Anachis pardalis ( Hinds, 1843 )

Maintenon, Marta J., 2014, Taxonomic revision of the species of Parvanachis Radwin, 1968 (Gastropoda: Columbellidae) from the Gulf of Panama, Zootaxa 3753 (3), pp. 201-225 : 221-223

Anachis pardalis ( Hinds, 1843)

Figure 9 A–G

Clavatula pardalis Hinds, 1843 : p. 42, not figured. 1844: p. 22, pl. 7, fig. 1.

Pleurotoma pardalis ( Hinds, 1844) . Reeve, 1843 (Oct. 1845): pl. 23, sp. 196.

Columbella sulcosa Sowerby, 1844 (not Sowerby, 1832?): pp. 141-142, pl. 40, fig. 165. Mangelia sulcosa ?. C.B. Adams, 1852: pp. 373–374, not figured.

Columbella (Seminella) sulcosa Sowerby. Kobelt, 1897 : pp. 200 - 201, taf. 27, fig. 18. Anachis carmen Pilsbry & Lowe, 1932 : p. 71, pl. 5 fig. 4. Keen, 1958: p. 380, sp. 423 (illustration from Pilsbry & Lowe). Anachis pardalis ( Hinds, 1844) . Keen, 1958: p. 383, sp. 446 (illustration from Hinds, 1844 –1845. Anachis (Parvanachis) pardalis ( Hinds, 1843) . Keen, 1971: 585, sp. 1208.

Parvanachis pardalis ( Hinds, 1843) . Skoglund, 1992: 89.

Types. Lectotype, NHMUK 1844.6.7.56, from the Gulf of Nicoya, Costa Rica. This was a syntype; Keen (1971) figured it and incorrectly called it the holotype, but noted that this is not the specimen illustrated by Hinds, or Reeve (1843), who essentially copied Hinds’ figure. According to Andreia Salvador at NMHUK, there is another registration number on the board with this known syntype, but no specimens have yet been found corresponding to this number, and Sowerby’s types also could not be located. Therefore this remaining syntype is herein designated as a lectotype to stabilize the identity of the species.

Taxonomic history. This species was named by Hinds as a turrid, and as Keen (1971) points out, his figure (published later) was rather poor, featuring only the dorsal side, and the species was not recognized as a columbellid for many years. Pilsbry & Lowe (1932) published Anachis carmen as a new name for Columbella sulcosa Sowerby (1844) , on the basis that the 1844 illustration and text referred to a different species than that described (but not figured) by Sowerby in 1832. Sowerby’s 1832 description suggests a much larger species, possibly from Polynesia; however sizes are not listed in his 1844 publication, and the specimen figured appears to be the much smaller Panamic species. Perhaps because of this, C.B. Adams was uncertain of the identity of his species. Pilsbry & Lowe also maintained that A. carmen was different than Hinds’ species, having a more slender shape. A. carmen has since been recognized as a synonym ( Keen 1971) of Clavatula pardalis . As discussed below, its anatomy is quite different from that of species of Parvanachis , and so should be considered as a species of Anachis until a thorough analysis of the group is carried out.

Diagnosis. Biconic, axially ridged species 7 to 9 mm long and less than half as wide, uniformly dark brown with yellowish lines atop the axial ridges, and spiral grooves between ridges.

Material. 18 specimens were collected from Playa Rio Mar in 2006, on and under high intertidal rocks. Two adult specimens were sectioned and two dissected. USNM has representatives of this species from Panama and Ecuador.

Shell ( Fig. 9 A): Shell medium-sized, biconic, 7.60 to 8.57 (avg. 8.08) mm long and 2.95 to 3.58 (avg. 3.20) mm wide in eight specimens measured. Adults have 6.25 to 7 (avg. 6.6) teleoconch whorls. Protoconch smooth, tan, with 3 whorls (in four specimens) and a moderate velar sinus. Shell dark grey or brown, nearly black, with light yellowish axial stripes on the tops of the axial ridges that are the predominant sculpture. Shell has close-set spiral grooves between axial ridges, and a weak subsutural groove. Axial ridges fade on dorsal side of body whorl. Aperture narrow and darkly pigmented, with a posterior notch in the aperture edge, labial denticles and a parietal ridge.

