Aulocyathus sp.cf. matricidus (Kent, 1871)

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

Aulocyathus sp.cf. matricidus (Kent, 1871)

Fig. 1I, J

Flabellum matricidum Kent, 1871: 276, pl. 23: fig. 2A-C.

Fragilocyathus conotrochoides Yabe & Eguchi, 1932a: 388, 389, fig. 1. -Yabe and Eguchi 1941 a: 101. - Yabe and Eguchi 1942b: 116, 145. pl. 9: fig. 15. - Eguchi 1965a: 288, 4 figs. - Eguchi and Miyawaki 1975: 57.

Aulocyathus cf. matricidus . - Yabe and Eguchi 1942b: 112, 116.

Aulocyathus matricidus . - Cairns 1999a: 104. -Cairns 1994: 60, pl. 26, figs C-G, pl. 42, figs B-D.

Type locality.

Off Japan, 84 m ( Zibrowius 1980; Cairns 1994).

Type material.

Two syntypes are deposited at the NHM (Cairns 1994).

Material examined.

ORI_DIa1 (2 specimens): no locality data.

Description.

Corallum solitary, attached, and conical to elongate. Calice circular, calicular margin smooth. Largest of two specimens examined (ORI_DIa1) 5.2 × 5.1 mm in CD, and ≤ 15.4 mm in H. Costae wide. Theca and costae granular. Corallum light brown.

Septa hexamerally arranged in four cycles, the last cycle being incomplete, according to the formula: S1 > S2 > S3 > S4 (32 septa). S1-2 most exsert septa. S1 extend almost towards centre of fossa, with vertical to slightly sinuous axial margin. S2 ¼ less wide than S1, also has vertical axial margin, and being granular deeper in fossa. S3-4 progressively less exsert (if at all). S3 dimorphic in size: those half-systems lacking S4 only ½ the width of S2, while those flanked by S4 attain almost the same width of S2. If present, S4 ½ the width of S3. Axial margins of S3-4 dentate. Septal faces finely granular. Fossa deep containing a rudimentary columella.

Distribution.

Regional: Eastern margin of South Africa; depth unknown. Elsewhere: Tsugara Strait; and Japan Sea (Cairns 1994); 84-207 m.

Remarks.

Among all congeners, specimens examined closely resemble Aulocyathus matricidus in having a smooth calicular margin, upper peripheral septa not notched, rudimentary columella, and a slender pedicel. However, A. matricidus is only known from Japan and, therefore, its occurrence in the southwestern Indian Ocean would represent a disjunct distribution.

Figures

Figure 1. A, B Anomocora fecunda (SAMC _ A 073042, off Shaka's Rock, 200 m) A calicular view B lateral view C, F Anomocora marchadi C, D (SAMC _ A 090093, off Durban, 49 m) C calicular view D lateral view E, F (SAM _ H 3100, off Shaka's Rock, 66 m) E calicular view F lateral view G, H Aulocyathus juvenescens (Mortensen 25, off Durban, 424 m) G calicular view H lateral view I, J Aulocyathus sp. cf. Aulocyathus matricidus (DIa 1, locality data unknown) I calicular view J lateral view K, L Caryophyllia (Acanthocyathus) grayi (USNM 91541, off Kosi Bay, 98 m) K calicular view L lateral view M, N Caryophyllia (Caryophyllia) diomedeae (MN _ SM 129, off Margate, 850 m) M calicular view N lateral view N, O Caryophyllia (Caryophyllia) ephyala (SAMC _ A 072974, off Paternoster, 440 m) O Calicular view P Lateral view. Scale bars: 10 mm.