Clathrina laminoclathrata, CARTER, 1886

Klautau, Michelle & Valentine, Clare, 2003, Revision of the genus Clathrina (Porifera, Calcarea), Zoological Journal of the Linnean Society 139 (1), pp. 1-62 : 29-30

CLATHRINA LAMINOCLATHRATA CARTER, 1886

Type locality: Port Phillip Heads , VIC. ( Australia) .

Type: BMNH 1887.7 .12.42 (lectotype /dry). There is a label on which is written: Grantia laminoreticulata n.sp. Ott n∞18 (12.2.86) .

BMNH 1887.7 .12.43 (syntype /dry) .

Both from Port Phillip Heads, VIC. ( Australia), J. Bracebridge Wilson Collection.

Citations: Dendy (1891); Dendy & Row (1913); Burton (1963).

Colour: There are two dried sponges attached to a stone. One of them is light yellow and has a continuous and hispid surface, with large external spicules. The specimen in question is on the other side of the stone. It is light grey and is formed by regular and tightly anastomosed tubes ( Fig. 22A ).

Description: This specimen is a little different from the other Clathrina species examined. Under the tubes, directly in contact with the substrate, there is a continuous membrane, a basal lamina, and above it the anastomosed tubes characteristic of Clathrina . It is possible that this basal lamina is only an artefact created by the dried state of the specimen as Dendy (1891) supposed, but the skeleton in this region of the sponge is different from the skeleton in the tubes.

The skeleton is formed by triactines only ( Fig. 22B ), as stated by Carter (1886) in the original description, although there are in fact three different categories of triactines, based on size. All have conical actines and sharp tips. The largest are generally found on the external tubes of the sponge, i.e. on the surface of the cormus. They can also be found in the basal lamina, although this is rare. The other two sizes of triactines are more abundant in the basal lamina, and can also be seen on the surface of the tubes, but are less abundant.

There is no specialization of the tubes and the organization of the cormus is typical of Clathrina .

Remarks: In 1886, Carter described this species from Port Phillip Heads from a dried specimen. He described the cormus as sub-circular, steel-grey, clathrous, reticulated at the surface and with a basal lamina, and the skeleton as formed of equiangular and equiradiate triactines which vary in size.

Dendy (1891) suggested that Carter could have been mistaken when he described the basal lamina, adding that as he had examined a small, dried specimen, the lamina was probably the result of collapsed tubes. He concluded that the species should be abandoned. He later ( Dendy & Row,1913) put it on his Leucosolenia list, but as a species of doubtful value, and supported this opinion with the observation that this species was ‘too imperfectly described to be recognisable’.

We examined two specimens deposited at BMNH. Both are very similar and were collected on the South Coast of Australia, one of them from the type locality. J. Bracebridge Wilson collected them and were both dried. One ( BMNH 1887.7.12.42) is labelled as a lectotype, and the other ( BMNH 1887.7.12.43) as a syntype (cotype). They match the description given by Carter (1886) perfectly, although this description is really very incomplete. We believe that C. laminoclathrata is a valid species. Even if we consider that the basal lamina is an artefact of desiccation, there are three different categories of triactines in these specimens, which justifies the specific level. Furthermore, the distribution of these categories is different in the distinct body parts of this species, while the ‘basal lamina’ has a specific skeleton, which suggests that it is a genuine structure. As there is no well-preserved specimen, we decided to redescribe the species, based principally on the three different categories of triactines and their distribution, and consider the presence of a basal lamina only as a possibility .

Figures

Figure 22. Clathrina laminoclathrata. A, photograph of the lectotype (¥ 10). B, the three categories of triactine. Scale bar = 100 Mm.