FISHERY BULLETIN: VOL. 71, NO. 1 



Female crabs were held individually in 1-liter 

 beakers containing 600 ml of aerated, unfiltered 

 seawater, standing in trays of running seawater 

 ranging in temperature from 10.8° to 15.2°C. 

 The water in the beakers was changed every 2 

 days. Larvae released by the females were re- 

 moved from the beakers as soon as a hatch was 

 discovered. Only actively swimming larvae of 

 normal appearance were used. 



Glassware for handling and culturing larvae 

 was washed in fresh water, rinsed with distilled 

 water, and steam autoclaved to minimize mi- 

 crobial contamination of the cultures. Seawater 

 used for culturing was collected at high tide from 

 the laboratory seawater system, passed through 

 a sintered glass filter of pore size 40-60 m/x, and 

 stored at 9°C in darkness. The salinity of this 

 water ranged from 32.8 to 33.7^f. 



Laboratory-hatched larvae of Pachycheles 

 rudis and Petrolisthes eriomerus were cultured 

 in flasks, while P. cinctipes larvae were reared 

 in mass cultures only. Larvae from a single 

 Pachycheles pubescent female were divided be- 

 tween flask and mass cultures. Light received 

 by the larvae was not controlled. In all flask 

 cultures larvae were maintained without aer- 

 ation, initially with six to eight zoea I larvae per 

 Erlenmeyer flask. The seawater volume allow- 

 ance ranged from 25 ml per larva for early 

 stages to 50 ml per larva for the larger later 

 stages. Flasks were maintained at either 12°C 

 or 15°C (± O.OrC) in refrigerated baths of 

 circulating water. All flask cultures were ex- 

 amined daily, mortality recorded, and newly 

 molted larvae transferred to new cultures. 

 Plankton tows were made intermittently from 

 May through September of 1968 in Yaquina Bay 

 and 1 mile outside the estuary along a rocky reef 

 paralleling the shore. The catch was immedi- 

 ately resuspended in cold seawater and kept 

 under refrigeration while being taken to the lab- 

 oratory. Live porcellanid larvae obtained in 

 these hauls were removed to fresh seawater, 

 sorted by zoeal stage, and further separated into 

 four groups on the basis of differences in the 

 patterns of the primary red chromatophores. 

 Larvae within each group were further divided 

 and placed in flask cultures. 



Mass cultures of laboratory-hatched Petrolis- 

 thes cinctipes larvae were maintained in 5-gaI 

 carboys filled with filtered seawater, with 150 or 

 fewer larvae per carboy. Aerated mass cultures 

 were immersed in baths of running seawater 

 and experienced a temperature range of 10.8° 

 to 15.2°C during the culture period and a max- 

 imum daily fluctuation of 2.5°C due to tidal in- 

 fluence. Larvae in mass culture were trans- 

 ferred to clean containers and fresh seawater 

 every 14 days. 



Zoea larvae were fed Artemia salina nauplii 

 not more than 3 days old daily if required so 

 that excess food was always present. The meg- 

 alopa larvae required suspended algal material 

 as food. Several monoalgal {Tetraselmis sp., 

 Isochrysis sp.) and diatom (unidentified) cul- 

 tures were tried singly and in combinations as 

 a food source. Nutrient culture medium inoc- 

 ulated with raw seawater was also used as a 

 source of food organisms. Small stones were 

 introduced into the flasks to provide the mega- 

 lopae with a surface for settling. 



The larvae of the two Petrolisthes species and 

 Pachycheles rudis were reared to the megalopa 

 stage in cultures from embryos obtained from 

 females held in the laboratory. Live larvae of 

 these species taken from the plankton were 

 reared to confirm stages obtained from the lab- 

 oratory-hatched broods and to supplement labo- 

 ratory-grown material for descriptive purposes. 

 The larval history of P. pubescens was first de- 

 scribed from larvae captured in the plankton and 

 placed in laboratory cultures. Three gravid 

 females of this species were collected later, and 

 the identity of the planktonic larvae was con- 

 firmed by comparison with larvae released by 

 one of the females and reared to the second zoeal 

 stage. 



Larvae in various stages of development were 

 preserved for dissection primarily in 70 9^ eth- 

 anol, but a few larval specimens were preserved 

 in a mixture of 50 9<^ glycerine and 509^ ethanol 

 for chromatophore examinations. Both tem- 

 porary and permanent slides were made of the 

 dissected materials. Temporary mounts were 

 made in glycerine, and permanent mounts were 

 made in Zeiss hardening phase medium as well 



190 



