Bostrycapulus odites, 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 : 96-97

BOSTRYCAPULUS ODITES SP. NOV.

Synonymy

Crepidula aculeata - Parodiz, 1939 [in part]: 695. Hoagland, 1977 [in part]: 364.

Crepidula aculeata var. fortis - Parodiz, 1939: 696.

Bostrycapulus aculeatus - Olsson & Harbison, 1953 [in part]: 280. Simone, 2002 [in part]: 18.

Crepidula cf. aculeata - sp. 1, Collin, 2003b: 618– 640.

Crepidula cf. aculeata - South Africa. Collin, 2003a: 541–593.

Crepidula cf. aculeata - Argentina. Collin, 2003a: 541–593.

Crepidula cf. aculeata - Brazil. Collin, 2003a: 541– 593.

Holotype: Natal Museum V9447 / T1783 , shell and ethanol-preserved soft parts. Shell illustrated in Figure 11 ; length 19.3 mm, width 15.6 mm, height 7.2 mm. Frozen tissue of this specimen: FMNH 282360 .

Other live-collected material from the type locality: FMNH 282277 (paratype) , BM20010453 .

Other live-collected material examined: FMNH 282297, ANSP A19744 , BM 20010456, FMNH 282350, FMNH 282368

Type locality: Wooleys Pool, Muizenburg, Cape Province, South Africa. Low intertidal zone in rock crevices, co-occurring with Crepipatella capensis .

Diagnosis: B. odites differs from the other species in the B. aculeatus species complex in exhibiting direct development from small eggs which consume nurse eggs. The protoconch is unsculptured and retains irregular growth lines ( Figs 5F , 4I ). Adult morphological characters are as described above for B. aculeatus . Diagnostic DNA sequence differences distinguishing B. odites 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 ): 24 (c), 36 (g), 141 (c), 220 (t), 234 (c), 279 (g), 354 (t), 438 (c), 486 (a), 552 (t).

Distribution and habitat: the Atlantic coast of South America, from São Paulo, Brazil to Puerto Madryn, Argentina, as well as the south coast of South Africa from Cape Town to Port Elizabeth and north to northern Natal (Natal Museum). Material examined here was collected from rocks intertidally in South Africa and Brazil, and intertidally from rocks and subtidally from the shells of pen-shells and oysters in Argentina. This species occurs to depths of at least 40 m.

Description: shell morphology and anatomy are the same as B. aculeatus , with the exception of the protoconch. The 1 mm diameter protoconch is smooth with irregular growth lines towards the aperture ( Figs 5F , 4I ). The indistinct protoconch–teleoconch boundary occurs after slightly more than a single whorl is completed.

Observations of development are available for animals from Argentina and Cape Town, but only the early stages were collected. Eggs from Argentinian animals are 197 Mm in diameter. All eggs in a capsule begin to develop synchronously and gastrulation includes invagination. Gastrulas look similar to those of C. lingulata ( Collin, 2000b) . After gastrulation, the nurse eggs remain spherical with centralized yolk and ciliated epithelium. After consuming the nurse eggs, the remaining embryos form intracapsular veligers with a single embryonic kidney on each side, a distinct operculum, a very small distinct velum with a food groove, a small round head vesicle, and some black pigment on the intestine. The shells of early embryos appear smooth under a dissecting microscope. Embryos near hatching were not observed in October and November in Argentina, or December in South Africa. I observed the development of a few broods of South African animals. It appears that the embryos begin to consume the nurse eggs slightly earlier in development than those from Argentina, and that the larval features are therefore slightly less well developed relative to embryo size. Maximum length = 30 mm.

Etymology: odites is a Greek noun meaning traveller. This name refers to the large geographical distribution this species has attained despite its direct development.

Figures

Figure 4. Unrooted haplotype network of COI sequences from Bostrycapulus calyptraeformis. Slashes on branches show the number of differences between the haplotypes. Branches without slashes have a length of one. Size of the circles represent the number of individuals with that haplotype.

Figure 5. Protoconchs. A, Bostrycapulus pritzkeri sp. nov. from Sydney. B, B. calyptraeformis from the Perlas Islands, Panama. C, B. cf. tegulicia from Cape Verde. D, B. gravispinosus from Minabe, Wakayama Prefecture, Japan. E, B. calyptraeformis from Paita, Peru. F, B. odities sp. nov. from Playa Orengo, Argentina. G, B. urraca sp. nov. from Isla Parida, Panama. H, B. aculeatus from Lido Key, Florida. I, B. odites sp. nov. from São Paulo, Brazil. All are to the same scale. Scale bar = 500 Mm.

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.