FISHERY BULLETIN: VOL. 69. NO. 2 



crustecdysone, and fi-esh male crabs were used 

 for each different concentration. The male 

 crabs were held for several days in isolation 

 from female crabs before testing. 



ISOLATION COLUMNS 



Columns (5 x 50 cm) of Amberlite XAD-2, a 

 divinylbenzene polymer, were found to be ef- 

 fective in the recovery of polar steroids from 

 seawater. The columns were washed with three 

 void volumes of water to remove the salts, and 

 the polar steroids were eluted with three volumes 

 of 60 Sr ethanol. The more nonpolar lipids were 

 removed with 95 '^r ethanol. After repeated use 

 the columns were reconditioned by cycling 

 through 95 "^r ethanol, diethyl ether, hexane, 

 diethyl ether, ethanol, and water. 



FRACTIONATION COLUMNS 



Chromosorb 102, which is an 80/100 mesh 

 fraction of Amberlite XAD-2, in a 0.9 X 100 cm 

 column was used to fractionate the ]iolar lipids. 

 This column was eluted with a gradient of eth- 

 anol (20^; to 80 r; ) (Hori, 1969). The gradient 

 was formed by an Isco Dialagrad dual pump" 

 with the following settings: 40 ml/hr; reser- 

 voir for "A" pump, 80 "^r ethanol; reservoir for 

 "B" pump, 20*"^ ethanol; percentage settings 

 for "B" pump, 100, 100, 90, 80, 70, 60, 50, 30, 

 15, 0, (this pump makes five intermediate li- 

 near steps between each setting) ; total time 16 

 hr. The fractionation was monitored at 254 /jl 

 with an Isco Model UA-2 UV monitor and frac- 

 tions were collected in an Isco Model 327 fraction 

 collector. 



A silicic acid column (0.6 X 30 cm) eluted 

 with chloroform-ethanol (5; 1, v/v) and mon- 

 itored in the UV was employed for further 

 fractionation (Horn et al., 1968). 



OBSERVATIONS ON THE PREMATING 



BEHAVIOR AND THE SEX PHERO- 



MONE OF Pachygrapsus crassipes 



Although the premating behavior of the lined 

 shore crab, Pachygrapsus crassipes, as described 



by others (Hiatt, 1948; Bovbjerg, 1960), did 

 not include the typical stance of other Brach- 

 yura, the abundance and ease of collection of this 

 specie.? prompted us to re-examine their be- 

 havior. We found that male P. crassipes, in 

 the presence of a premolt female, exhibit an 

 easily recognizable stance. The males elevate 

 their cephalothoraxes and tilt the anterior 

 margin up. They walk on the tips of the dactyls 

 of their first three pairs of walking legs and 

 extend their fourth pair horizontally backwards. 

 The chelipeds are partially extended but lowered, 

 as opposed to the elevated defensive position. 

 When thus stimulated they will often attempt 

 to seize any other P. crassipes they encounter, 

 male or female, and turn them over into the 

 holding position with which they maintain con- 

 trol of a premolt female. This behavior com- 

 pares with that described by Ryan (1966) for 

 male P. sanguinolentiis. There were two ad- 

 ditional characteristics of the male P. crassipes 

 behavior that paralleled the premating behavior 

 of Cancer magister as described by Snow and 

 Neilsen (1966). They observed that the male 

 C. magister, while carrying the female, fre- 

 quently extended his fourth pair of walking legs 

 straight back. We have observed that C. ynagis- 

 fer will thus extend his legs while holding his 

 body elevated when stimulated by the sex phe- 

 romone before he seizes the female, as does P. 

 crassipes. Snow and Neilsen (1966) also noted 

 that "on occasion the male would rise up on 

 the tips of his walking legs and raise the female 

 up into an elevated position nearly 6 inches 

 off the bottom of the tank. This movement 

 would be accompanied by a continuous flexing 

 of the male's abdominal flap." A frequent ob- 

 servation with pairs of P. crassipes was that 

 they would stand facing each other, both with 

 their legs extended and body elevated, but with 

 the male higher. In this position the female 

 would lower her abdominal flap slowly and then 

 flex it rapidly but not into a completely re- 

 tracted position. She would repeat this move- 

 ment several times. The male would then repeat 

 an identical movement of his abdominal flap. 



' Reference to commercial products does not imply 

 endorsement. 



338 



