Cathorops (Cathorops) belizensis, Marceniuk & Betancur-R, 2008

Marceniuk, Alexandre P. & Betancur-R, Ricardo, 2008, Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species, Neotropical Ichthyology 6 (1), pp. 25-25 : 25-

Cathorops (Cathorops) belizensis , new species Figs. 7 and 8

Cathorops spixii (non Agassiz); Taylor & Menezes, 1978: (in part) [description and distribution, Belize]

Cathorops sp ; Greenfield & Thomerson, 1997 [description, Belize].

Holotype. USNM 286399 , 175.0 mm SL (female), Belize, Belize City , mangrove swamps St. John´s college, 2 Aug 1971, D. W. Greenfield and J. E. Thomerson.

Paratypes. USNM 385181 , 9 (8, 147.0-240.0 mm SL), collected with holotype ; FMNH 95978 , 52 (3, 207– 248 mm SL), collected with holotype ; FMNH 77783 , 27 (4, 168– 218 mm SL), Belize, 500 yards off Belize City , 1 Aug 1971 D.W. Greenfield .

Diagnosis. Cathorops belizensis is distinguished from all congeners by having 19-20 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 , 13-16 in C. manglarensis , 16-18 in C.melanopus , and 14-18 in C.taylori ), 18-21anal-fin rays (vs. 22-25 in C. fuerthii , 22-23 in C. hypophthalmus , 25-27 in C. multiradiatus , 24-27 in C. manglarensis , 22-25 in C. spixii , and 22-23 in C.steindachneri ), posterior margin of pectoral-fin spine with short and inconspicuous serrations (vs. long and conspicuous serrations in C. aguadulce , C. kailolae , C. melanopus , C. multiradiatus , and C. tuyra ), orbital diameter 3.6-4.4% SL (vs. 4.6-7.1% SL in C. agassizii , 4.6-6.9% SL in C. aguadulce , 3.0-3.5% SL in C. hypophthalmus , 4.6-6.6% SL in C. kailolae , 5.0-6.1% SL in C. liropus , 4.5-5.0% SL in C. melanopus , and 4.6-5.9% SL in C. taylori ), interorbital distance 12.9-15.1% SL (vs. 9.9-12.3% SL in C. aguadulce , 15.7-16.3% SL in C. hypophthalmus , 8.9-12.3% SL in C. kailolae , 11.1-12.1% SL in C. melanopus ), and dorsalfin spine length 29.4-33.3% of distance from tip of snout to pelvic-fin origin (vs. 33.4-53.03%, except in C. taylori , and C. tuyra ).

Cathorops belizensis is additionally distinguished from C. aguadulce by possessing a shorter snout (6.9-8.9 vs. 9.3-11.6% SL), shorter supraoccipital process (8.8-10.5 vs. 11.5-16.3% SL), and by lacking fleshy papillae intercalated with gill rakers on first two arches (vs. papillae present). Cathorops belizensis is further distinguished from C. higuchii by its remarkably granulated cephalic shield (vs. slightly granulated cephalic shield), shorter dorsal-fin spine (15.9-17.6 vs. 18.6-22.2% SL) ( Fig. 9 ), dorsal-fin spine as long as pectoral-fin spine (vs. dorsal-fin spine longer than pectoral-fin spine), and shorter nuchal plate (5.6-6.4 vs. 6.3- 7.5% SL). Cathorops belizensis also differs from C. kailolae by possessing a greater distance between anterior nostrils (5.1-6.1 vs. 3.2-4.5% SL), greater distance between posterior nostrils (5.9- 7.6 vs. 4.1-5.3% SL), shorter dorsal-fin spine (15.9-17.6 vs. 19.3- 24.9% SL), broader mouth (10.0-13.2 vs. 8.1-10.0% SL), wider premaxilla (6.3-11.9 vs. 4.3-5.4% SL), shorter lower lobe of caudal-fin (25.5-28.2 vs. 29.2-34.3% SL), pelvic fin paler (vs. pelvic fin totally or partially dark), and by lacking fleshy papillae intercalated with gill rakers on first two arches (vs. papillae present). Cathorops belizensis is additionally distinguished from C. mapale species group in having a shorter supraoccipital process (8.8-10.5 vs. 10.6-14.9%SL), shorter nuchal plate (5.6-6.4 vs. 6.6-7.9% SL), and shorter dorsal-fin spine (15.9-17.6 vs. 18.5-24.2% SL), dorsal-fin spine as long as pectoral-fin spine (vs. dorsal-fin spine longer than pectoral-fin spine). Cathorops belizensis may be further distinguished from C. melanopus in having a longer head (25.8- 31.9 vs. 22.3-23.0% SL), longer snout (6.9-8.9 vs. 5.3-5.5% SL), greater distance between lateral cornu of lateral ethmoid and external limb of supracleithrum (22.2-26.4 vs. 19.3-19.6% SL), greater distance between anterior nostrils (5.1-6.1 vs. 3.6-4.4% SL), greater between posterior nostrils (5.9-7.6 vs. 4.4-5.1% SL), broader mouth (10.0-13.2 vs. 8.9-9.7% SL), wider premaxilla (6.3- 11.9 vs. 5.1-5.8% SL), and pelvic fin paler (vs. pelvic fin with intense black pigmentation).

