pliosoma stage which may at times be freed in the 

 water but this has yet to be confirmed.) The 

 puerulus is shaped like a miniature adult, but is 

 about 17 mm. long, colorless, and has a soft exo- 

 skeleton. It is nonplanktonic and settles in shal- 

 low water. Ten postlarval stages have been dis- 

 tinguished. Stages one through three avoid light, 

 hut later stages show no such reactions. At the 

 end of the first year, at the eleventh postlarval 

 stage, the young are approximately 2 inches long. 



Aside from reactions of the very young post- 

 larvae to light, Hess (1940) showed that freshly 

 molted adults are sensitive to light in many re- 

 gions of their bodies, but as soon as the body is 

 again sclerotized no such reactions are apparent, 

 Sutcliffe (1956) demonstrated that in clear, shal- 

 low water lobsters sought cover in bright moon- 

 light. He concluded that movements attributed 

 to tidal responses were actually responses to light. 



Stridulation by spiny lobsters (Palinuridae) 

 has been described by a number of workers 

 (Moulton, 1957) and in P. argus it is produced 

 primarily by a toothed ridge medial to the bases 

 of the antennae and extending anteriorly from be- 

 neath each eye. A corrugated membrane at the 

 base of each antenna is played against this ridge, 

 producing sound when the membrane is moved 

 proximally. Two types of sound are produced, a 

 slow rattle normally produced by animals in small 

 groups, and a rasp which accompanies defensive 

 behavior. A squeaking sound is also produced in 

 an unknown manner, by vibration of the body, 

 when a specimen is held in the hand of an ob- 

 server. The effect of these sounds on other lobsters 

 or marine life is unknown. 



Pearse (1932a) determined the freezing point of 

 P. argus blood at Tortugas (range —1.86° to 

 -2.39° C). 



Family Scyllaridae. Spanish lobsters 



Carapace depressed; exoskeleton thick, hard, 

 sculptured or tuberculate; orbits excavated in 

 margins of dorsal surface. Antennae short and 

 broad with flat scalelike, stiff articles. Mandibles 

 with a one-jointed palp. Leps simple except 

 minutely chelate fifth pair in female. 



The fossil record for (lie family Scyllaridae 

 extends back to the lower Eocene of the Gulf 

 Coast in North America (Rathlmn, 19."..')). 



KEY TO GENERA AND SPECIES IN THE CAROLINAS 



( Adapted in part from manuscript key by 

 F. A. Chace, Jr.) 



a. Exognath of outer maxillipeds without a flagellum ; 

 terminal article of antennae with edge cut into deep 



Idbes distally Scyllarus (p. 94). 



b. Prominences on carapace blunt ; second article of 

 antennular peduncles dorsally flattened ; distal ar- 

 ticles of antennae meeting, or nearly meeting, in 

 midline ; first four abdominal tergites obscurely 

 notched posteriorly in midline ; pleura of fourth 

 abdominal segment rounded laterally, 

 c. Pregastric tooth of carapace broadly rounded ; two, 

 seldom three, distinct parallel grooves between pos- 

 terior marginal groove and posterior margin of 

 carapace ; first to fourth abdominal segments with 

 notch in posterior margin very shallow ; fourth 

 abdominal segment not elevated in midline 



t-hncri (p. 95). 

 ce. Pregastric tooth almost always bilobed, incised ; 

 almost always a single distinct groove between 

 posterior marginal groove and posterior margin of 

 carapace ; first to fourth abdominal segments 

 showing a deep, narrow, median notch in posterior 

 margin ; fourth abdominal segment elevated, more 



or less ridgelike in midline amcricanns (p. 96). 



Mi. One gastric and all lateral prominences on carapace 

 sharp : second article of antennular peduncles cylin- 

 drical ; distal articles of antennae not nearly meeting 

 in midline : first four abdominal tergites deeply and 

 acutely notched posteriorly in midline; pleura of 

 fourth abdominal segment sharply rectangular or 



acute laterally nciirctits (p. 97). 



aa. Exognath of outer maxillipeds with a flagellum ; 

 terminal article of antennae with edge nearly smootti 

 or crenulate distally Scyllarides nodifer (p. 98). 



Genus Scyllarus Fabricius, 1775 



Fabricius, 1775, p. 413. 



Recognition characters. — Carapace flattened, 

 width at anterolateral corners equal to or slightly 

 greater than length in midline; middorsal ridge 

 and an oblique ridge on each side prominent. An- 

 tennules with first articles broad, flattened, and 

 immovable, second article much narrower and 

 elongate; third and fourth articles slender; fla- 

 <iella short; abdomen, including telson, much 

 longer (nearly twice) than carapace; pleura of 

 first segment incised in center of lower edge, 

 second broad and pointed distally. Anterior pleo- 

 pods of male witli both rami slender, flattened, 

 hairy on outer border; remainder with exopods 

 small and lamellate, endopods rudimentary. An- 

 terior pleopods of female with both rami broad 

 and flattened; exopods of remainder lamellate. 



94 



FISH AND WILDLIFE SERVICE 



