Clathrina maremeccae Van & De 2018, sp.nov.
Creators: name: Van, Rob W. M.
name: De, Nicole J.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Calcarea
Clathrinida
Clathrinidae
Clathrina
Clathrina maremeccae

description: Clathrina maremeccae sp.nov.
Figures 25a–c
Material examined. Holotype, RMNH Por. 9662, Saudi Arabia, Jeddah, near Thuwal, Um Albalam, 22.193556°N 38.9475°E, scuba, coll. N.J. de Voogd, field nr. THU10/JED166, 12 November 2014.
Description. Cormus clathroid (Fig. 25a), forming a loosely anastomosed small mass of tubuli 0.2–1 mm in diameter leading to a few wider oscules. The single specimen is 15 x 8 x 4 mm in size. No evident water-collecting tubes. Color pale yellow, based on an on deck photo as there is no in situ photo.
Skeleton. (Fig. 25b) The tubule walls have a single layer of overlapping triactines.
Spicules. (Figs 25c) Equiradiate and sagittal triactines, with cylindrical actines, ending in often slightly swollen, blunt endings. Actines 67– 127.8 –165 x 5 – 6.4 –7.5 µm. A few broken trichoxeas are considered foreign.
Distribution and ecology. Saudian part of the Red Sea, on reefs.
Etymology. The name refers to the type locality, the Red Sea, which was named Mare Mecca by historical geographers (Wikipedia.org).
Remarks. The new species resembles Red Sea Clathrina rotundata Voigt et al., 2017 both in morphological aspects (loosely clathroid and with cylindrical actines of the triactines), and in a molecular sense as this species, based on partial 28SrRNA, also falls outside the larger clades of Clathrina species in our phylogenetic tree of Western Indian Ocean Clathrina species (Fig. 2A). However, there are also compelling reasons not to assign the present specimen to C. rotundata. Morphologically, the on deck photo shows a pale yellow color, whereas C. rotundata is white, and the upper actine length of the triactines is considerably higher than that of C. rotundata (165 vs. 123 µm). Molecularly, according to our phylogenetic analysis, the two species are not closely related. In a separate trimmed alignment of the two species of 382 sites length, C. maremeccae sp.nov. and C. rotundata differed in 49 sites.
There is considerable morphological similarity with Indonesian Clathrina beckingae Van Soest & De Voogd, 2015, which has the same shape and tube diameter, colors also white and cream in various specimens, and equiradiate triactines with cylindrical actines. Differences are the presence of distinct water-collecting tubes and the absence of sagittal spicules in C. beckingae. Actine sizes of the triactines are also considerably smaller than those in C. maremeccae sp.nov. (up to 103 µm in C. beckingae). We obtained partial 28srRNA sequences for this Indonesian material, and found that it differed in a separate trimmed 28S rRNA alignment of 382 sites length in 26 different sites.
No closely related species were identified in our partial 28SrRNA tree (Fig. 2A).
At the suggestion of one of the reviewers, we obtained an ITS sequence (not submitted to GenBank) for this species and in an analysis (not shown here) of ITS sequences of Clathrina species that appeared highly similar in a BLAST attempt, downloaded from GenBank, we noted that the new species ended up in a highly supported clade with Clathrin a sp. 4 and sp. 5 sensu Klautau et al. 2013, respectively a species from the Caribbean and from French Polynesia. A trimmed alignment of 556 sites of the three species showed 35 site differences between C. maremeccae sp.nov. and C. sp. 4, and 21 site differences with C. sp. 5.
description: Published as part of Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, pp. 1-160 in Zootaxa 4426 (1) on pages 50-52, DOI: 10.11646/zootaxa.4426.1.1, http://zenodo.org/record/1271239