Cerithidea dohrni ( Kobelt, 1890 )

Reid, David G., 2014, The genus Cerithidea Swainson, 1840 (Gastropoda: Potamididae) in the Indo-West Pacific region, Zootaxa 3775 (1), pp. 1-65 : 39-41

Cerithidea dohrni ( Kobelt, 1890)

( Figures 11 , 12 A, Q–CC)

Cerithium obtusum — Quoy & Gaimard, 1834: 126 –127, Atlas Mollusques pl. 55, figs 18–21 (shell, headfoot, operculum) (not Lamarck, 1822).

Cerithium (Cerithidea) kieneri var. dohrni Kobelt, 1890a: 49 –50, pl. 10, figs 4, 5

( Philippines; lectotype here designated SMF 228131, Fig. 12 Y, Z; 2 paratypes SMF 228132/2 ;

Cecalupo 2005: pl. 31, fig. 4).

Cerithidea dohrni — Reid et al., 2013: figs 1 (phylogeny), 2 (map).

Cerithidea quadrata — Hidalgo, 1904 –1905: 203 (not Sowerby, 1866). Dautzenberg & Fischer, 1906: 410–411 (in part, includes C. quoyii ; not Sowerby, 1866). Lozouet, 2008: 286, pl. 88, fig. 5a, b. (not Sowerby, 1866). Lozouet & Plaziat, 2008: 57, 112, fig. 30, pl. 20, figs 1–3 (not Sowerby, 1866).

Cerithidea reidi — Cecalupo, 2005: 316, pl. 31, fig. 4 (not Houbrick, 1986). Cecalupo, 2006: 60, 197, 233 (in part, includes C. reidi , C. anticipata ; not Houbrick, 1986).

Taxonomic history. This species was introduced as a variety of C. kieneri (= anticipata ) by Kobelt (1890a) and has generally been identified as C. quadrata (= quoyii ) since then. It was recognized as distinct by Reid et al. (2013) as a result of molecular analysis. A photograph of only one of the three syntypes in SMF has been seen; this had been marked as ‘lectotype’ by Zilch, but this designation remained unpublished (R. Janssen, pers. comm.) and is confirmed here in order to fix the identity of the taxon.

The identity of C. similis Adams, 1855 , likewise described from the Philippines, is unknown (see Excluded and Doubtful Species, above).

Diagnosis. Shell: spire straight to slightly convex, whorls rounded, periphery angled; aperture flared, anterior canal and apertural projection well developed; 17–35 axial ribs on penultimate whorl, 4–7 after ventrolateral varix; ventrolateral varix an enlarged rib at 190–240°; 7 spiral cords on spire, 6 cords above periphery on last whorl, giving fine reticulate sculpture; brown with darker spiral cords. Philippines, Sulawesi, Moluccas. COI GenBank AM932769 –932770, HE680229 , HE680232 .

Material examined. 27 lots.

Shell ( Fig. 12 Q–CC): H = 21.3–43.3 mm. Shape elongated conical (H/B = 2.34–2.50, SH = 3.05–3.45); decollate, 7–9 whorls remaining; spire whorls rounded, suture distinct; spire profile straight to slightly convex; periphery angled; thin to moderate thickness. Adult lip flared, thickened; apertural margin planar in side view; strong anterior projection adjacent to deep notch of anterior canal. Sculpture on spire of straight to slightly curved (opisthocyrt) narrow axial ribs, interspaces 1–2 times width of ribs, 17–35 ribs on penultimate whorl, 4–9 ribs after ventrolateral varix (i.e. about twice as distant as on spire), remaining strong throughout final whorl except for weaker 1 or 2 ribs before aperture, only faint axial wrinkles on base; spire whorls with 7(8) spiral cords (posterior 2 small), forming small nodules where they cross axial ribs, spiral interspaces 1.5–2 times width of cords, no interpolated threads, 6(7) spiral cords above periphery on last whorl; overall effect is of fine reticulate sculpture; base with (7)9–16 spiral ridges, outermost is peripheral cord of same size as primary cords above. Ventrolateral varix a strongly enlarged rib at 190–240°, forming anteriorly projecting boss at periphery. Surface with fine spiral microstriae on periostracum, strongest on spiral cords. Colour: brown, spiral cords darker brown; aperture pale brown, spiral lines showing through.

Animal: Head and base of tentacles pinkish grey with cream spots; anterior half of snout blackish with scattered yellow spots; tentacles pale grey with black rings; sides of foot pale grey, blackish anteriorly, with small yellowish cream spots; sole of foot grey, pinkish towards margin; mantle pale grey with pinkish stripes at margin (corresponding to shell ribs) (based on ethanol-preserved specimens). Quoy & Gaimard (1834) described and illustrated a black snout with one pinkish and two distal transverse yellow bands, a greenish head with brown spots, reddish tentacles with brown rings, the foot yellow spotted with black and the sole violaceous and edged with yellow.

