Chaetopleura hanselmani (Ferreira, 1982)

Reyes-Gómez, Adriana, Flores-Garza, Rafael, Galeana-Rebolledo, Lizeth, Hernández-Vera, Gerardo, Galván-Villa, Cristian M., Torreblanca-Ramírez, Carmina, Flores-Rodríguez, Pedro, García-Ibañez, Sergio & Ríos-Jara, Eduardo, 2022, Intertidal chitons (Mollusca: Polyplacophora) from the rocky coastline of Guerrero, México, with the description of a new species, Zootaxa 5155 (4), pp. 451-492 : 456

Chaetopleura hanselmani (Ferreira, 1982)

Figures 2B , 4D–K , 5A–D

Distribution. From Mazatlán, México to Isla Lobos Afuera, Perú ( Ferreira 1982a).

Type specimens. Holotype CAS 017703 .

Type Locality. Isla Santa Cruz , Galapagos Islands .

Material examined. 20 specimens, maximum size of 11.8 mm long, 7.1 mm width. M (n=2); K (n=1); P (n=4); D (n=3); U (n=1); H (n=3); I (n=2); N (n=1); A (n=3).

Habitat. This species was commonly found below 3 m depth, attached to small rocks buried in sand. According to Kaas & Van Belle (1987) Chaetopleura hanselmani is distributed in intertidal. However, Reyes-Gómez et al. (2010) reported that C. hanselmani is mostly distributed in shallow subtidal since it was found at 7 m depth at Casa Mixteca, Oaxaca (e.g., CNMO 5247).

Adult specimens were found together with Callistoplax retusa , Callistochiton elenensis , and juveniles of Ischnochiton muscarius and Stenoplax limaciformis , on rocks with crustose algae.

Remarks. Ferreira (1982a: fig. 6) and Kaas & Van Belle (1987: fig. 33:1–12) described the holotype from Santa Cruz Island, Galápagos and provided figures of the radular teeth. When comparing Guerrero specimens to the holotype, we identified a few differences that could be significant with more study of material from the Galápagos islands. Those authors depicted the minor (5 th) lateral tooth anteriorly broad with wing-like edges, whereas this tooth of specimens from Guerrero lack this anterior widening and appear shorter. In addition, pustules of the lateral valve areas of the holotype were depicted to be arranged in rows that are symmetrically aligned, while specimens from Guerrero display pustules in a scattered pattern.

Figures

FIGURE 2. Dorsal view of the whole specimens that represent the analyzed species. A, Chaetopleura lurida, BL 27.48 x 15.70 mm, Majahua, Acapulco (CNMO 5229). B, Chaetopleura hanselmani, BL 11.02 x 7.16 mm, Tlacopanocha, Acapulco (CNMO 5804). Ischnochiton muscarius, C, BL 16.62 x 9.77 mm, Angosta, Acapulco (CNMO 5202); D, BL 15.12 x 9.55 mm, Barra de Potosí Protegida, Petatlán (CNMO 5338); E, BL 18.30 x 10.17 mm, Troncones, La Unión (CNMO 5327); F, BL 14.98 x 9.51 mm, La Barrita, Petatlán (CNMO 5315). G, Callistochiton elenensis, BL 12.32 x 7.76 mm, La Barrita, Petatlán (CNMO 5823). H, Callistoplax retusa, BL 20.41 x 9.68 mm, Parque de la Reina, Acapulco (CNMO 5185). Stenoplax limaciformis, I, BL 17.56 x 7.21 mm, Parque de la Reina, Acapulco (CNMO 5179); J, BL 20.12 x 9.15 mm, Tlacopanocha, Acapulco (CNMO 5208); K, BL 17.65 x 8.29 mm, Las Gatas, Zihuatanejo de Azueta (CNMO 5254); L, BL 19.78 x 9.84 mm, Isla Grande, Zihuatanejo de Azueta (UAGRO 0024). Chiton albolineatus, M, BL 23.84 x 14.63 mm, Piedra de Tlacoyunque, Tecpan de Galeana (CNMO 5337). Tonicia forbesii, BL 33.41 x 17.86 mm, Isla Grande, Zihuatanejo de Azueta (CNMO 5255). Acanthochitona arragonites, O, BL 8.80 x 5.2 mm, Las Salinas, Copala (CNMO 5267). Lepidochitona salvadorensis, P, BL 10.63 x 5.7 mm, Barra de Potosi Protegida, Zihuatanejo de Azueta (CNMO 5332).

FIGURE 4. Chaetopleura lurida, SEM images of a specimen BL 15.9 mm, A, girdle corneous hairs; B, girdle spicules; C, radular teeth. Chaetopleura hanselmani, BL 10.11 mm; valves in dorsal view, D, head valve; E, intermediate valve IV. Valves in ventral view, F, head valve; G, intermediate valve IV. SEM images of a specimen BL 10.9 mm; valves in dorsal view, H, head valve; I, intermediate valve IV; K, tail valve. J, valve IV in ventral view.

FIGURE 5. Chaetopleura hanselmani, SEM images of a specimen BL 10.9 mm; A, girdle spicules; B, detail of spicules ornamentation; C, radular teeth; D, detail of central and minor lateral teeth. Ischnochiton muscarius, disarticulated valves of a specimen BL 22.31 x 11.95 mm, Las Gatas, Zihuatanejo de Azueta, (CNMO 5183). Dorsal view of valves, E, head valve; F, intermediate valve IV; G, tail valve. Ventral view of valves, H, head valve; I, intermediate valve IV; J, tail valve. K, detail of girdle scales.