Crispatotrochus cornu (Moseley, 1881)

Filander, Zoleka N., Kitahara, Marcelo V., Cairns, Stephen D., Sink, Kerry J. & Lombard, Amanda T., 2021, Azooxanthellate Scleractinia (Cnidaria, Anthozoa) from South Africa, ZooKeys 1066, pp. 1-198 : 1

Crispatotrochus cornu (Moseley, 1881)

Fig. 3E, F

Cyathoceras cornu Moseley, 1881: 156-157, pl. 4, fig. 7 (in part). - Cairns 1979: 67, pl. 12, figs 1, 3.

Crispatotrochus cornu . - Cairns 1991: 15. - Kitahara and Cairns 2008: 63. - Cairns and Polonio 2013: 70-71, figs 2L-M, 3A-B, 10.

Type locality.

Off Rio de la Plata, Uruguay (HMS ‘Challenger’ stn. 320: 37°17'00"S, 53°52'00"W); 1097 m ( Moseley 1881).

Type material.

Lectotype and paralectotype are deposited at the NMNH ( Cairns 1979).

Material examined.

None.

Imagery data.

UCTES_NAD 17 F (1 specimen): Eastern margin, off Isipingo; 49 m.

Description.

Corallum ceratoid, attached through a robust pedicel (PD:GCD = 0.4) that expands into an encrusting base. Calice elliptical (GCD:LCD = 1.2) with a serrated calicular margin. Only imaged specimen examined (NAD 17 1F) 5.9 × 5.0 mm in CD, 2.2 mm in PD, and 7.0 mm in H. Theca granulated. Costae prominent at calicular margin, with C1--2 more prominent and distinctive. No intercostal striae. Corallum white.

Septa hexamerally arranged in four complete cycles according to the formula: S1-2> S3> S4 (48 septa). S1-2 equal in size and exsertness, with slightly sinuous axial margins, and almost meet columella. Remaining septa (S3-4) becoming progressively less exsert. S3 ~ ¾ the width of S1-2, and have the most sinuous axial margins. S4 rudimentary, also with straight to slightly sinuous axial margins. Septal faces bear small and blunt granules. Fossa moderately deep, with a rudimentary fascicular columella composed of two twisted elements.

Distribution.

Regional: Eastern margin of South Africa, off Isipingo; 49 m. Elsewhere: Seamount or ridge on Heezen fracture zone, South Pacific; 549 m ( Cairns 1982).

Remarks.

The imaged specimen, that forms the basis of this species report, is consistent with the known description of Crispatotrochus cornu in having a robust pedicel and septa hexamerally arranged in four complete cycles (S1-2> S3> S4), but differs in having an exceptionally sinuous as opposed to a straight S3 as previously reported ( Cairns 1979, Kitahara and Cairns 2008). This species groups with the other Crispatotrochus that have septa hexamerally arranged in four cycles ( C. inornatus , C. galapagensis Cairns, 1991, C. rugosus Cairns, 1995, and C. irregularis Cairns, 1982), all previously reported from the Pacific Ocean. Crispatotrochus cornu appears to be a juvenile form and is similar to the specimens collected by RV Gerda and RV Pillsbury stations which display a pedicel measuring ½ of the calicular diameter ( Cairns 1979). However, Cairns (1979) highlights that these specimens were omitted from the description/account on the bases of immaturity and their small size. Species may have septa arranged in a decameral or hexameral fashion ( Cairns 1979, 1991), the latter being the pattern observed in the imaged specimen reported herein (UCTES_NAD17F). Nonetheless, the South African record (UCTES_NAD17F) was collected at a much shallower depth than the previously known. Despite this, specimen is added to the account and represents a new record for the Crispatotrochus in the southwest Indian Ocean.

Figures

Figure 3. A, B Caryophyllia (Caryophyllia) stellula (SAM _ H 1485, off Agulhas, 200 m) A calicular view B lateral view C, D Caryophyllia (Caryophyllia) valdiviae (SAM _ H 3108, off Durban, depth unknown) C calicular view D lateral view E, F Crispatotrochus cornu (UCT _ NAD 17 F, off Isipingo, 49 m) E calicular view F lateral view G, J Desmophyllum dianthus G, H (SAMC _ A 077974, off Paternoster, 440 m) G calicular view H lateral view I, J (BMNH. 1939.7.20.218, locality data unknown) I calicular view J lateral view K, L Desmophyllum pertusum (SAM _ H 1605, off Melkbosstrand, depth unknown) K calicular view L lateral view M, N Goniocorella dumosa (SAM _ H 3190, off Kidds Beach, 760 m) M calicular view N lateral view O, P Heterocyathus aequicostatus (SAMC _ A 073186, off Durban, 150 m) O calicular view P lateral view Scale bars: 10 mm (A-I, K-P); 100 mm (J).