Bostrycapulus latebrus, Collin, 2005

Collin, Rachel, 2005, Development, phylogeny, and taxonomy of Bostrycapulus (Caenogastropoda: Calyptraeidae), an ancient cryptic radiation, Zoological Journal of the Linnean Society 144 (1), pp. 75-101 : 97-98

BOSTRYCAPULUS LATEBRUS SP. NOV.

Synonymy

Crepidula aculeata - Hoagland, 1977 [in part]: 364.

Crepidula cf. aculeata - Mexico. Collin, 2003a: 541– 593. Collin, 2003b: 618–640.

Holotype: FMNH 282358 , shell and ethanol-preserved soft parts. Shell illustrated in Figure 11 ; length = 15.0 mm, width = 11.9 mm, height = 4.1 mm. Frozen tissue is also deposited at the FMNH under the same lot number.

Type locality: just north of La Paz, Baja California Sur, Mexico, along the coast of Ensenada La Paz near El Comitán. Collected from rocks in the low intertidal zone.

Other material from the type locality: FMNH 282193 (paratype) , FMNH 282194 .

Diagnosis: B. latebrus can be distinguished from other species of Bostrycapulus by DNA sequence data and by its direct development from large eggs with embryos that retain larval features (unlike B. pritzkeri ). The shell morphology and anatomy of B. latebrus do not differ from that described above for B. aculeatus . Diagnostic DNA sequence differences distinguishing B. latebrus from all other Bostrycapulus species are in the following positions in the COI sequences submitted to GenBank (position 1 = position 1537 of the D. yakuba mitochondrial genome, GenBank # X03240 ): 3 (g), 108 (c), 144 (g), 192 (g), 243 (a), 270 (c), 306 (g), 327 (g), 423 (c), 522 (t).

Distribution: material whose identity can be verified as B. latebrus has only been collected near La Paz, Mexico. Shells that may be from this species occur commonly along the Pacific coast of Baja California and have been reported from as far north as southern California. However, observations of development and DNA data are necessary before their identity can be verified.

Description: shell morphology and anatomy are the same as for B. aculeatus , although the shells of the live-collected material were all smaller than large examples of B. aculeatus and B. odites . The protoconch distinguishes this species from B. calyptraeformis and B. odites , and B. pritzkeri , but cannot be used to clearly distinguish it from the other species of Bostrycapulus . B. latebrus has direct development from eggs with a diameter of 488 Mm. The embryos develop into intracapsular ‘veligers’ with a very small but distinct un-pigmented velum, a small round head vesicle and a single embryonic kidney on each side. An operculum is present but is lost before hatching. Embryonic shell sculpture consists of widely spaced rows of fine granules similar to the larval sculpture of C. lingulata ( Collin, 2000b) . Embryos hatch as crawling juveniles. Maximum shell length 16 mm (N = 20).

Etymology: The species name latebrus is Latin, meaning ‘hidden’ or ‘obscure’, referring to both the difficulty of distinguishing this from the other species of Bostrycapulus and also to the fact that shells are often so encrusted with epibionts that they are effectively hidden in the field.

Notes: C. californica Tryon, 1886 is a nomen nudum. However, it may possibly have been applied to this species in the previous literature. Fossil shells with similar morphology occur in the Pliocene and Pleistocene of California, USA and Baja California, Mexico.

Figures

Figure 11. The shells of the holotypes of the four new species. A, Bostrycapulus latebrus (FMNH 282358). B, B. odites (Natal Museum V9447/T1783). C, B. pritzkeri (Australian Museum #C400000). D, B. urraca (ANSP 412178). Scale bar = 10 mm.