Acanthochitona exquisita (Pilsbry, 1893)

Reyes-Gómez, Adriana, Vargas-Ponce, Ofelia, Galván-Villa, Cristian, Salgado-Barragán, José, Esqueda-González, Ma. Del Carmen & Ríos-Jara, Eduardo, 2023, Inventory of chiton species (Polyplacophora) from the rocky intertidal of the Northern Gulf of California, with an illustrated taxonomic key, Zootaxa 5296 (2), pp. 147-178 : 167-169

Acanthochitona exquisita (Pilsbry, 1893)

( Figures 3F , 10G–L )

Acanthochites exquisitus Pilsbry, 1893: 44–47 . Chresonymy and synonymy in Watters (1990).

Type material. Lectotype, designated by Watters (1990), ANSP 349332 .

Type locality. Bahía Las Ánimas , Baja California (BC), México.

Material examined. Twenty– six specimens, BL 8.3–20.9 mm.

Habitat. On large to medium–sized semi–submerged rocks, mainly on rough surfaces with coralline algae, either filamentous, crusty, green, brown or red.

Remarks. Acanthochitona exquisita has a sculpture of pustules with one aesthete on the center of its base ( Figs 10J, K ). Intermediate valves with sub–triangular tegmentum and jugal area smooth ( Fig. 10H ). Major lateral radular tooth tricuspid, minor lateral teeth small and short, very reduced; the central tooth appears as a rectangular long plate ( Fig. 10L ). This species can reach body lengths between 25 and 34 mm and is considered a large species within the genus.

Figures

FIGURE 3. Chiton species obtained from the Northern Gulf of California. A. Dorsal and lateral view of Dendrochiton lirulatus CUCBACM 00479. B. Dorsal view of Lepidochitona beanii CUCBACM 00486. C. Dorsal and lateral view of Nutallina crossota CUCBACM 00488. D. Dorsal view of Chiton virgulatus CUCBACM 00491. E. Dorsal view of Acanthochitona avicula CUCBACM 00494. F. Dorsal view of Acanthochitona exquisita CUCBACM 00497.

FIGURE 10. Scanning electron microscope images (A–F) of Acanthochitona avicula CUCBACM 00494. A. Dorsal view of head valve. B. Dorsal view of intermediate valve IV. C. Dorsal view of tail valve. D. Dorsal view of Valve IV detail of pustules. E. Portion of girdle, shows the dorsal girdle spicules. F. Portion of radula, show the central, minor and major lateral teeth. Acanthochitona exquisita CUCBACM 00497 (G–L). G. Dorsal view of head valve. H. Dorsal view of intermediate valve IV. I. Dorsal view of tail valve. J. Dorsal view of valve pustules of valve IV. K. Magnification of valve IV pustules. L. Radular teeth.