JOHNS and LANG LARVAL DEVELOPMEN1 OF UBIN1A EMARQ1NATA 



AN I i Figu re I 1 )) Pedunclei 3 tegmented; 

 basal segment bare, Becond and thud segment 

 with l shorl Beta each. Inner flagellum unseg- 

 mented with 3 terminal Bimple etae doi al 

 flagellum 2-segmented proximal segmenl with 5 

 aesthetascs; distal with 3 aesthetascs and I sub 

 terminal imple seta. 



AN2 (Figure 1C) Peduncle 3-segmented. 

 Flagellum 4-segmented, with 2 distal segments 

 having 3 subterminal and 4 terminal simple setae, 



respect i vel y. 



M N I Figure 5A i Palp 3-segmented wit h 5 tei 

 minal setose 3etae 



MAX1 (Figure 5B) — Endopodite unsegmented 

 witli 2-3 terminal simple setae. Basal endite with 

 14 processes (6 plumodenticulate cuspidate 6 

 plumodenticulate, 2 short multidenticulate) and 

 2-3 marginal plumose setae; coxa! endite with 3 

 plumodenticulate and 3 simple terminal setae and 

 4 subterminal plumose setae. 



MAX2 (Figure 5C)- Scaphognathitewith31-33 

 < in South Carolina reared) or 33-35 'm Rhode Is- 

 land reared and field samples) plumose marginal 

 setae. Endopodite with 0-1 seta. Basal endite 

 bilobed; distal portion and proximal portion with 

 6-7 plumodenticulate or plumose setae each. 

 Coxal endite bilobed; distal portion with 3 

 plumose setae and proximal portion with 4 

 plumose and 1 simple setae. 



MXP1 (Figure 5D)— Exopodite 2-segmented, 

 proximal segment with 1 plumose seta; distal 

 segment with 5 plumose and 1 simple setae. En- 

 dopodite unsegmented with 1-3 terminal setae. 

 Basal endite with 8-10 plumodenticulate setae; 

 coxal endite with 6 plumodenticulate and 1 

 plumose setae. Epipodite with 4 long simple 

 setae. 



MXP2 (Figure 5E) — Exopodite 2-segmented; 

 distal segment with 5-6 long plumose setae. En- 

 dopodite 4-segmented; setation formulae (proxi- 

 mal to distal) 0, 1, 3, 6. Distal setae, 5 plumoden- 

 ticulate cuspidate, 1 simple. 



MXP3 (Figure 5F)— Exopodite 2-segmented; 

 terminal segment with 3-4 long plumose and 2 

 small simple terminal setae. Endopodite 

 5-segmented; setation formulae (proximal to dis- 

 tal) 9-10, 7-8, 4, 6, 4, mostly plumodenticulate or 

 serrate plumose setae. Epipodite with 3 terminal 

 and 3 subterminal multidenticulate setae. 



PI to P5 (Figure 4 A, E) — Moderately setose, 

 cheliped similar to adult form. 



PL2 to PL6 (Figure 4F)— Exopodite 

 2-segmented; plumose natatory setae on distal 



segment vanes from ll (PL2) to 8 (PL5). Endopo 



dite small with 2 small books. 

 Zoeal Chromatophores 



Libinia emarginata larvae are sparsely pig- 

 mented m freshly sacrificed specimen 

 Chromatophore color ranges from orange to a dark 

 brown-red, Distinctive pigment areas with little 

 individual variation include an orange spot at the 

 posterior dorsal spine base, a deep red area po te 

 rior to the eye base, a large distinctive red spot on 

 the posterolateral carapace region near the 

 carapace setae and red pigmentation of the man 

 dibles. The abdomen is pigmented in the central 

 ventral area of each segment juncture. Additional 

 pigment spots occur on I he carapace and append 

 ages but do riot appear consistent in location or 

 occurrence. 



DISCUSSION 



There is only a narrow range of temperature 

 salinity conditions at which the larvae succe 

 fully develop in the laboratory. With South 

 Carolina larvae, these conditions are 25 C and 

 30%o, while with Rhode Island larvae, maximum 

 development occurs at 20°C and 30%o. The differ 

 ence in these temperature possibly reflect-, the 

 influence- of latitudinal separation on larval de 

 velopment, however, until critical experiment 

 are undertaken, this cannot be confirmed (Vein 

 berg 1062; Vernberg and Costlow I960; Sastry 

 1970; Sastry and Vargo 1 977 1. The larvae develop 

 besl in temperatures that represent the mean 

 temperature during the larval season. Gravid L. 

 emarginata were collected from May to September 

 in South Carolina in coastal waters that bad a 

 mean water temperature near 25 C. In Rhode Is- 

 land, gravid crabs were collected from July to Au- 

 gust in bay and coastal waters that had a mean 

 water temperature near 20 C 



The narrowness of successful rearing conditions 

 may reflect inadequate rearing variables such as 

 diet, substrate, water circulation, etc. (Rob< 

 1972; Sulkin 1975; Sulkm and Norman 1976), or 

 reflect the habitat of L. emarginata. With larvae 

 that develop entirely in bay or coastal wat< 

 I here fol lows a characteristic inability of larvae to 

 develop successfully over wide range- of tempera- 

 ture and salinity, while larvae from estuarine 

 waters usually develop in a much wider range of 

 temperatures and salinity. In the offshore 



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