FISHERY BULLETIN: VOL. 71, NO. 1 



compartment it was preserved, along with its 

 molt, the following day. 



Measurements of the larvae were made with 

 an ocular micrometer and are given in milli- 

 meters; drawings were made with the aid of a 

 camera lucida. Ten individuals, of each stage, 

 and their molts were examined and measured for 

 the developmental series. Carapace length mea- 

 surements were made from the anterior edge 

 of the carapace (posterior edge of eye sockets) 

 to the posterior margin, along the midline. Total 

 length represents the distance from the tip of 

 the rostral spine to the tip of the telson along 

 the curves of the dorsal midline. The setae on 

 some appendages have been shortened or deleted 

 in some of the illustrations to ensure clarity, 

 but are given full descriptions in the text. 



RESULTS 



A prezoea stage of short duration, four zoeal 

 stages, and a megalopa stage were obtained. The 

 prezoeae measured about 2.8 mm in total length. 

 The following are the average number of days 

 from one stage to the next at temperatures of 

 18° to 21°C; first stage zoea to second, 7 days; 

 second to third, 6; third to fourth, 5; fourth to 

 megalopa, 7; and megalopa to first crab, 14. Two 

 abnormalities were observed; a first stage zoea 

 with the protopodite of one antenna forked from 

 the base, and a second stage zoea with the large 

 lateral spine on one side of the telson forked 

 from its base. The larvae are usually light red- 

 dish brown in gross appearance. Some indi- 

 viduals are quite light in appearance but both 

 phases exhibit numerous melanophores scattered 

 over the entire body, particularly on the cephalo- 

 thorax and along the outer margins of the ab- 

 domen. Small melanophores are often scattered 

 on the basipodite on the maxillipeds, 



DESCRIPTION OF THE LARVAE 

 ZOEA I (Figure lA) 



Carapace length 0.83 mm (0.81-0.86); total 

 length 3.71 mm (3.67-3.73). Carapace with 

 rostral, lateral, and dorsal spines. Rostral spine 

 strongly depressed; slightly longer than anten- 



nae and nearly three quarters the length of the 

 dorsal spine. Lateral spines flexed slightly ven- 

 trad, broad based, and nearly as long as the 

 rostral spine. Width of the carapace from tip to 

 tip of lateral spines about half the total length of 

 the body. Dorsal spine long and curved slightly 

 posteriad; its length about one-third the total 

 length of the body. A short slender seta is pre- 

 sent on each side of the carapace, in line with 

 the posterior margin of the dorsal spine's base. 

 The eyes are not stalked. Abdomen with five 

 somites and the telson (Figure 2H). Abdominal 

 somites two through five with lateral spines 

 (fifth somite in some individuals without 

 spines) ; those on second somite fairly blunt and 

 directed somewhat anteriad; spines on somites 

 three through five sharper and hooked posteriad, 

 decreasing in size posterially. Posterior lateral 

 margin of somites three through five produced 

 into long, sharp spines. Second somite with two 

 setae on middorsal surface; somites three 

 through five with two setae each on posterodorsal 

 margin. Telson bifurcate with three pairs of 

 setae on the inner side. Each furca with two 

 lateral spines, one long and strong, the other 

 much smaller, and a small dorsal spine. Anten- 

 nule (Figure 2B) with four unequal aesthetes 

 and a small seta terminally. The antenna (Fig- 

 ure 2A) bears a long protopodite with a row of 

 spinules on the outer margins; the exopodite is 

 about half the length of the protopodite and 

 terminates in a spine and one seta. Mandible 

 (Figure 2C) with two large teeth anteriorly, 

 a medial blade, and a toothed edge posteriorly. 

 Themaxillule (Figure 2D) bears a two-segment- 

 ed endopodite, the short proximal segment bears 

 one long plumose seta, the distal segment with 

 six long plumose setae, two of which are subter- 

 minal; the basal and coxal endites each bear six 

 spinous setae. The scaphognathite of the max- 

 illa (Figure 2E) has seven marginal plumose 

 setae and a plumose apical tip; the endopodite 

 is bilobed with five spinous setae on the distal 

 lobe and three on the proximal; basal and coxal 

 endites each bilobed with 5 + 5 and 3 + 3 

 spinous setae respectively. There is a suggestion 

 of two segments in the exopodite of the first 

 maxilliped (Figure 2F) which bears four, one- 

 jointed, natatory setae terminally; endopodite 



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