Caecum chinense Folin, 1868

Albano, Paolo G. & Pizzini, Mauro, 2011, Notes on Caecidae (Mollusca: Gastropoda) from southern Mozambique, with the description of a new species, African Invertebrates 52 (1), pp. 1-1 : 3-5

Caecum chinense Folin, 1868

Figs 2A–H

Caecum chinense: Folin 1868: 80 .

Original description:

“ Testa conica, parva, angustissima, sat elongata, subopaca, albida, levi, transversim aliquibus strigis minutissimis irregulariter cingulata, aperturam versus fere LQÀDWD; apertura levitissime contracta, vix declivi, haud marginata: septo magno, conico, apice subacuto, margine laterali et dorsali VXEUHFWLV; operculo?

Long.: 0,001 3; diam.: 0,000 2 - 0,000 25 ”

Redescription:

Shell slender, subcylindrical, slightly arched, opaque white. Juvenile specimens have more slender shell, which looks sinusoidal when seen ventrally ( Figs 2D, 2E ). Tube VHHPV VPRRWK EXW KDV PLFURVFXOSWXUH RI YHU\ ¿QH JURZWK OLQHV ()LJ. ƻ&). $SHUWXUH FLUFXODU DQG VOLJKWO\ FRQWUDFWHG. 6HSWXP SUR¿OH SRLQWHG DQG VKDUS LQ IUHVK VSHFLPHQV but tends to become blunt in older or worn specimens. Its dorsal and ventral margins almost straight. Operculum ( Figs 2F–H ) 0.3 mm in diameter, corneous and light brown. Its outer surface crossed by 3–4 small, concentric, indistinct rings, going from edge to- ZDUG URXQG, VOLJKWO\ FRQFDYH QXFOHXV ZLWK ³±4 ¿QH FRQFHQWULF ULQJV.,WV PDUJLQDO DUHDV have more marked concentric ridges and margin much thicker than rest of operculum. Its inner surface crossed by 3–4 small, concentric, rough and indistinct rings.

Soft parts unknown.

Mean dimensions: length 2.9 mm, min. diameter 0.3 mm, max. diameter 0.5 mm.

Type material (examined): 4 syntypes at MNHN ( Kisch 1959).

Type locality: Near Deux Freres , South China Sea .

Material examined: Loc. 2035: 2 spec. and 59 sh. (8 juv.); Loc. 2036: 2 spec. and 43 sh. (4 juv.); Loc. 2037: 6 spec. and 1 sh.; Loc. 2847: 1 spec. + 33 sh. (2 juv.) (P.G. Albano coll.).