Range ( Fig. 11 ): Philippines, Sulawesi, Moluccas. Records: Philippines: Manila Bay, Luzon ( NHMUK 20130252; AM C.33600; USNM 232955); Busuanga ( USNM 233012); Abatan R., Bohol ( NHMUK 20130255; MNHN); Iwahig, Palawan ( USNM 862793); Jolo ( USNM 233115). Indonesia: S Bolo Bay, Cape Kawala, Luwuk Peninsula, Sulawesi ( ZMB 191378a); Buru, Moluccas ( Quoy & Gaimard, 1834).

Quoy & Gaimard (1834) described receiving specimens from the inhabitants of Ile Bourou (Buru, Indonesia) and illustrated the living animal, so that the provenance of this southernmost record cannot be doubted. There are no confirmed records from Borneo and, if correctly identified, the specimen from ‘Borneo’ in Figure 12 A is believed to be wrongly localized.

Habitat and ecology. In Bohol ( Philippines) Lozouet & Plaziat (2008) found it in a mixed mangrove forest at the mouth of an estuary (salinity 10–31 ppt) and also on the lower trunks of trees and on Nypa , behind the seaward edge of the forest. They noted that is was replaced by C. balteata where the salinity was below 10 ppt.

Remarks. This species was recognized as distinct from C. quoyii as a result of molecular analysis ( Reid et al. 2013; Fig. 1 ; see Remarks on C. quoyii ). The three species in the C. quoyii group are closely similar, but there are consistent differences in their shells ( Table 1 ). The present species most resembles C. quoyii and the two may prove to be sister taxa when samples of the third member become available.

A single tissue sample (no shells available) from eastern Sulawesi showed an uncorrected pairwise distance for COI of 0.075 from three samples from the Philippines, which is high for an intraspecific comparison in this genus and exceeds the minimum distance between recognized species (0.072 for C. anticipata and C. reidi ), so further investigation of genetic structure within C. dohrni is desirable. A shell from Buru, also in eastern Indonesia, was illustrated by Quoy & Gaimard (1834: fig. 18); this is narrower than most C. quoyii , has a more rounded periphery and cancellate sculpture; it therefore resembles C. dohrni from the Philippines and is identified accordingly (it could not be confused with the small, slender forms of C. anticipata found further east in New Guinea). These are the only two records of the species from eastern Indonesia. In contrast, C. balteata from the same region is relatively well represented in museum collections, so C. dohrni appears to be scarce there.

It is not collected for food in Bohol ( Lozouet & Plaziat 2008).

Figures

FIGURE 1. Molecular phylogeny of Cerithidea species produced by Bayesian analysis of partial COI sequences, using Cerithideopsilla species as outgroup (after Reid et al. 2013). Localities details given by Reid et al. (2013). Support values are posterior probabilities; only values ≥ 0.95 (i. e. with strong support) are shown.

FIGURE 11. Distribution of Cerithidea anticipata (squares), C. reidi (stars), C. quoyii (circles), C. andamanensis n. sp. (crosses) and C. dohrni (triangles). Solid symbols, specimens examined; open symbols, literature records: A, Houbrick (1986); B, Quoy & Gaimard (1834); C, Morlet (1889).

FIGURE 12. B – J, Cerithidea quoyii. K – P, C. andamanensis. A, Q – CC, C. dohrni. A, Specimen labelled as a syntype of Cerithium quoyii Hombron & Jacquinot, 1834, ‘ Borneo’ (MNHN 25693), but this is not accepted (see text). This shell is probably a specimen of C. dohrni. B, Uglam Hujung, Kudat, Sabah, Malaysia (NHMUK 20130247). C, Ban Na Glua, Chantaburi, Thailand (NHMUK 20130248). D – G, C. quadrata G. B. Sowerby II, 1866, syntype, Melaka, Malaysia (NHMUK 20130228; views of same specimen). H – J, Ubin I., Singapore (NHMUK 20130249; I, J views of same specimen). K – N, C. andamanensis n. sp., holotype, King I., Mergui Arch., Burma (NHMUK 1887.3.10.24; views of same specimen). O, juvenile, Ao Nam Bor, Phuket I., Thailand (NHMUK 20130250). P, Andaman Is (NHMUK 20130251). Q, Manila, Philippines (NHMUK 20130252). R, Iwahig, Palawan, Philippines (USNM 862793). S – V, no locality (NHMUK 20130253; views of same specimen). W, X, Cavite, Luzon, Philippines (USNM 232955). Y, Z, Cerithium (Cerithidea) kieneri var. dohrni Kobelt, 1890, lectotype, Philippines (SMF 228131). AA, Lapu Lapu, Mactan, Philippines (NHMUK 20130254). BB, Abatan R., Bohol, Philippines (NHMUK 20130255). CC, Abatan R., Bohol, Philippines (MNHN M 49 / BC 2153). Photography credits: A, MNHN; Y, Z, S. Hof, courtesy R. Janssen, SMF.