Higuchi's Sea Catfish

description

Description. (Tables 1 and 4). Head moderately long and depressed, profile slightly convex at level of frontals and supraoccipital. Body wider rather than deeper on pectoral girdle area. Cephalic shield relatively short, slightly rugose, wide on lateral ethmoid, frontal, and supracleithrum areas, relatively broad at frontal area. Osseous bridge formed by lateral ethmoid and frontal long and slender, quite evident under skin. Dorsomedian groove of neurocranium formed by frontals and supraoccipital relatively deep and large, its margins well marked and progressively narrower posteriorly. Supraoccipital process relatively short and broad on posterior portion, profile straight. Nuchal plate crescent-shaped, long and wide. Snout short, rounded on transverse section. Anterior and posterior nostrils moderately distant from one another. Eye lateral and small. Interorbital distance relatively long, distance between nostrils and orbit moderate. Maxillary barbel reaching proximal half of pectoral-fin spine, external mental barbel surpassing margin of gill membrane, internal mental barbel reaching margin of gill membrane. Mouth relatively narrow, lower jaw arched. Lips thick, lower lip thicker

Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species

diagnosis

Diagnosis. Cathorops higuchii can be distinguished from all congeners by having 18 - 21 gill rakers on first arch (vs. 14 - 16 in C. aguadulce, 14 - 15 in C. fuerthii, 37 - 40 in C. hypophthalmus, 14 - 16 in C. kailolae, and 13 - 16 in C. manglarensis), slightly granulated cephalic shield (Fig. 13) (vs. remarkably granulated cephalic shield in the remaining species, except in C. taylori), and orbit diameter 11.7 - 18.9 % of external mental barbel length (vs. 26.2 - 51.8 % in C. agassizii, 24.8 % in C aguadulce, 19.6 - 27.7 % in C. dasycephalus, 8.8 - 9.1 % in C. hypophthalmus, 24.8 - 37.6 % in C. kailolae, 23.8 - 47.6 % in C. liropus, 26.4 - 42.0 % in C. taylori, and 23.4 - 24.8 % in C. steindachneri). Cathorops higuchii is further distinguished from C. aguadulce by having 17 - 21 gill rakers on second arch (vs. 13 - 16), shorter snout (6.1 - 8.0 vs. 9.3 - 11.6 % SL), smaller orbital diameter (3.3 - 4.4 vs. 4.6 - 6.9 % SL), and by lacking fleshy papillae intercalated with gill rakers on first two gill arches (vs. papillae present). Cathorops higuchii additionally differs from C. belizensis by having a longer dorsal-fin spine (18.6 - 22.2 vs. 15.9 - 17.6 % SL) (Fig. 9), dorsal-fin s

Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species

discussion

Remarks. The marine and brackish species of Cathorops, occurring from Costa Rica and Panama, have frequently been misidentified as C. melanopus (Steindachner, 1876; Meek & Hildebrand, 1923; Miller, 1966; Gilbert & Kelso, 1971) or C. spixii (Taylor & Menezes, 1978). Meek & Hildebrand (1923) identified specimens collected in Panama as C. melanopus, but noted that the specimens differed from those described by Günther (1864) and Regan (1907) concerning the number of gill rakers on first arch, length of anal fin, number of anal-fin rays, and rugosity on head. They considered the differences to be individual variations without specific value or probably errors in counting number of rays and gill rakers. Our examination of the same specimens revealed that they differ from C. melanopus and represent a new species, herein described as C. higuchii. The records of C. melanopus from coastal waters in Honduras, Nicaragua, Costa Rica and Panama are considered erroneous and should indeed be referred as C. higuchii.

Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species

distribution

Distribution. The species is common along most of the Caribbean portion of CentralAmerica, from Honduras to Panama (Fig. 11). Cathorops higuchii inhabits shallow coastal areas and low portions of coastal rivers

Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species