Ariopsis gilberti
Creators: name: Marceniuk, Alexandre P.
name: Acero, Arturo
name: Cooke, Richard
name: Betancur-R, Ricardo
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Siluriformes
Ariidae
Ariopsis
Ariopsis gilberti

description: Ariopsis gilberti (Jordan & Williams, 1895)
Tete Sea Catfish (English)
Figure 12 and 13, Tables 2–4 and 8.
Galeichthys gilberti Jordan & Williams, 1895:395, Pl. 26. Type locality: Upper part of Astillero at Mazatlán, Sinaloa, western Mexico. Holotype: USNM 29213; Paratypes: BMNH 1895.5.27.244–246 (3); CAS-SU 1667 (2), 11666–68 (1, 1, 1); USNM 28161 (1, missing), 28189 (1), 28210 (1, missing), 28213 (1, missing), 28221 (2, missing), 28232 (1), 28276 (1), 28304 (1); ZMB 14043 (1).
Ariopsis seemanni (non Günther, 1864), Kailola & Bussing, 1995; Castro Aguirre et al., 1999: 155–156.
Material examined. Type specimens: Holotype, USNM 29213 (1, 291 mm SL), Mexico, Sinaloa, upper part of Astillero at Mazatlán; Paratype, USNM 28232 (1, 152, mm SL), USNM 28276 (1, 215 mm SL), USNM 28304 (1, 161 mm SL), all collected with the Holotype. Non-type specimens: LACM W58–32 (9, 211– 247 mm SL), Mexico, Nayarit, San Blas; UA 68–124 (1), Mexico, Nayarit, Punta Novillero; UA 69–49–3 (3), Mexico, Nayarit, San Blas, beach in front of village; UA 71–64–1 (11), Mexico, Nayarit, Ensenada Jaltemba, Rincón de La Guayabita (=just south of La Peñita).
Diagnosis. Ariopsis gilberti can be differentiated from its congeners as follows: from A. assimilis, from Mexico (Quintana Roo) to Honduras (Caribbean), by the presence of 19–20 gill rakers on the first gill arch (vs. 14– 18, Table 3), osseous medial groove present (vs. absent; Figs. 3 and 13), fleshy medial groove of neurocranium conspicuous and very long, always surpassing the posterior margin of eyes (vs. conspicuous or inconspicuous, but never surpassing posterior margin of eyes, Figs. 4 and 13), lateral margin of sphenotic notched, narrower medially than anteriorly (vs. straight, as wide medially as anteriorly, Figs. 3 and 13); from A. canteri, from Colombian Caribbean, by the presence of an osseous medial groove (vs. absent; Figs. 3 and 13), lateral margin of sphenotic notched, narrower medially than anteriorly (vs. straight, as wide medially as anteriorly, Figs. 3 and 13); from A. felis, from Massachusetts (US) to Yucatán in Mexico (Caribbean), by the presence of 40–42 gill rakers on the first and second gill arches (vs. 29–32), pterotic lateral margin markedly convex, sometimes angled (vs. smoothly convex, Figs. 3 and 13); from A. guatemalensis, from Mexico to Costa Rica (EP), by the presence of 40–42 rakers on the first and second gill arches (vs. 31–39), its smaller mouth 10.7–12.3% SL (vs. 13.0–15.2% SL), closer anterior nostrils 5.5–6.5% SL (vs. 7.1–8.6% SL), closer posterior nostrils 4.9–6.7% SL (vs. 7.2–8.7% SL), cephalic shield narrower in the frontal area 8.3–9.8% SL (vs. 10.0–11.5% SL), cephalic shield narrower in the lateral ethmoid area 12.5–14.0% SL (vs. 14.3–15.3% SL), mesethmoid median portion narrow (vs. wide, Fig. 3), mesethmoid medial notch narrow and deep (vs. large and shallow, Fig. 3), osseous medial groove present (vs. absent; Figs. 3 and 13), fleshy medial groove of neurocranium conspicuous and very long, always surpassing the posterior margin of eyes (vs. conspicuous or inconspicuous, but never surpassing posterior margin of eyes, Figs. 4 and 13), lateral margin of sphenotic notched, narrower medially than anteriorly (vs. straight, as wide medially as anteriorly, Figs. 3 and 13); from A. jimenezi, from Archipiélago de Las Perlas in Panama (EP), by the presence of 40–42 gill rakers on the first and second gill arches (vs. 29–34), external posterior branch of lateral ethmoid columnar and thin (vs. depressed and thick, Fig. 3) fenestra delimited by mesethmoid and lateral ethmoid conspicuous (vs. inconspicuous, Fig. 3), pterotic lateral margin markedly convex, sometimes angled (vs. smoothly convex, Figs. 3 and 13); from A. seemanni, from El Salvador to Panama (EP), by the presence of 40–42 gill rakers on the first and second gill arches (vs. 30–36), fleshy medial groove of neurocranium conspicuous and very long, always surpassing the posterior margin of eyes (vs. conspicuous or inconspicuous, but never surpassing posterior margin of eyes, Figs. 4 and 13); from A. simonsi, from Colombia to Peru (EP), by the presence of 40–42 gill rakers on the first and second gill arches (vs. 28–37), fleshy medial groove of neurocranium conspicuous and very long, always surpassing the posterior margin of eyes (vs. conspicuous or inconspicuous, but never surpassing posterior margin of eyes, Figs. 4 and 13), lateral margin of sphenotic notched, narrower medially than anteriorly (vs. straight, as wide medially as anteriorly, Figs. 3 and 13).
