Herichthys pantostictus (Taylor & Miller 1983)

Maza-Benignos, Mauricio De La & Lozano-Vilano, Ma. De Lourdes, 2013, Description of three new species of the genus Herichthys (Perciformes: Cichlidae) from eastern Mexico, with redescription of H. labridens, H. steindachneri, and H. pantostictus, Zootaxa 3734 (2), pp. 101-129 : 106-109

Herichthys pantostictus (Taylor & Miller 1983)

Figures 4 , 5 , and 15; Tables 4 and 5

Holotype. UMMZ 207699 (1: 79.5 mm SL, nongravid female) Laguna de Chairel near Tampico, México, R.M. y J.H. Darnell y E. Liner, December 29, 1952.

Material examined. Eighty-one specimens, 34–126.9 mm SL. Tamaulipas: UANL 17428 (13: 55.7–89.8 mm SL), Ojito de Jaumave, Lat. 23.933, Long. −100.05, 778 masl, Mauricio de la Maza Benignos (MMB), February 25, 2006; UANL 17431 (6: 39.4–73.9 mm SL), Guayalejo, Lat. 23.665, Long. −100.223, 568 masl, MMB, February 22, 2006; UANL 17473 (12: 39.3–63.6 mm SL), Río Mante, Lat. 22.73071667, Long. −98.994, 80 masl, MMB, May 0 9, 2006; UANL 17477, (10: 45.4–91.2 mm SL), Canal Mante, Lat. 22.717, Long. −98.9902, 82 masl, MMB May 0 9, 2006; UANL 17480 (6: 62.6–104 mm SL), El Encino, Lat. 23.13 Long. −99.617, 119 masl, MMB, May13, 2006; UANL 14685 (6: 34–62.4 mm SL), Laguna de la Puerta, 12 km northwest (NW) of Tampico on Hwy 100, SCB, December 29, 1964; Veracruz: UANL 17443 (5: 55.2–76.7 mm SL), Naranjos, Lat. 22.228, Long. −98.605, 48 masl, MMB, March 17, 2006; UANL 17511 (1: 126.9 mm SL), Platón Sánchez, Lat. 21.295, Long. −98.364, 55 masl, MMB, June 30, 2006; UANL 17513 (22: 62–70.4 mm SL), Naranjos, Lat. 22.228, Long. −98.605, 48 masl, MMB, July 1, 2006.

Diagnosis. Distinguished using the following combination of characters: shallow cheeks (mean 28%, SD 3%), large eye diameter (26%, SD 2% HL). In live fish the ground color is olive brown, but in preservation the body is brown with lighter color in the flanks. Head and dorsal areas dark; ventral areas light brown or whitish. Lower pharyngeal plate moderately stout and broad; indentation type polymorphic with 2 rows of 6–7 combined enlargedconic or medium-sized molariform teeth, increasing in size posteriorly, flanking the midline. Indentation type polymorphic; <20 conic and enlarged teeth along the posterior margin. Coastal and lagoon populations (i.e., Chairel and Rio Tigre) as well as many river populations have the entire body covered with dark dots placed at the base of the scales, darker and less marked on edges, except for the abdomen and venter of head. Dots show irregular rows in the body area.

Description. Derived from sexually mature specimens> 39 mm SL. Morphometric and meristic data are summarized in Tables 4 and 5. Species is polymorphic throughout its range; body elongated, depth, 36%–44% SL (mean 40%, SD 2%); head long, 36%–39% (mean 37%, SD 1%) SL; caudal peduncle, shallow, 14%–17% (mean 15%, SD 1%) SL. Predorsal contour steep and non-acute, curved out before the eye, forehead inconspicuous, and nuchal hump absent; dorsal and ventral contours straight to moderately convex with a moderate slope; mouth terminal and pointed; frenum weakly developed or absent. Dorsal fin XVI–XVII (mode XVI, freq 45%), 9–11 (mode 11, freq 35%); fin set forward of the opercle (intersects between the 1st and 3rd rays); depressed fin short, tip rarely expands beyond the anterior 3rd of the caudal fin. Anal fin V–VI (modeVI, freq 70%), 8–10 (mode 8, freq 70%); scales in longitudinal series 28–31 (mode 30, freq 50%). Anterior teeth regularly set, well-spaced, conic, unicuspid, strongly recurved, and pointed, with erect implantation; upper jaw with a pair of well-developed recurved fangs that are reddish in color. Lower jaw with 2nd, less-developed, pair of recurved fangs; 15–22 teeth in outer series of the premaxilla, 6–8 regularly set of acutely pointed, caniniform frontal teeth with moderately stout necks; lateral and posterior teeth small, non-caniniform, and irregularly set. Lower jaw with 2–3 rows of teeth; upper jaw with 3 rows of teeth; posterior rows of diminutive, irregularly set, and hardly visible teeth. Lower pharyngeal plate moderately stout and broad; indentation type polymorphic with moderately robust, lightly pigmented molars in some populations (i.e., Guayalejo) and enlarged, conic-flattened to moderately pointed and non-enlarged pigmented teeth in others (i.e., Tamiahua); 2 rows of 6–7 medium-sized enlarged conic teeth or molars increasing posteriorly in size; molarization flanking midline. Conic teeth along posterior margin conic and numbering 18–20. Stomach robust-walled, moderately saccular (16.42% of SL), rugged with longitudinal folds, and adhered at its anterodorsal section to a well-elongated, elastic, smooth caecum (27% of SL). Gut-coiling pattern with a double medial loop; secondary loop projecting away and passing under the gut. Peritoneum uniformly dark.

