Cathorops (Cathorops) kailolae, 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) kailolae , new species Figs. 16 and 17

Cathorops aguadulce (non Meek); Castro-Aguirre et al., 1999 (in part): 148-149 [remarks and distribution, Mexico and Guatemala, from?río Grijalva to río Polochic]; Miller et al., 2005 (in part): 170 [description and distribution, Mexico and Guatemala,?río Grijalva, río Usumacinta, and lago Izabal basins]; Betancur-R. & Willink, 2007 (in part) [key features and distribution, Mexico and Guatemala,río Usumacinta and lago Izabal basins]; Betancur-R. et al., 2007:349 [only name].

Holotype. USNM 134330 , 181.0 mm SL (male), Guatemala, lago Izabal, embayment about 3 mi. W of El Estor , 8-9 Apr 1946, R. R. Miller and A. D. Holloway.

Paratypes. USNM 385739 , 10 (5, 145.0-214.0 mm SL), collected with holotype ; AMNH 35074 , 7 (3, 106.0-135.0 mm SL), Guatemala, Izabal, río Cienaga, 1 kilometer above mouth into río Dulce , 11 Apr 1974, R.M. Bailey et al .; AUM 19407, 6 (5, 112.0-159.0 mm SL), Guatemala, Izabal, lago Izabal, shore at beach off Finca Carolina ; UF 35320 , 12 (4, 51.0-119.0 mm SL), Guatemala, Izabal, lago Izabal, off Finca Carolina , 25 Jul 1979, C. L. Dyer and A. E. Limon .

Non-type specimens. AUM 32198, 3 , 161- 166 mm SL, Guatemala, Petén, mouths of río San Juan and río Pucté, río La Pasión , río Usumacinta basin; ANSP 142725, 1, 215.0 mm SL, Guatemala, Petén, near Sayaxche , río Usumacinta basin ; UMMZ 188018 , 3 , 168.0-276.0 mm SL (1, 276.0 mm SL), Guatemala, Petén, Arroyo Tamarindo 0.5 km above mouth in Laguna Petexbatum, above jct with Arroyo Aquateca, 16º24’15’’N, 90º11’20’’W, río Usumacinta basin . ECO-SC 4270 , 1 , 198.0 mm SL, Mexico, Chiapas, MontesAzules, Selva Lacandona, Río Usumacinta basin ; ECO-SC 4269 , 1 , 202.0 mm SL ; ECO-SC 4268 , 1 , 217.0 mm SL, Mexico, Chiapas, MontesAzules, Selva Lacandona, Río Usumacinta basin .

Diagnosis. Cathorops kailolae is distinguished from all congeners, except C. aguadulce , through the fleshy papillae intercalated with gill rakers on first two gill arches (vs. papillae absent in the remaining species, except in C. aguadulce ) ( Fig. 3 ), 14-16 gill rakers on first arch (vs. 17-23 in C. agassizii , 17-22 in C. arenatus , 19-20 in C. belizensis , 18-21 in C. higuchii , 37-40 in C. hypophthalmus , 20-24 in C. mapale , 17-21 in C. spixii , and 19-22 in C. tuyra ), and body width 17.7-19.7% SL (vs. 20.7-24.3% SL in C. arenatus , 20.5-23.5% SL in C. belizensis , 20.0-21.0% SL in C.

A. P. Marceniuk & R. Betancur-R. 37

dasycephalus , 20.3-22.5% SL in C. fuerthii , 20.0-22.4% SL in C. higuchii , 19.8-20.1% SL in C. hypophthalmus , 20.1-21.8% SL in C. mapale , 20.7-21.9% SL in C.manglarensis , and 20.3-23.7% SL in C. tuyra ).

