FISHERY BULLETIN: VOL. 72, NO. 3 



than anterior margin. Surface of carapace dor- 

 sally smooth and glistening around perimeter 

 (when wet) and on epibranchial and posterolateral 

 surfaces; granules scattered on epibranchial sur- 

 faces, progressively more crowded on proto-, 

 meso-, and anterior portion of metagastric areas 

 and branchial lobes and on cardiac area (espe- 

 cially posterior slope). Epibranchial line promi- 

 nent and relatively uninterrupted, sulci on cen- 

 tral part of carapace deeply etched. 



Chelipeds granulate on ridges, fingers of major 

 chela heavily toothed, lower margin of propodal 

 finger often decurved near base in adults. 



Male abdomen and telson long, extending to 

 anterior quarter of thoracic sternite IV; telson 

 lanceolate, much longer than broad; sixth seg- 

 ment of abdomen broadened distally. Mature 

 female abdomen and telson reaching at least as far 

 forward as in male, nearly to juncture between 

 thoracic sternites III and IV, sixth segment as long 

 as fifth and fully rounded at its distolateral 

 corners, telson elongate-triangular with sides 

 slightly inflated. First gonopods of male (Figures 

 19b, 20o) very long, often extending nearly to tip of 

 telson and crossed near tips; sinuously curved and 

 overlapping in two places proximally, diverging 

 distally, twisting mesioventrally on axis lateral to 

 abdominal locking tubercles on thoracic sternite 

 V, and recurving gradually to termination near 

 midline; armed distally with a dorsolateral band 

 of large and small retrogressive spinules. Gono- 

 pores of female (Figure 221) asymmetrically ovate 

 in outline with apex on long axis directed an- 

 teromesad; aperture of each sloping from surface 

 on mesial side under rounded sinuous anterolat- 

 eral border superior to rounded lateral and much 

 smaller mesial eminences on posterior border. 



Size of carapace in mm. — Largest male avail- 

 able: length 78, width at base of lateral spine 134, 

 including lateral spines 159. Largest female 

 available: length 58, width at base of lateral 

 spines 102, including lateral spines 124. Taissoun 

 (1972) measured large samples made up of indi- 

 viduals whose mean sizes were comparable to the 

 above specimens, males generally being larger 

 than females. Summary of selected measurements 

 for the few specimens available is given in 

 Tables 1 and 2. 



The following account is from Taissoun (1972), 

 the only person who has studied the species in 

 detail. 



Color. — Adult male: carapace olive green with 

 tints of light brown and blue toward central 

 region, anterolateral region with light chestnut 

 areas. Chelipeds with upper portion light chestnut 

 and olive green with orange tints; distal portions 

 of merus, internal portion of carpus, internal and 

 external sides of fingers intense blue; spines of 

 merus brownish orange distally with tips light 

 chestnut and cream, bases obscure brown; distal 

 tubercles on propodus orange and intense blue. 

 Ambulatory legs cream proximally, blue distally, 

 articulations with tubercles intense orange. 

 Swimming legs intense blue and cream dorsally, 

 terminal article blue, obscure brown and light 

 orange, tubercles orange. Underparts cream and 

 light yellow, except anterior portion and 

 pereopods light blue. 



Females: as males but with more intense blue 

 on internal part of chelipeds. Taissoun (1972) 

 included colored illustrations, but the female 

 pictured is more reddish than as described above. 



Variation. — Granulation of the carapace varies 

 from nearly smooth to fairly marked, but is not so 

 prominent as in some specimens of C. bocourti. 

 Lateral spines of males are occasionally curved 

 forward at the tips, but in females are often 

 relatively longer and straighter. Meral spines on 

 the chelipeds vary in number as usual in the genus 

 (four or five) and all spines become worn in old 

 individuals. 



Distribution . — Confined to the Lago de 

 Maracaibo estuarine system, roughly 120 km 

 wide X 215 km long, extending from Bahia del 

 Tablazo emptying into Golfo de Venezuela in 

 north, through Estrecho de Maracaibo southward 

 into Lake proper. 



Habitat. — The species occurs on sandy and 

 muddy bottoms, and among roots of mangroves, in 

 brackish to occasionally fresh waters containing 

 much silt and decomposing organic material. Both 

 C. maracaiboensis and bocourti occur in the Lake 

 and its outlet, apparently most abundantly near 

 the mouth where all developmental stages of both 

 are found, but the majority of these are adult 

 males in salinities ranging from 0.35 to 15.12/(o. 

 Surface temperatures in the Lake are fairly uni- 

 form, ranging from 27.2° to 32°C, and undergoing 

 a diurnal change of ± 1°C, but below depths of 10 m 

 temperature remains even more uniform. Tem- 



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