FISHERY BULLETIN; VOL. 77, NO. 4 

 Table l, — Survival, development time, and duration of the larval stages oi Hypoconcha sabulosa reared in the laboratory. 



Item 



Zoea I 



Zoea II 



Zoea III Magalopa 



1 St crab 



Percent survival tram first zoeal stage to successive stages (% based 



on original 22 minus those sacrificed for figures) 

 Percent survival within each stage (% of stage not sacrificed to reach 



subsequent stage) 

 Days from hatching to reach each stage mean (range) 

 Duration of each stage in days mean (range) 



3 6 (3-6) 



At 25° C, 25%o salinity, development to first crab 

 averageci 21 days (Table 1). Mean duration of each 

 zoeal stage was 3 or 4 days while the megalopa 

 lasted approximately 10 or 11 days. Mean sizes and 

 ranges for five larvae at each stage are given in 

 Table 2. 



Table 2.- 



-Size o(Hypoconcha subuhsa larvae stages, based on 

 five larvae at each stage. 



Larval Description 



LiveH. sabulosa zoeae are strong, active swim- 

 mers which readily capture Artemia salina nau- 

 plii. At first sight they generally look like large, 

 proportionally short and bulky pagurid zoeae. The 

 zoeae have a generally reddish-brown color and 

 are most noted by the distinctive line of 

 chromatophores along the ventral and posterior 

 carapace margin (Figure 1). 



Figures of the larval stages show the most com- 

 mon arrangement of setal numbers observed. For 

 the most part, the figures should be self- 

 explanatory; the descriptive text is intended to 

 note significant morphological features and out- 

 line setal numbers with observed variations. 



Zoea I 



Carapace (Figure 1 A, a) without dorsal and lat- 

 eral spines, rostrum directed anteriorly, ven- 

 trolateral carapace margin smooth. Carapace 

 striated with crisscrossing fine ridges giving a tex- 

 tured "skinlike" appearance. At least one pair of 

 transverse grooves evident, eyes sessile. 



Abdomen (Figure lA, a) without spines or dis- 

 tinct projections, somite six and telson fused, 

 small pleopod buds may be present. 



Telson (Figure 2 A) triangular with distinct me- 

 dian notch; setation 1+1 with outer fixed spine, 

 hairlike plumose seta, and five large plumose 

 setae. 



ANl (Figure 3A) — Single segment; terminal 

 setation of three aesthetascs and two simple setae; 

 subterminal setation of two plumose setae. 



AN2 (Figure 3E) — With 10 plumose setae on 

 scale and 4 plumose setae on endopodite. 



MN ( Figure 4 A, a) — With concave median sur- 

 face and lateral serrate rim. Ventroposterior re- 

 gion with asymmetric group of teeth. 



MAXl (Figure 5A) — With two-segmented en- 

 dopodite, distal segment with six setae, proximal 

 segment with two setae; basal endite with three 

 cuspidate and two plumodenticulate setae; coxal 

 endite with four stout multidenticulate setae, 

 three plumodenticulate setae, and one simple 

 seta. 



MAX2 (Figure 6A) — With indistinctly seg- 

 mented endopodite, 2 or 3 setae; bilobed basal en- 

 dite, distal lobe with 5 setae, proximal lobe with 5 

 setae, bilobed coxal endite, distal lobe with 5 setae, 

 proximal lobe with 9 setae, scaphognathite with 

 17 or 18 marginal plumose setae. All setae 

 plumose, plumodenticulate, or simple. 



MXPl (Figure 7A) — Exopodite with four 

 plumose setae; endopodite five-segmented with 

 numerous median margin setae and one lateral 

 margin seta on distal segment. 



MXP2 (Figure 7E) — Exopodite with four 

 plumose setae; endopodite four-segmented with 

 indicated pattern of median margin setae and one 

 lateral margin seta on distal segment. 



MXP3 — Limited to undeveloped bud. 



PI (Figure 7L) — Unsegmented biramous ap- 

 pendage with up to two plumose setae. 



Z..ca II 



Carapace (Figure IB, b) with same basic fea- 

 tures as stage I but with two distinct pairs of 

 transverse grooves; eyes stalked. 



Abdominal somites (Figure IB) with pleopod 

 buds; somite six and telson partially fused. 



852 



