Chiton virgulatus Sowerby, 1840

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 : 165-166

Chiton virgulatus Sowerby, 1840

( Figures 3D , 7L )

Chiton virgulatus Sowerby, 1840: 824 . Chresonymy and synonymy in Bullock (1988).

Type material. According to Bullock (1988), the holotype is held in BMNH but Bullock mentioned that it was not found .

Type locality. According to Bullock (1988) at Bahía Kino, Sonora, México .

Material examined. Sixty– two specimens, BL 3.9–47.8 mm.

Habitat. In the intertidal, on large rocks with brown and red crusty algae patches. The rocks were found in shallow waters in an exposed, semi–dry rocky area; the chitons were collected on the rocks buried in the wet sand.

Remarks. Chiton virgulatus has radial, bifurcated, narrow ribs ( Fig. 3D ) on the head and tail valves and the lateral areas of the intermediate valves. Radula with unicuspid major lateral teeth, minor lateral tooth of about the same length as the central tooth ( Fig. 7L ).

Thorpe (1971) and Abbott (1974) agreed that Chiton stokesii and C. virgulatus are sympatric in the southern Mexican Tropical Pacific (MTP). Bullock (1985) and Reyes–Gómez (2016) rectified this assumption based on their expeditions in this region and the study of additional material. They found that C. virgulatus is restricted to the Gulf of California and C. stokesii to Central America. Chiton virgulatus is endemic to the Gulf of California and, contrary to other species of the genus Chiton present in the Mexican Pacific, it is characterized by a longitudinal and bifurcated tegmental sculpture.

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 7. A–F. Scanning electron microscope images of Lepidozona subtilis CUCBACM 00475. A. Dorsal view of head valve. B. Dorsal view of half of intermediate valve IV. C. Dorsal view of tail valve. D. Valve IV aesthetes’ detail of intermediate area. E, F. Radular teeth details. G–K. Scanning electron microscope images of Callistochiton elenensis CUCBACM 00476. G. Dorsal view of head valve. H. Dorsal view of half of intermediate valve IV. I. Dorsal view of tail valve. J. Dorsal girdle scales detail. K. Radular teeth. L. Radular teeth of Chiton virgulatus CUCBACM 00491 of Chiton virgulatus CUCBACM 00491.