Additional material examined: SOUTH AFRICA: KwaZulu-Natal: 1 sh., Stn SO 4, off Cape St Lucia (28°31.8'S: 32°26.9'E), - 76–80 m, dredged R.V. NMDP, 12.vi.1988 ( NMSA E5196 ) ; 1 sh., Leadsman Shoal, Raggie Reef, - 8–14 m, a mixed algal and coral reef, 1–2 km north of Leven Point , sorted from stone washings ( NMSA E2726 ) ; 5 sh., Mapelane ( NMSA E1662 ) ; 6 sh., Mission Rocks , N of St Lucia (J.P. Marais coll.) ; 13 sh., Mapelane, S of St Lucia (J.P. Marais coll. 2116); 86 sh., off St Lucia Lighthouse, - 50 m, ex CSIR Water Research ( NMSA A6212 ) ; 1 sh., Richards Bay , sand from harbour dredger ( NMSA E1667 ) ; 1 sh., RII 5LFKDUGV %D\, VKDOORZ GUHGJLQJV (-.3. 0DUDLV FROO. ƻƗƗ9); 7 VK., RII 5LFKDUGV %D\, ‒ƽƟ P, ¿QH TXDUW]LWH, broken shell, ex CSIR Water Research ( NMSA A6071 ) ; 1 spec. + 9 sh., Durban Bay, shallow dredgings (J.P. Marais coll. 2118); 84 sh., Durban Bay , shallow dredgings, sand ( NMSA A5423 ) ; 79 sh. + 2 fragments, Durban Bay , shallow dredgings ( NMSA E1019 ) ; 2 sh., Aliwal Shoal, off Scottburgh , - 10 m, sand and reef debris ( NMSA S8217 ) ; 1 sh., Aliwal Shoal, off Scottburgh , - 16 m, hand dredged sand ( NMSA S5922 ) ; 2 spec. + 1 sh., Aliwal Shoal (off Umkomaas ), - 27 m, silt from between rocks ( NMSA E1669 ) ; 1 sh., Aliwal Shoal , - 9–15 m ( NMSA E6166 ) ; 2 sh. (worn), Aliwal Shoal, off Scottburgh , - 10–20 m, sand ( NMSA S6743 ) ; 2 spec., Aliwal Shoal, off Scottburgh , c. - 20 m, hand-dredged sand ( NMSA S7902 ) ; 1 spec., Aliwal Shoal, off Scottburgh , c. - 14 m ( NMSA S6160 ) ; 14 sh., Aliwal Shoal, off Umkomaas , - 27 m, scuba, January 1988 (J.P. Marais coll.) ; 1 sh., South Coast, Landers Reef, off Scottburgh area , - 45 m, scuba, April 1988 (J.P. Marais coll.) ; 4 sh., Landers Reef off Park Rynie , - 30 m, slightly muddy sand ( NMSA E1668 ) ; 2 sh., T.O. Strand , 2 km N of Port Edward ( NMSA E1661 ) ; 5 sh. subadult, South Coast, Leisure Bay, Port Edward , beach ( NMSA 2411 ) . Eastern Cape: 1 sh., Mzamba , beachdrift ( NMSA D3032 ) ; 5 sh., Mzamba ( NMSA E1663 ) ; 23 sh., Mzamba, near KwaZulu-Natal border (J.P. Marais coll.). Western Cape: 1 sh., Hermanus (between False Bay and Cape Agulhas) (J.P. Marais coll.) .

Comparative material examined: C. attenuatum )ROLQ, Ɨ879, ¿YH V\QW\SHV DW %01+ QRV ƻ³Ɨƽ±ƻ³Ɨ9. 7\SH locality: Flinders Passage, Cape York, 7 fms, Australia ( Fig. 2K ).

Distribution: This species was described from the South China Sea. It was then recorded from North Australia (Folin 1879) and Borneo ( Kisch 1959). It is here recorded from Mozambique but it is also present in South Africa.

5HPDUNV: 6SHFLPHQV IURP 6RXWK $IULFD GR QRW VKRZ VLJQL¿FDQW GLIIHUHQFHV WR RXU PD‒ terial. C. chinense resembles C. attenuatum Folin, 1879 ( Fig. 2K ) in its general sub- F\OLQGULFDO VKDSH, EXW GLIIHUV E\ LWV VPRRWK WXEH ZKLFK LV FURVVHG RQO\ E\ ¿QH JURZWK lines, while attenuatum has a sculpture of small rings. The septum is similar in both species; in chinense , however, the mucro’s cusp is almost always pointed and a slight hump is present on the posterior margin.

Figures

Fig. 2. Caecum chinense)ROLQ, Ɨ868: ($±&) DGXOW,,QKDFD,. (/RF. ƻƟ³6): ($) VKHOO, VFDOH EDU ƽƟƟ ȝP; (%) VHSWXP, VFDOH EDU ƗƟƟ ȝP; (&) PLFURVFXOSWXUH (YHQWUDO VLGH, QHDU WKH VHSWXP), VFDOH EDU ƽƟ ȝP; (', () MXYHQLOH, %D\ RI 0DSXWR (/RF. ƻ847), VFDOH EDU ƽƟƟ ȝP: (') ODWHUDO YLHZ; (() YHQWUDO YLHZ; ()±+) RSHUFXOXP (/RF. ƻƟ³6), VFDOH EDU ƗƟƟ ȝP: ()) LQVLGH, (*) RXWVLGH, (+) SUR¿OH; (J) Caecum chinense)ROLQ,Ɨ868, V\QW\SH DW 01+1, VFDOH EDUƽƟƟ ȝP; (,,.) Caecum attenuatum)ROLQ, Ɨ879, V\QW\SH DW %01+: (,) VHSWXP, VFDOH EDU ƽƟ ȝP; (.) VKHOO, VFDOH EDU ƻƻƻ ȝP.