Cathorops kailolae is distinguished from C. aguadulce by possessing a shorter snout (6.0-8.6 vs. 9.3-11.6% SL) ( Fig. 4 ), and shorter distance from tip of snout to dorsal-fin origin (33.1- 38.0 vs. 39.0-40.7% SL) ( Fig. 5 ). Cathorops kailolae also differs from C. belizensis in having a shorter distance between anterior nostrils (3.2-4.5 vs. 5.1-6.1% SL), shorter distance between posterior nostrils (4.1-5.3 vs. 5.9-7.6% SL), larger orbital diameter (4.6-6.6 vs. 3.6-4.4% SL), shorter interorbital distance (8.9-12.3 vs. 12.9-15.1% SL), longer dorsal-fin spine (19.3-24.9 vs. 15.9-17.6% SL), narrower mouth (8.1-10.0 vs. 10.0-13.2% SL), narrower premaxilla (4.3-5.4 vs. 6.3-11.9% SL), and longer lower lobe of caudal-fin (29.2-34.3 vs. 25.5-28.2% SL). Cathorops kailolae is further distinguished from C. higuchii in possessing a narrower supraoccipital process at posterior portion (1.9-2.6 vs. 2.7-3.3% SL), shorter accessory tooth plates (1.3-2.5 vs. 2.6-4.7% SL), narrower premaxilla (4.3-5.4 vs. 5.7-7.7% SL), and larger orbital diameter (4.6-6.6 vs. 3.3-4.4% SL). Cathorops kailolae can be additionally distinguished from C. mapale species group in possessing a shorter interorbital distance (8.9-12.3 vs. 12.6-15.0% SL), narrower cephalic shield at supracleithrum area (15.3-17.3 vs. 17.3-19.8% SL), shorter accessory tooth plates (1.3-2.5 vs. 2.7- 4.3% SL), and narrower premaxilla (4.3-5.4 vs. 5.7-7.7% SL). Cathorops kailolae is further distinguished from C. melanopus in possessing a longer snout (6.0-8.6 vs. 5.3-5.5% SL), longer distance from tip of snout to dorsal-fin origin (33.1-38.0 vs. 30.0- 32.6% SL), longer distance from tip of snout to pelvic-fin origin (50.4-52.6 vs. 46.2-49.1% SL), longer dorsal-fin spine (19.3-24.9 vs. 17.2-18.1% SL), and lower caudal peduncle (6.6-8.0 vs. 8.7- 9.0% SL).

Description. ( Tables 1 and 5). Head long and depressed, profile slightly convex at level of frontals and supraoccipital. Body broader rather than deeper on pectoral girdle area. Cephalic shield rugose, relatively short and narrow on lateral ethmoid, frontal, supracleithrum, and epioccipital areas. 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 long and narrow on posterior portion, profile straight. Nuchal plate crescent-shaped, moderate in size. Snout relatively long, rounded on transverse section. Anterior and posterior nostrils relatively close to one another. Eye lateral and large. Interorbital distance short, distance between nostrils and orbit relatively large. Maxillary barbel surpassing base of pectoral-fin spine or reaching half of spine, external mental barbel surpassing margin of gill membrane, internal mental barbel reaching margin of gill membrane.

Mouth small, lower jaw arched. Lips thick, lower lip thicker than upper lip. Vomerine tooth plates absent. One pair of accessory tooth plates, elongated and narrow, quite small and distant from each other. Accessory tooth plates with small and not numerous molariform teeth. Premaxilla relatively short and quite narrow. Dentary with no so pronounced posterior projection, with many sharp teeth on anterior portion and few small molariform teeth on posterior portion.

Soft pectoral-fin rays 9-10 (10). Pectoral-fin spine long and thick; anterior margin with few granules on basal two thirds, distal third with short serrations; posterior margin with straight basal fourth, distal three quarters with long and conspicuous serrations. Soft dorsal-fin rays 7. Dorsal-fin spine longer than pectoral-fin spine; anterior margin with few granules 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 high and relatively short at base, with 20-24 (22) rays. Upper and lower lobes of caudal fin long, upper lobe longer than lower lobe. Caudal peduncle relatively low.

