WILLIAMS: CRABS OF THE GENUS CALLINECTES 



male, last two segments nearly equal in length, 

 telson triangular with slightly inflated sides, 

 apices acute. First gonopods of male (Figures 18f, 

 20g, h) reaching about to abdominal locking 

 tubercles on fifth sternite, often partially overlap- 

 ping near base, tapering to narrowly flared tips 

 bent ventrolaterally and opening mesioventrally, 

 armed with scattered minute spinules sternally 

 and laterally and with a subterminal sternome- 

 sial row of elongate slender spinules. Gonopores of 

 females (Figure 22f) elliptical with long axis in 

 transverse plane, sinuous aperture of each with 

 rounded margins except mesial side sloping from 

 surface under overhanging anterior and inferior 

 bulbous posterolateral border. 



I? 

 Size of carapace in mm. — Largest male: length 



54, width at base of lateral spines 93, including 

 lateral spines 123. Largest female: length 55, 

 width at base of lateral spines 96, including lat- 

 eral spines 114. Summary of selected measure- 

 ments is given in Tables 1 and 2. Estevez (1972) 

 judged females to attain sexual maturity at a 

 length of 28-34 mm, but smaller ones are known 

 (see Spawning). 



Color. — Male: "Carapace dull olive gray-green. 

 Chelipeds olive green dorsally, whitish ventrally, 

 washed with bluish-violet and chelae tipped with 

 pale yellow-brown. Legs turquoise washed with 

 olive; hairs straw gold; swimming legs olive green 

 with suggestion of turquoise, paddles washed with 

 black; hairs straw; tubercles at leg joints golden 

 orange; eyes straw with brownish streaks; under- 

 parts pure white" (Garth, 1961b; Garth and 

 Stephenson, 1966). 



Female: Carapace generally blue, central por- 

 tion blue violet; anterolateral portions deep 

 purplish- vinaceous. Chelipeds with base of merus 

 olive, inner portion of hands blue- violet, remain- 

 der purplish but varied, fingers barred with pur- 

 ple, propodal fingers usually white tipped. Re- 

 maining legs Italian blue, hairs olive, swimming 

 legs with articulations and margins narrowly vio- 

 let, paddles sometimes turquoise. Abdomen violet, 

 joints and sternum white (Garth, 1961b). 



Variations. — Lateral spines in C. arcuatus vary 

 considerably, some being relatively no longer 

 than in C. exasperatus. Inner orbital fissures are 

 open in some individuals. Chelipeds often have 

 smooth ridges rather than granulate ones, and the 

 propodal molariform complex of the major chela is 



often worn. The proximal portion of abdominal 

 segment 6 may be almost completely uncalcified 

 in males. 



Variations in C. arcuatus are often those as- 

 sociated with proportional growth changes. These 

 are pronounced enough to make identification 

 difficult, especially among juveniles. Callinectes 

 pleuriticus and C. dubia were based on immature 

 C. arcuatus. The mesogastric area grows rela- 

 tively broader with the maturing carapace. Adult 

 females have a more arched carapace than the 

 immature, and seemingly more females than 

 males have a hairy growth under the anterolat- 

 eral border. First gonopods of juvenile males are 

 short; those of adult males range in length from 

 short, with tips terminating at level of the suture 

 between thoracic sternites VI and VII, to long, 

 terminating near the suture between thoracic 

 sternites IV and V. The tips of these appendages 

 usually curve ventrolaterally but may curve ven- 

 trally, mesially, or asymmetrically, and the slen- 

 der distal portions occasionally are sinuous rather 

 than straight. Subterminal dorsal spinules may 

 be worn off of first gonopods. 



An ovigerous female from Panama (AHF, Stn. 

 111-33) has seven anterolateral teeth on the left 

 side. 



Distribution. — Los Angeles Harbor, Calif., to 

 Mollenda, Peru; Galapagos Islands (Figure 24). 

 The record from southern Peru is an immature 

 male. A record from the Galapagos Islands in 

 April 1941, is a soft mature male, and two other 

 records in February 1964, are an immature male 

 and female. 



Habitat. — Garth and Stephenson (1966) sum- 

 marized habitat as sand or mud bottom, oyster 

 beds, lagoons, estuaries, channels among man- 

 groves, or river mouths. Recorded depth range is 

 shoreline to 27.5 m, with many occurrences lim- 

 ited to shallows less than 1 or 2 m along shore, 

 but Estevez (1972) reported common occurrence in 

 Colombia on sand or sand-mud bottom, preferen- 

 tially between 10 and 20 m in salinities 22%o or 

 higher. Estevez found the diet included mainly 

 crustaceans, bivalves, fishes, inorganic remains, 

 gastropods, and cephalopods in order of prece- 

 dence (330 stomachs examined). 



Spawning. — The spawning season extends year 

 round. Museum records include ovigerous females 

 as follows: January, Costa Rica; March, Oaxaca, 



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