Coloration in preservative. Body brown, lighter on flanks. Head and dorsal areas dark; ventral areas light brown or whitish. Coastal forms and some lotic populations and individuals with bodies entirely covered with dots, except for the belly and underside of the head. Caudal, soft dorsal, and anal fins marked with streaks. Patterns along the flanks vary between populations from a faint discontinuous horizontal stripe to 3–5 irregularly formed blotches and a dark spot at the base of the caudal fin. Markings may be faint or completely lacking in older adults.

Live colors. Body olive brown; pectoral, caudal, and soft sections of dorsal and anal fins tan to light orange. Inter-radial membranes of dorsal and anal soft fins and caudal fin with dots and streaks, all centered on basal areas, particularly in spiny sections. Coastal and lagoon populations (i.e., Chairel and Rio Tigre), as well as many river populations, of H. pantostictus with entire body covered with dark dots at bases of scales; dots bigger and less marked at scale edges, except for abdomen and ventral region of the head. Dots are in irregular rows along body; other river populations (i.e., most Tamiahua, few Guayalejo, and none of the Panuco lotic populations) with few to no dots on flanks. All populations with a small, red–purple mark on axil of pectoral fin.

Breeding pigmentation. As noted by Salazar-Gonzáles (2007), breeding pigmentation varies between populations. Populations of Tamaulipas, including those from Guayalejo, Mante, Jaumave, and El Encino, develop darkening over anteroventral and posterior halves (regions) of the body. This forms a continuum that is interrupted by a 70°-angled vertical, pale area up the side and across the flank. The pale area begins anterior to the midsection of the abdomen, extends posteriorly to become horizontal with the hypural fan, and ends frontal to the anal fin base at 1/3rd the distance between the anal and pectoral fin origins. Populations of San Luis Potosí and Veracruz, including Tampaón and Platón Sánchez, develop darkening over the anteroventral and posterior halves (regions) of the body, separated by a pale area with a frontal point of origin halfway between anal and pectoral fin origins and up the side at 90° until it merges with the dorsal pale section; the posterior point of origin of the pale area begins at the midpoint of the spiny anal fin base and extends up the side at 100° to merge with the dorsal pale section. Darkening on the posterior half does not reach the dorsal contour anterior to the interception of the dorsal fin base with the caudal peduncle.

Geographical distribution. Río Tigre in Tamaulipas (San Andrés lagoon system), the Rio Naranjos in Veracruz (the Tamiahua lagoon system), coastal lagoons of Tampico, including Chairel, the Tamesí-Guayalejo subbasin from Jaumave Spring; The western limit of the species is the Rio Pánuco basin, excluding the Rio Verde valley, Media Luna, “Rio El Salto,” “Rio Gallinas,” and the headwaters of the Rio Moctezuma in the states of Hidalgo and Queretaro.

Habitat and associates. Herichthys pantostictus is sympatric with H. carpintis throughout most of its range, except in some high elevation sites such as Jaumave spring, Tamaulipas, where it shares its habitat with Xiphophorus sp. cf. variatus and Astyanax mexicanus , among other species. It prospers in habitats that range from turbid coastal lagoon systems with a muddy substrate to clear running waters and springs with rocky or sandy substrate. Stomach contents include detritus (10%), filamentous algae (80%), and snails (10%).

Vernacular names. Mojarra de Chairel, Chairel cichlid.

Geographic variants. Herichthys pantostictus is composed of a number of parapatric populations inhabiting the lower Panuco and the Rio Tamesí basins as well as tributaries to the adjacent Tamiahua and San Andrés lagoon systems. The species displays geographic variation in morphometric, meristic, and breeding pigmentation as observed by Salazar-Gonzáles (2007). H. pantostictus is parapatric with H. labridens and possibly H. molango sp. nov. Geographic variation in H. pantostictus is the most conspicuous between coastal lagoon forms and riverine forms of the Rio Tamesí-Guayalejo and Rio Panuco and their tributaries. River forms are generally more elongated than lagoon forms.

Conservation status. Not listed in NORMA Oficial Mexicana NOM-059-ECOL-2010 or on the IUCN Red List of Threatened Species 2009. Herichthys pantostictus appears to be stable throughout most of its range, except in the coastal lagoon areas where it appears scarce.

Remarks. This species was described by Taylor & Miller (1983) as Cichlasoma pantostictus from type locality of Laguna de Chairel (Tampico), and a population in the Rio Sabinas (the Tamesí-Guayalejo river system in Tamaulipas). Specimens can be described as having the entire body covered by small dark dots, except for the belly and ventral surface of the head. While lentic populations of H. pantostictus show the “entirely dotted” trait, which is a key to distinguishing between H. pantostictus and H. labridens according to Taylor & Miller (1983), many riverine populations and individuals are not entirely dotted. It is possible that the geographic distribution of the trait drove Taylor & Miller (1983) to erroneously conclude that an “entirely dotted pattern” is key to separating H. pantostictus from H. labridens and that H. pantostictus were sympatric or parapatric with H. labridens of the Guayalejo, Sabinas at Gómez Farías, Ojo de Jaumave, Río Tigre, and Río Mante. Hulsey et al. (2004) recovered H. pantostictus of Rio Tamesí, Rio Guayalejo, and Rio Tigre as sister taxa to a clade shared with H. pame sp. nov. of Rio Tamasopo and H. steindachneri .

Figures

FIGURE 4. Herichthys pantostictus (Taylor & Miller 1983) collected from Rio Naranjos in the Tamiahua lagoon system (~ 95 mm TL).

FIGURE 5. UANL 14685 Herichthys pantostictus collected from Laguna la Puerta (Tampico), Tamaulipas (62.4 mm SL). Mauricio De la Maza-Benignos, Figures 6 – 7.