and yielded larvae over a 

 period from 16 April to 6 May 1977. 



Seven larval series were initiated. Using 

 methodology previously described by Gore 

 (1968), five such series were cultured in 24- 

 compartmented plastic trays. These consisted of 

 two series of 8 and 24 larvae, held in the CTU at 

 15°C ( ±0.5°C), and three series of 24 larvae each, 

 maintained at cool laboratory room temperature 

 (ca. 20°C, ±1°C). Two mass culture series of about 

 30 larvae each were also established in individual 

 100 X 80 mm glass dishes at cool laboratory room 

 temperature, which was controlled by reverse- 

 cycle air conditioning, and was monitored daily 

 with a 7-day recording thermometer. Fresh 

 surfzone seawater (35.5-36%o) was collected week- 

 ly, filtered through glass wool, stored in 14-gal (ca. 

 56-1) polypropylene carboys, and used throughout 

 the rearing period. 



All larval series were checked daily, and any 

 molts or dead individuals were recorded and pre- 

 served in IWc ethanol. Specimens were examined 

 microscopically, slides prepared, and drawings 

 made as described in previous studies by Gore 

 (1968). Measurements given below are the arith- 

 metic average of all specimens examined in any 

 particular stage. A complete series of larvae, or 

 their molts, is deposited in the National Museum 

 of Natural History, Washington, D.C. (USNM 

 170862); the Allan Hancock Foundation, Univer- 



782 



sity of Southern California, Los Angeles (AHF 

 1028-01); the British Museum (Natural History), 

 London (BMNH 1978:103); and the Rijksmuseum 

 van Natuurlijke Historie, Leiden (D 31735). 



RESULTS AND DISCUSSION OF 

 THE REARING EXPERIMENT 



Galathea rostrata passes through four or five 

 morphologically distinct zoeal stages and a single 

 megalopal stage, before completing development 

 in the laboratory. Culture temperature undeni- 

 ably affects duration of development, and perhaps 

 larval survival as well. While the duration of the 

 zoeal and megalopal stages differed at each rear- 

 ing temperature, it was nevertheless generally 

 consistent within each of the temperature series, 

 as will be discussed below. 



At 15°C five morphologically distinct zoeal 

 stages were observed for those larvae surviving to 

 metamorphosis. The minimum time required to 

 pass through these stages and attain megalopal 

 stage was 52 days. Most larvae remained in each 

 zoeal stage approximately 9-11 days through the 

 first four stages. Only two stage V zoeae survived, 

 and they remained as such 14 and 16 days before 

 molting to megalopa. However, neither of these 

 specimens survived longer than 6 or 7 days as 

 megalopae, so the mean duration of the postlarval 

 stage at 15°C remains unknown (Table 1). With 

 the minimum noted period of 6-7 day duration for 

 megalopae at this temperature, completion of de- 

 velopment and metamorphosis to first crab stage 



Table l. — Duration of larval and postlarval development in 

 Galathea rostrata under laboratory conditions at the indicated 

 temperatures. 



Temp 

 and 



Days required to attain next stage 



'One zoea remained 30 days in stage II, dying 13 days later in stage III. 

 ^Combined megalopae data include stages obtained from both IV (ad- 

 vanced) and IV (regular). 



