Cribrarula gravida Moretzsohn, 2002

Moretzsohn, Fabio, 2002, A new species of Cribrarula (Gastropoda: Cypraeidae) from New South Wales, Australia, Zootaxa 85 (1), pp. 1-16 : 2-7

Cribrarula gravida Moretzsohn new species

( Figs. 1­6 , 22 )

Type material: Holotype ( Figs. 1­6 , 22 ) deposited in the Australian Museum, Sydney, AMS C. 91000 (length 35.15 mm, width 22.10 mm, height 18.25 mm, 20 columellar and 21 labral teeth, umbilicus (spire region) diameter 6.20 mm; see Table 1 for additional measurements and comparison with other material). The radula of the holotype was prepared and mounted on two SEM stubs and deposited at the AMS ( AMS C. 91000). Two samples of genomic DNA obtained from the holotype’s dried tissue were deposited in the tissue collection of the Australian Museum's Evolutionary Biology Unit (EBU # 11517 and 11518). Additionally, a cast of the holotype shell made from a protective coat of clear nail polish ( Fig. 28 ) (used to protect the shell during tissue digestion with a protease) was also deposited with the holotype ( AMS C. 91000).

Type locality: Fish Rock , south side, 2 km SE of Smoky Cape, New South Wales, Australia, 30 56.4’S, 153 5.9’E ( Fig. 27 ), collected at 18 m depth outside a cave .

Diagnosis: Large inflated pyriform shell, rostrate extremities, with large elliptical dorsal spots, no marginal spots, columellar teeth thicker than in other congeneric species, flared dorsal anterior extremity.

Description

Shell ( Figs.1­6 ): The shell of the holotype is large for the genus (35.15 mm in length), pyriform in dorsal profile, with produced extremities ( Fig. 1 ) and thick marginal calluses. The base and labrum are convex ( Figs. 4­6 ), and the shell is considerably inflated dorsoventrally (shell width/length ratio is 62.9%, and height/width ratio 82.6%). The aperture is slightly constricted at the center (minimum width is 2.10 mm, maximum width 2.70 mm), and curved to the left. Labral teeth (21) are thick, extending about 64% of the labrum width ( Fig. 3 ). Columellar teeth (20) are thicker than those on shells of most congeneric species, not extending far onto the base, but reaching deeply into the aperture, and forming distinctly ribbed fossula and peristome. Both the fossula and peristome are sloped, concave, and wide. The terminal ridge is long, thick, and nearly parallel to the labrum’s anterior extremity. The gap between the terminal ridge and anterior columellar teeth is similar in width to neighboring intertooth spaces. The base, labral and columellar margins and extremities are white. The white marginal calluses obliterate the dorsal pattern up to about half of the shell height on each side ( Figs. 2, 4 ). There are no marginal spots ( Figs 2, 4 ) (common on the shells of most species of Cribrarula , but rare in shells of C. cribraria ). The labrum is thick, keeled and forming a marginal sulcus near the extremities ( Fig. 1 ). The anterior region of the labrum is declivous towards the aperture ( Fig. 6 ), and the labral margin is upturned at the center ( Figs. 5, 6 ). Both the labral and columellar marginal calluses are irregular, forming slightly crenulated margins ( Fig. 3 ). The dorsum is distinctly convex, its highest point about 23.4 mm from the anterior extremity (67% of the shell length). The dorsum is light brown, densely peppered with 88 off­white elliptical spots of variable size (ranging in maximum diameter from 2.80 to 3.50 mm) ( Fig. 1 ). The dorsal spots are not very distinct, and there are no darker rings around the dorsal spots. The dorsal line is not well defined, but there are patches with overlaid “double exposure” (sensu Savazzi, 1998) pigmented layers along a region corresponding to the dorsal line ( Figs 1, 2 ). There are also smaller patches of overlaid pigmented layers on other parts of the dorsum. The dorsal line region forms an angle of about 40º with the base of the shell (dorsal line angle) when seen from the anterior canal ( Fig. 6 ). The dorsal coat produced by both lobes of the mantle is similar in color, but the dorsal spots produced by the right mantle lobe are slightly smaller than those produced by the left lobe ( Fig. 2 vs. Fig. 1 ). The umbilicus (spire region) is wide (c. 6.2 mm in diameter) and slightly umbilicated ( Fig. 5 ). The extremities are rostrated, and both anterior and posterior canals have thick margins ( Figs. 5, 6 ). The dorsal part of the anterior canal is flared up ( Figs. 2, 4 ).

Animal: The animal was dried inside the shell, with part of the mantle showing inside the aperture, the mantle bore apparently simple papillae: short, finger­like in the dry state, similar to those of other species of Cribrarula .