Description. Morphometrics and meristics summarized in Tables 2–4, 8. Head relatively short, wide and high, especially depressed at lateral ethmoid and frontal area, profile slightly elevated posteriorly, straight from mesethmoid to parietosupraoccipital. Snout rounded and moderately long. Anterior nostril rounded, with fleshy edge, posterior nostril covered by flap of skin, nostrils moderately separated and distant from orbit, not connected by fleshy furrow. Eye lateral, relatively large. Eyes moderately separated. Three pairs of long teretiform barbels; maxillary barbel surpassing or not membranous portion of operculum, lateral and mesial mental barbel not reaching posterior margin of gill membrane. Osseous bridge formed by lateral ethmoid and frontal moderately long and slender, delimiting a fenestra little evident under the skin. Cephalic shield exposed, moderately long and relatively narrow on supracleithrum, lateral ethmoid and frontal areas, with thick granulation, forming distinct patterns from eyes to parietosupraoccipital procces. Fleshy portion of dorsomedial groove of neurocranium, affixed to anterior cranial fontanel, long and conspicuous, reaching eyes. Lateral margin of sphenotic notched, narrower medially than anteriorly. Pterotic lateral margin markedly convex, sometimes angled. Parietosupraoccipital keeled, triangular, with straight lateral margins converging posteriorly, relatively short and moderately wide at posterior portion, with posterior margin convex. Nuchal plate crescent-shaped, conspicuously granulated dorsally, moderately long and narrow. Mouth subterminal, moderately large, with lips moderately thick and lower jaw arched. Vomerine tooth plates rounded. One pair of accessory tooth plates ovate, with sharp teeth. Premaxilla rectangular transversally, moderately long and wide, with sharp teeth. Dentary with eyebrow-shaped patch of teeth, separated at midline with sharp teeth. Gill membranes fused, attached to isthmus. Nineteen to 20 acicular gill rakers on first arch, 21–22 spike-shaped gill rakers on second arch and rakers present on posterior margin of all gill arches.
Body wider than its height at pectoral girdle area, progressively compressed from pectoral to caudal peduncle, ventrally flattened from pectoral girdle to anal origin. Lateral line sloping ventrally on anterior one-third, extending posteriorly to caudal peduncle, bending abruptly onto dorsal lobe of caudal. Dorsal spine relatively short and thick, shorter than pectoral spine; anterior margin granulated on basal two thirds, with weak serrations on distal third; posterior margin smooth on basal third, distal third with weak serrations. Seven dorsal soft rays. Pectoral spine relatively short and thick; two-thirds of anterior margin weakly granulated, with weak serrationson distal third; posterior margin straight on basal one-fourth, distal three-fourths with serrations. Nine to ten pectoral soft rays. Posterior process of cleithrum triangular smooth to rugose, slightly visible. Pelvic fin deep and large at base, with six rays, and well-developed fleshy protuberances in adult females. Adipose fin low, with base moderately long, shorter than anal base. Anal fin moderately high and long at base, with 17–19 rays and ventral profile convex. Caudal peduncle moderately high. Caudal fin forked, dorsal and ventral lobes relatively long, dorsal lobe somewhat longer than ventral lobe, slightly pointed.
Maximum length: Maximum size unknown; largest specimen examined 291 mm SL.
Coloration in alcohol. Head and body bluish above, whitish below; dorsal surfaces of pelvic proximally black, distally lighter; anal dark, distal tips lighter; caudal grayish to blackish (Fig. 12).
Sexual dimorphism. Only females have well-developed fleshy protuberances or pads in basal portion of pelvics, especially during reproductive season. Vomerine tooth patches and accessory tooth patches not observed directly, but possibly showing same variation described for A. canteri and A. jimenezi.
Distribution and habitat. The EP Ariopsis gilberti occurs in estuarine and marine waters of Mexico, from Laguna de San Juan (Sonora) to Mar Muerto (Chiapas, Gulf of Tehuantepec; Fig. 5).
Remarks. Ariopsis gilberti was described from a well represented type series collected at the upper part of Astillero in Mazatlán (Sinaloa, Mexico; Figs. 12 and 13) (Jordan & Williams, in Jordan 1895). Jordan & Evermann (1896) mentioned the species as being common in Sinaloa, and by far the most abundant species in Mazatlán. Apparently Boulenger (1898) was the first to propose that the species is a junior synonym of A. seemanni. Regan (1906 –1908) examined the type series of A. gilberti and backed its synonimization, a condition accepted by Kailola & Bussing (1995). No other authors questioned the clear differences in gill-raker counts (most congeners have less than 40 gill-rakers on the first and second gill arches combined, except for A. canteri and A simonsi) or any other morphological feature differentiating the species (see diagnosis).
description: Published as part of Marceniuk, Alexandre P., Acero, Arturo, Cooke, Richard & Betancur-R, Ricardo, 2017, Taxonomic revision of the New World genus Ariopsis Gill (Siluriformes: Ariidae), with description of two new species, pp. 1-42 in Zootaxa 4290 (1) on pages 19-22, DOI: 10.11646/zootaxa.4290.1.1, http://zenodo.org/record/828843