Herichthys pantostictus (Taylor & Miller, 1983)

Mejía, Omar, Pérez-Miranda, Fabián, León-Romero, Yatzil, Soto-Galera, Eduardo & Luna, Efraín de, 2015, Morphometric variation of the Herichthys bartoni (Bean, 1892) species group (Teleostei: Cichlidae): How many species comprise H. labridens (Pellegrin, 1903)?, Neotropical Ichthyology 13 (1), pp. 61-76 : 72-73

Herichthys pantostictus (Taylor & Miller, 1983)

Cichlasoma pantostictus Taylor & Miller, 1983: 1-24 [original description]. - Miller et al., 2005: 402-403 [catalog].

Herichthys pantostictus . -León-Romero et al., 2012: 1021-1026 [phylogenetic analysis].

De la Maza-Benignos & Lozano-Vilano, 2013: 117-119 [redescription].

Nosferatu pantostictus . -De la Maza-Benignos et al., 2014: in press [citation].

Diagnosis. There are no unique autapomorphies that allow us to distinguish Herichthys pantostictus from the rest of the species in the group. Most of the specimens of this species showed brown to black dots in the head and the body, the latter being larger in size, although some populations might lack this trait. Some specimens of H. molango might also show dots in the body, but in this species, the dots are disperse and usually red. This species differs slightly from its sister taxon H. molango in its body shape, according to geometric morphometrics, and its geographic distribution (see below).

Description. Morphometric and meristic data are summarized in Tables 3-4.

Color in life. Body gray to pale yellow, sometimes vanishing to white, dark blotches extending from posterior end of the opercle to the caudal fin, sometimes forming four to six vertical bars. Head densely covered by brown or black small dots that extend from the tip of premaxilla to the basis of the dorsal fin. Most of the specimens with dots in the body that are bigger than those found in the head, fins black to yellow, dorsal, anal and caudal fin usually with small brown blotches at its base, red to purple axial mark present.

Color in alcohol. Body dark gray to brown vanishing to the ventral region, black blotches, fins white to yellow, axial mark could be absent.

Distribution. Costal lagoons and rivers in the south of Tamaulipas and North of Veracruz.

Remarks. According to Taylor & Miller (1983; Tables 1,3), this species can be distinguished from H. labridens because the entire body is covered with small dark brown spots and by longer basal lengths of dorsal and anal fins and a shorter caudal peduncle. If we compare only the specimens from río Verde and exclude the non-río Verde specimens from the work of Taylor & Miller (1983), that could correspond to another species, we can state that in H. labridens , the dorsal base length ranges from 53.6% to 58.3%, the anal base length ranges from 21.2% to 24.8% and the caudal peduncle ranges from 14.4% to 17.3%. Conversely, in the original material examined by Taylor & Miller (1983), in H. pantostictus , the dorsal base length ranges from 54.3% to 60.6%, the anal base length ranges from 23.3% to 27.1% and the caudal peduncle ranges from 13.5% to 15.6%. The above-mentioned proportions were similar to those found in this study (Table 3); however, the overlap in the minimum and maximum values precludes their use as diagnostic characters. In a recent redescription of the species, De la Maza-Benignos & Lozano-Vilano (2013) state that in most of the coastal and lagoon populations, the entire body is covered with dark dots, although some riverine populations lack this trait; they also state that shallow cheeks and the large eye diameter allow the differentiation of these species from the rest. Nevertheless, a close inspection of their table 4 again reveals a high overlap of these measurements with those from other species, so there is no diagnostic character that allows the differentiation of H. pantostictus from the rest of the species. The same is true for the number and shape of the teeth in the midline of the lower pharyngeal plate. According to De la Maza-Benignos & Lozano-Vilano (2013), H. pantostictus can be distinguished from the rest of the species by having 6 to 7 teeth flanking the midline on each side, conic to midsize molariform and increasing in side posteriorly. Similar results were found in the specimens that we reviewed, except the number ranged from 6 to 8 teeth. Nevertheless, the same pattern was found in the specimens classified in this study as H. cf. labriden s (= H. molango ) from Huejutla, Hidalgo, Tamazunchale, San Luis Potosí and Jaumave, Tamaulipas and even in H. molango (data not shown). In the map depicted in Fig. 1 , we include a single locality of H. cf. pantostictus from río Axtla, San Luis Potosí because this specimen presents dark spots in the body, in the same way, we assess specimens from the two localities of Jaumave and río Mante, Tamaulipas as H. cf. labridens (= H. molango ) due to the lack of dark spots on the body. The above facts led us to question the existence of H. pantostictus and H. molango (including H. cf. labridens ) as two different species, primarily because of the absence of diagnostic characters. Nevertheless, despite these findings, in the present study, 81% of the individuals identified as H. pantostictus were correctly classified in the DFA of the morphometric data adjusted as proportions ( Table 1, Fig. 4 ). In addition, this species presents a body shape that is slightly different from that of their sister taxa H. molango (including H. cf. labridens ) ( Fig. 5 ) despite their shared DNA haplotypes. In such a way, H. pantostictus and H. molango could be distinguished in part by their geographic distribution, with the former distributed in South of Tamaulipas and North of Veracruz and the latter distributed in the South of San Luis Potosí and North of Hidalgo.

Material examined. Mexico: Río sobre la carretera Ocampo-el Limón, Tamps. ENCB-P P5988, 2, 86.0- 123.2 mm SL, río Guayalejo, Tamps. ENCB-P P5990, 7, 51.9-95.5 mm SL, río Mante, Tamps. P5991, 6, 72.7-112.7 mm SL, río Sabinas, Tamps. ENCB-P P5997, 3, 57.9-114.3 mm SL, Arroyo en el Encino, Tamps. ENCB-P P5999, 15, 58.4-116.6 mm SL, río Guayalejo, Tamps. ENCB-P P6000, 3, 65.7-86.2 mm SL, río en Nuevo Morelos, Tamps. ENCB-P P6005, 2, 118.6- 140.9 mm SL, rió Tamozus, Ver. ENCB-P P6105, 5, 55.0- 88.2 mm SL.

Figures

Fig. 1. Geographic distribution of the species included in the Herichthys bartoni group. Note: The species H. pratinus was not included in this work.

Fig. 4. Canonical variance analysis derived from the discriminant function analysis of the species included in the Herichthys bartoni species group. A) Meristic data B) Morphometric data adjusted by the method of Mossimann C) Morphometric data adjusted as proportions. Symbology: Blue: H. bartoni, Red: H. cf. labridens, Green: H. labridens, Violet: H. molango, Black: H. pame, Gray: H. pantostictus, Brown: H. steindachneri.

Fig. 5. Canonical variance analysis derived from the geometric morphometric analysis of the species included in the Herichthys bartoni species group. A) canonical variate 1 and 2 for the head, B) canonical variate 2 and 3 for the head, C) canonical variate 1 and 2 for the body, D) canonical variate 2 and 3 for the body. Symbology: Blue: H. bartoni, Red: H. cf. labridens, Green: H. labridens, Violet: H. molango, Black: H. pame, Gray: H. pantostictus, Brown: H. steindachneri.