Radula ( Fig. 22 ): The radula of C. gravida sp. nov. is a typical radula of Cribrarula (the ‘Cicercula’ pattern of Bradner and Kay, 1996:125­147). The central tooth has two rounded basal denticles (left arrow in Fig. 22 ). The outer marginal teeth have a small projection (right arrow in Fig. 22 ) near the outer margin that was not seen in radulae of other species of Cribrarula . The average size of the central tooth of C. gravida sp. nov. was 108.4 x 93.55 m (n= 18), and central tooth L/W ratio was 1.19 (n= 14) in C. gravida sp. nov. The radular ribbon had an average width of 595 m, with an average 11.4 rows of teeth per mm of radula (n=4).

Odontophore cartilage: The pair of odontophore cartilages conforms to that of congeneric species: falciform elongated, with a spongy texture, and cream in color, except that it is larger, about double of the size of the odontophores of other species in Cribrarula (estimated at about four mm long).

Schilders’ formula: 35.63.19.18. The figures represent the following values for the holotype of C. gravida sp. nov.: 1) shell length in mm (rounded up or down to closest integer); 2) shell width­length ratio as percent; 3) number of labral teeth; and 4) number of columellar teeth (both tooth counts are “reduced” ( Schilder and Schilder 1938 ­1939: 123­ 124), representing the equivalent number of teeth in a hypothetical shell of 25 mm in length. The transformation is the following:

Number of reduced teeth = 7 + (absolute tooth count – 7) (25/shell length)

New formula: 35.2/ 62.9/ 6.2/ 2.0/ 0. The figures represent the following values for the holotype of C. gravida sp. nov.: 1) shell length in mm; 2) shell width­length ratio as percent; 3) umbilicus (spire region) diameter in mm; 4) relative columella teeth thickness; and 5) labral spot size (Moretzsohn, in prep. E).

Etymology: The epithet gravida is a noun in apposition, derived from the Portuguese, meaning pregnant, alluding to the inflated shell of the holotype. I dedicate this species to my wife, Heather, who was pregnant with our daughter Olivia when I first became convinced that this was an undescribed species.

Figures

FIGURE 27. Map of Eastern Australia showing the type locality of Cribrarula gravida sp. nov., Smoky Cape, NSW, 030°56.4'S, 153°5.9'E (N), as well as locality records of C. cribraria cribraria and C. cribraria melwardi (x) used in the multivariate analysis (Fig. 26) of shell characters to compare with the new species.

Figure 28. Holotype of C. gravida sp. nov. and its cast made of clear nail polish, used to protect the glossy exterior surface of the shell against the slightly etching buffer used during in situ digestion of the dried tissue in the shell (Moretzsohn and de Couet, in prep.). After the digestion is complete, the polish coat is peeled away, and if done carefully, a perfect cast of the shell can be obtained. Note that the polish removed the China ink used to write the catalog number on the shell labrum. The cast was also returned to the Australian Museum, and now is part of the lot AMS C. 91000.

FIGURES 1-21. 1-6) Holotype of Cribrarula gravida sp. nov. from NSW, Australia (AMS C. 91000); 1) dorsal view, with posterior extremity up; 2) labral side view; 3) ventral view; 4) columellar side view; 5) view of the anterior extremity, and 6) view of the posterior extremity; 7) pigmented shell of C. cribraria melwardi from Queensland, Australia (AMS C. 363556); 8-13) holotype of C. cribraria melwardi, from Queensland (AMS C. 57743); 14) large shell of C. cribraria (usually identified as zadela”) from Cebu, Philippines (USNM 773378); 15-20) typical shell of C. cribraria cribraria from Queensland (AMS C. 81677); and 21) inflated shell of C. gaskoini from Hawaii (CMB 8-37). Scale bar is 10 mm. Arrows in the figures (13, 16-20) show the following characters: CMC= columellar marginal callus; CT= columellar teeth; DL= dorsal line; DLA= dorsal line angle; FS= fossula; MSu= marginal sulcus; and TR= terminal ridge.

FIGURES 22­25. Scanning electron micrographs of radulae: 22) Cribrarula gravida sp. nov., holotype (AMS C. 91000), New South Wales, Australia ­ arrows point to two differences from other radulae shown here (see discussion); 23) C. cribraria melwardi (DMNH 31496), Swinger Reef, Queensland, Australia; 24) C. cribraria cribraria (USNM 773496), Mamanuca Group, Fiji; and 25) C. cribraria cribraria (melanic) (ANSP 271247), Baie Ouemo, New Caledonia.