Description. ( Tables 1 and 3). Head very long and depressed, profile slightly convex at level of frontals and supraoccipital. Body wider rather than deeper on pectoral girdle area. Cephalic shield long and rugose, wide on lateral ethmoid, frontal, supracleithrum, and epioccipital areas. Osseous bridge formed by lateral ethmoid and frontal long and slender, quite evident 30 Revision of the ariid species of the genus Cathorops under skin. Dorsomedian groove of neurocranium formed by frontals and supraoccipital deep and relatively large, its margins well marked and progressively narrower posteriorly. Supraoccipital process relatively short and wide on posterior portion, profile straight. Nuchal plate crescent-shaped, short and wide. Snout long and rounded on transverse section. Anterior and posterior nostrils quite distant from one another. Eyes lateral and small. Interorbital distance long, distance between nostrils and orbit moderate. Maxillary barbel reaching base of pectoralfin spine, external mental barbel reaching margin of gill membrane, internal mental barbel not reaching margin of gill membrane.

Mouth broad, lower jaw arched. Lips wide, lower lip thicker than upper lip. Vomerine tooth plates absent. One pair of oval shaped accessory tooth plates, moderate in size and distant from one another.Accessory tooth plates with large molariform teeth. Premaxilla broad and short. Dentary with well pronounced posterior projection, with sharp teeth on anterior portion, molariform teeth on posterior portion and few conical teeth on intermediate portion.

Soft pectoral-fin rays 10-11 (10). Pectoral-fin spine relatively short and slender; anterior margin with few granules on basal two thirds, distal third with short serrations; posterior margin straight on basal fourth, distal three quarters with short serrations. Soft dorsal-fin rays 7. Dorsal-fin spine short and slender, as long as pectoral-fin spine; anterior margin with few granules

A. P. Marceniuk & R. Betancur-R. 31

on basal two thirds, distal third with short serrations; posterior margin serrated along almost its entire length. Pelvic fin high, with 6 rays.Anal fin low and short at base, with 18-21 (21) rays. Upper and lower lobes of caudal-fin quite short, upper lobe longer than lower lobe. Caudal peduncle high.

Acicular gill rakers on first arch 19-20 (20), 6 or 7 (6) on upper limb, 12 to 14 (14) on lower limb. Spike shaped gill rakers on second arch 16-19 (19), 6 or 7 (6) on upper limb, 11 to 13 (13) on lower limb. Mesial surfaces of all gill arches with developed gill rakers. Lateral and mesial surfaces of first and second gill arches without fleshy papillae intercalated with gill rakers.

Coloration in Alcohol. Head dark brown on dorsal and lateral portions, ventrally light cream. Body with same dark brown coloration on dorsal portion, progressively lighter towards lateral line and light cream under lateral line. Barbels light, fins light beige.

Sexual dimorphism. Sexual dimorphism was observed in two females (175.0-240.0 mm SL) and seven males (147.0-211.0 mm SL) with respect to following morphological features (see also Table 3). Males with relatively larger heads than females, as evidenced by greater distance between lateral cornu of lateral eth-

32 Revision of the ariid species of the genus Cathorops moid and external limb of supracleithrum, greater interorbital distance, and wider cephalic shield on lateral ethmoids and frontal areas.Anterior portion of body longer in males than in females, as evidenced by distance from tip of snout to pectoral, dorsal and adipose fins and by longer distance from tip of snout to posterior margin of dorsomedian groove of neurocranium.Males with deeper and wider body than females.

Premaxilla wider in males than in females ( Fig.10 ).Accessory tooth plates remarkably longer and wider in females and consequently more distant from one another in males ( Fig. 10 ). Males with smaller and fewer molariform teeth on accessory tooth plates than females.Accessory tooth plates totally or partially covered by epithelial tissue in males. Dentary in females with longer posterior projection and larger and with more molariform teeth on its posterior portion than males ( Fig. 10 ).

Pelvic fin and supraoccipital process longer in females than in males. Females with deeper caudal peduncle and longer upper lobe of caudal fin than males. Males with larger orbital diameter, longer adipose fin, and longer barbels than females.

Distribution. Cathorops belizensis is described from the mangrove channels near St. John´s College at Belize city, Belize ( Fig. 11 ).

Etymology. The specific epithet belizensis derives from the type locality of the species, Belize City.

Vernacular names. Belizean Sea Catfish or bagre de Belize.

Figures

Fig. 7. Cathorops belizensis, holotype, USNM 286399, 175.0 mm SL (body in lateral view). Belize, Belize City, mangrove swamps St. John´s college.

Fig. 8. Cathorops belizensis, holotype, USNM 286399, 175.0 mm SL (head in dorsal view). Belize, Belize City, mangrove swamps St. John´s college.

Fig. 9. Plot of standard length against dorsal-fin spine length, for Cathorops belizensis (holotype, filled triangle; paratypes, open triangle) and C. higuchii (holotype, open circle; paratypes, filled circle).

Fig. 10. Tooth plates of Cathorops belizensis. Abbreviations: atp - accessory tooth plates; Den - dentary; pe - posterior expansion; PMtp - premaxillary tooth plates.

Fig. 11. Distribution of marine and estuarine species of Cathorops in the CentralAmerican Caribbean.Cathorops belizensis (triangle) and C.higuchii(opensquare,holotype andsome paratypes;filled square,otherparatypes).Somesymbolsrepresent morethanone locality or lot ofspecimens (from www.aquarius.geomar.de).