Acicular gill rakers on first arch 14-16 (14), 4 or 5 (5) on upper limb, 9 to 11(9) on lower limb. Spike shaped gill rakers on second arch 13-16 (13), 4 or 5 (4) on upper limb, 9 to 11 (9) on lower limb. Mesial surfaces of all gill arches with developed gill rakers. Lateral and mesial surfaces of first and second gill arches with fleshy papillae intercalated with gill rakers, papillae more developed on second arch.

38 Revision of the ariid species of the genus Cathorops

Coloration in alcohol. Dorsal and lateral portions of head dark brown, ventrally light beige. Body with same dark brown color, progressively lighter towards lateral line and rather light beige under lateral line. Maxillary barbel dark, mental barbels light, fins dark especially towards edge.

Sexual dimorphism. Sexual dimorphism was observed in three females (145.0-214.0mm SL) and three males (145.0-210.0mm SL) with respect to the following morphological features ( Table 5). Head and anterior portion of body longer in males than in females, as evidenced by greater distances from tip of snout to dorsal-, pelvic-, and adipose-fin origins. Females with longer and broader accessory tooth plates, males with accessory plates more distant from one another and covered by epithelial tissue ( Fig. 18 ). Posterior expansion of dentary longer in females than in males ( Fig. 18 ). Pectoral-fin and dorsal-fin spines, pelvic fin, and upper lobe of caudal fin longer in females than in males. Males with longer anal-fin base than females. Body deeper in females than in males.

A. P. Marceniuk & R. Betancur-R. 39

Distribution. Material examined of Cathorops kailolae comes from the lago Izabal basin in Guatemala (type locality) and the río Usumacinta basin in Mexico and Guatemala ( Fig. 6 ). Because the main arm of the río Usumacinta flows into the río Grijalva near its mouth, the population reported by Miller et al. (2005, Map 6.144) from the río Grijalva is probably conspecific with C. kailolae , but this requires confirmation.This species inhabits chiefly freshwaters, but apparently also present in high salinities, as in laguna de Términos ( Miller et al., 2005).

Etymology. The species is name to honor Dr. Patricia J. Kailola, The University of the South Pacific, Suva, Fiji, for her enormous contribution to the systematics of the Ariidae .

Figures

Fig. 16. Cathorops kailolae, holotype, USNM 134330, 181.0 mm SL (body in lateral view). Guatemala, lago Izabal, embayment about 3 mi. W of El Estor.

Fig.3.Secondgillarchof(A)Cathoropsmelanopus(UMMZ197336, 188.0mmSL),and(B)C.kailolae(UMMZ186482,190.0mmSL). Lateralview.Abbreviations:GR - gillrakers;FP - fleshypapillae.

Fig. 4. Plot of standard length against snout length for Cathorops aguadulce (holotype, open circle; non-type specimens, filled circle) and C. kailolae (holotype, filled triangle; paratypes and non-type specimens, open triangle).

Fig. 5. Plot of standard length against distance from snout to dorsal fin for Cathorops aguadulce (holotype, open circle; nontype specimens, filled circle) and C. kailolae (holotype, filled triangle; paratypes and non-type specimens, open triangle).

Fig. 18. Tooth plates of Cathorops kailolae. Abbreviations: atp - accessory tooth plates; Den - dentary; pe - posterior expansion; PMtp - premaxillary tooth plates.

Fig. 6. Distribution of freshwater species of Cathorops in Mesoamerica. C. aguadulce [open square, holotype; filled square, non-types; hatched square, from Miller et al. (2005, Map 6.144)]; C. kailolae [open circle, holotype; filled circle, paratypes; gray circle, non-types; hatched circle, from Miller et al. (2005, Map 6.144)], and Cathorops melanopus (triangle). Some symbols represent more than one locality or lot of specimens (from www.aquarius.geomar.de).