FISHERY BULLETIN: VOL. 72, NO. 3 



Mexico, Panama; April, between San Felipe and 

 mouth of Colorado River, Mexico, Peru; May and 

 June, Sinaloa, Mexico; July, Panama; August, 

 Jalisco, Mexico; September, Guerrero, Mexico; 

 November, Sonora and Jalisco, Mexico; De- 

 cember, Sonora, Mexico. A female from near the 

 mouth of the Colorado River (AHF, Golfo de 

 California, 6-9 April 1947, Stn. H47-53) is the 

 smallest egg bearer seen in this species, the 

 carapace having a length of 23, and width at base 

 of lateral spines 39, or including lateral spines of 

 52 mm. Month of collection is unknown for an 

 ovigerous female from Anaheim Slough, Calif., in 

 1928. Estevez (1972) considered ovigerous females 

 rare. 



Remarks. — The cognate species C. arcuatus and 

 C. danae are so similar that differentiation is 

 difficult except on grounds of male first gonopod 

 morphology or geographic distribution. In gen- 

 eral, C. arcuatus is the more robust species, hav- 

 ing a tumid carapace emphasized in the arched 

 anterolateral border and inflated branchial re- 

 gions. Anterolateral teeth stand up from the sur- 

 face, as if each is reinforced with an axial rib 

 extending from the borders of the anterolateral 

 area, but almost never are shoulders developed on 

 their margins, whereas in C. danae there is less 

 prominent central reinforcement in the teeth but 

 a tendency to development of shoulders. Such dif- 

 ferences are inconsistent. 



Distribution of C. arcuatus along the Pacific 

 side of Baja California parallels, but is more ex- 

 tensive than, that of C. bellicosus. In this region, 

 marine climate that is transitional between trop- 

 ical and dominant temperate extends from Punta 

 Entrada (Bahia Magdalena) to Point Conception 

 north of Santa Barbara Channel (Garth, 1961a). 

 Here temperate and tropical faunas mingle, but 

 tropical elements thin out in the north surviving 

 only in protected areas or in favorable years. 

 Records of C. arcuatus along this outer coast are 

 less numerous than in the Golfo de California and 

 southward, but occurrence of an ovigerous female 

 at Anaheim Slough, Calif., indicates enough 

 tolerance of temperate conditions to develop 

 breeding populations, at least in favorable years. 

 Callinectes arcuatus shows adaptation to a 

 broader spectrum of marine climates than C. 

 bellicosus in its much more extensive distribu- 

 tion from temperate southern California, through 

 the essentially insular oceanic province at the tip 

 of Baja California and tropical eastern Pacific, to 



temperate fringes of the Humboldt Current along 

 Peru. 



Callinectes arcuatus is questionably listed from 

 the Caribbean side of Colombia at Turbo on the 

 Golfo de Uraba in MCZ lot 9666. I agree with the 

 cataloger that this must be an erroneous locality 

 for the collection. 



A collection of C. arcuatus from Estero de los 

 Algodones, SE of Guaymas, Sonora, Mexico 

 (USNM 15431) contains a large female which has 

 a broken male first gonopod inserted in the left 

 genital opening. The gonopod fragment is 14 mm 

 long, completely inserted, and is that of a male C. 

 arcuatus. 



Brocchi's (1875) discussion of male gonopods in 

 Callinectes is a puzzle because there is no sure way 

 to know which species he studied; neither his de- 

 scriptions nor figures are accurate enough to allow 

 certainty in forming synonymy. This would be of 

 no real concern were it not for the relationship of 

 his work to that of Milne Edwards (1879). Brocchi 

 studied material obtained from Milne Edwards, 

 and both considered gonopod structure of males to 

 be among the diagnostic characters for species or 

 "varieties" of Callinectes. Reasonable assessment 

 of Brocchi's material rests on the geographic 

 source of material then available, his discussion, 

 and its probable influence on Milne Edwards's 

 thinking. The evidence is present in both papers. 

 Summarizing: species with short first gonopods 

 came from the Antilles, coast of America, and 

 Chile; those with long ones came from Cayenne 

 and Guatemala. Chile must be regarded as an 

 erroneous locality for species in this genus (Garth, 

 1957). 



Milne Edwards (1879) described C cayennensis 

 (= C. bocourti) with long first gonopods from 

 Cayenne and remarked on likeness of the male 

 gonopods to those of C. hastatus. Brocchi (1875) 

 may have worked with C bocourti from Cayenne 

 but more likely with C. hastatus (= C sapidus) 

 itself, for he remarked on its broad, strong frontal 

 teeth and designated it as the hastata of Ordway 

 (plate 16, Figure 81). 



By designation "very long," Brocchi indicated 

 that his illustration of male first gonopods from 

 Guatemalan material (plate 16, Figure 82) must 

 refer to C arcuatus, a species regarded as having 

 nearly straight gonopods (Milne Edwards, 1879). 



Species with short male first gonopods from 

 provenances listed by Brocchi (1875) and de- 

 scribed in more detail by Milne Edwards (1879) 

 were: Antilles, C. ornatus and larvatus (= C. 



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