Body coloration. Preserved animals densely mottled with black blotches overall, sole of foot cream colored. Cephalic tentacles white with medial black bands. Siphon densely spotted with black.

Operculum ( Fig. 9 B): Operculum elongate oval, more pigmented in the middle. There is a keel and a bilobed muscle scar.

Radula ( Fig. 9 C): Radula narrow, with lateral teeth 35 to 40 µm long in two specimens dissected. Center plates are about twice as wide as deep. Each lateral tooth has three secondary cusps, with basal cusp similar to the other two, and embedded in membranes. The radula in one specimen had 125 tooth rows.

Reproductive anatomy: Gonoduct anatomy in this species not typical for Parvanachis , instead resembling species of Anachis . Convoluted seminal vesicle contains a mix of dark staining normal sperm cells and red staining atypical cells. Anterior end of seminal vesicle continues into a sac-like secondary vesicle ( Fig. 9 D). Secondary vesicle wall has low epithelium with some brown staining material present in the cells, and the vesicle is full of red-staining atypical sperm cells. Densely ciliated mantle cavity duct splits from spermiduct anterior to where it joins the secondary vesicle. Anterior body wall spermiduct narrow, densely ciliated. No free spermiduct loop present. Body wall spermiduct develops tall, eosinophilic secretory epithelium close to penis base, which continues into penis. Penial spermiduct winding ( Fig. 9 E). Penis shape simple, with a filament tip. Penis at rest stored in pouch in mantle cavity roof under the hypobranchial gland ( Fig. 9 E).

Oviduct also typical for species of Anachis ; there is a large bursa copulatrix, and a long, coiled, muscular vestibule; but no gonopericardial duct. Anterior oviduct comprises a single gland mass ( Fig. 9 F), which stains red anteriorly, with a dark purple staining band through middle toward the posterior end. Portion of gland posterior to dark band stains pale purple. Gland lumen flat and broad. Posterior end of gland mass very flat, duct lumen curves toward ventral body wall. Anterior end of gland mass has moderately long vestibule ( Fig. 9 G) with a folded, muscular wall. Appended on the dorsal side is a round bursa copulatrix ( Fig. 9 G) with pouched but not particularly secretory wall.

Remarks. This species has been placed in Parvanachis in recent years perhaps because of its small size; it does not have a globose shell form, and the radula, though similar to those of the Parvanachis species, lacks the down-hooked shape of the basal cusp of the lateral teeth. It also doesn’t closely resemble any other Panamic species. More important though, the reproductive anatomy is considerably different than that of any species of Parvanachis . Species with similar anatomy occur in both Costoanachis and Anachis , but these two genera as currently known are both anatomically and morphologically diverse. Costoanachis was unfortunately based on a Neogene fossil species ( Columbella (Anachis) turrita Sacco, 1890 , renamed by Radwin (1977b) Costoanachis saccostata ) from Europe, so cannot be anatomically characterized. Anachis is based on the large Panamic species Anachis scalarina , but the genus name is widely used for axially ribbed species. The reproductive anatomy of A. scalarina is similar to that of this species and other Anachis and Costoanachis species described by Marcus & Marcus (1962) and Houston (1976). Radwin (1977b) interprets Costoanachis as confined to species that lack axial ridges on some portion of the shell spire. Insomuch as this species has axial ridges over the entire spire, it is anatomically similar to Anachis scalarina , and considering it probably is not possible to determine exactly what Costoanachis actually is due to lack of anatomical and molecular data, this species should be referred to as Anachis pardalina until a global systematic analysis can be carried out.

Figures

FIGURE 9. Shell, anatomy and morphology of Anachis pardalis. Scale bars: A, 1 mm; B, C, 30 µm; D – G, 200 µm. A. Shell, USNM 1231330, Playa Rio Mar. B. Operculum from adult male, 48 X. C. Radula from adult male, 400 X. D. Cross section of body showing secondary seminal vesicle. E. Cross section of animal showing section of penis, housed in a cavity between the hypobranchial gland and body wall. F. Cross section of female reproductive gland mass, with anterior to the right. G. Cross section of bursa copulatrix, with part of the duct and vestibule.