Clathrina curacaoensis, Cóndor-Luján & Louzada & Hajdu & Klautau, 2018

Cóndor-Luján, Báslavi, Louzada, Taynara, Hajdu, Eduardo & Klautau, Michelle, 2018, Morphological and molecular taxonomy of calcareous sponges (Porifera: Calcarea) from Curaçao, Caribbean Sea, Zoological Journal of the Linnean Society 183 (3), pp. 459-525 : 472-473

publication ID	https://doi.org/10.1093/zoolinnean/zlx082
persistent identifier	https://treatment.plazi.org/id/2B7987A4-FF87-FFF9-A666-F7BEFD5BFD8E
treatment provided by	Plazi
scientific name	Clathrina curacaoensis
status	sp. nov.

Treatment

CLATHRINA CURACAOENSIS View in CoL SP. NOV.

( FIG. 6 View Figure 6 ; TABLE 4)

Etymology: Named after its type locality. Type locality: Sunset Waters, Soto, Curaçao.

Material examined: Holotype. UFRJPOR 6734, Sunset Waters , Soto, Curaçao (12°16′01.58″N, 69°07′44.85″W), 3–10 m depth, coll. B. Cóndor-Luján, 20 August 2011. GoogleMaps

Diagnosis: Clathrina with cormus formed by loosely anastomosed tubes.The skeleton is composed of regular and parasagittal triactines. Parasagittal triactines are only present in the tubes used for attachment to the substrate. Yellow in life.

Colour: Yellow in life and light beige in ethanol ( Fig. 6A View Figure 6 ).

Morphology and anatomy: The analysed specimen has a smooth massive cormus (0.7 × 0.4 × 0.3 mm) composed of irregular and loosely anastomosed tubes ( Fig. 6A View Figure 6 ). No water-collecting tubes were observed. The body (cormus). C, tangential section of an attachment tube. D, triactine I. E, triactine II.

aquiferous system is asconoid. No granular cells were observed.

Skeleton: The skeleton has no special organization and it is exclusively composed of triactines ( Fig. 6B View Figure 6 ). The tubes that attach the sponge to the substrate are composed of parasagittal triactines ( Fig. 6C View Figure 6 ).

Spicules: Triactines I. Regular (equiangular and equiradiate). Actines are slightly conical with blunt to sharp tips ( Fig. 6D View Figure 6 ). Size: 87.5–130.0/7.5–10.0 µm. Triactines II. Parasagittal (equiangular). Actines are slightly conical with blunt to sharp tips ( Fig. 6E View Figure 6 ). The unpaired actine is longer than the paired ones. Size: 57.5–80.0/7.5 µm (paired actine) and 99.9–137.7/8.1– 8.8 µm (unpaired actine).

Ecology: The specimen was found underneath boulders and down to 10 m depth. No organisms associated with this species were observed.

Geographical distribution: Southern Caribbean (provisionally endemic to Curaçao, present study).

Molecular analysis: Clathrina was recovered as a monophyletic clade with high support in the ITS (pp = 1, b = 77) and C-LSU (pp = 0.90, b = 86) phylogenetic trees ( Figs 4 View Figure 4 , 5 View Figure 5 ). The ITS interspecific divergence ranged from 0.6 [ C. ramosa (Azevedo, Hajdu, Willenz & Klautau, 2009) vs. C. blanca (Miklucho-Maclay, 1868) ] to 11.2% ( C. rubra Sarà, 1958 vs. C. mutabilis Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017 ), whereas the C-LSU values varied from 0.5 ( C. ramosa vs. C. blanca ) to 12.9% ( C. cylindractina Klautau, Solé-Cava & Borojevic, 1994 vs. C. ramosa ).

Within the large clade of Clathrina , C. curacaoensis sp. nov. appeared as a different lineage and grouped with other four yellow clathrinas ( C. aurea Solé-Cava, Klautau, Boury-Esnault, Borojevic & Thorpe, 1991 , C. clathrus , C. lutea Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017 and C. luteoculcitella Wörheide & Hooper, 1999 ) and two white clathrinas ( C. sinusarabica Klautau & Valentine, 2003 and C. rowi Voigt, Erpenbeck & Wörheide, 2017 ) forming a well-supported cluster (ITS: pp = 1, b = 84 and C-LSU: pp = 0.99, b = 95).

Taxonomic remarks: Among the seven species of the genus Clathrina that are yellow in vivo, namely, C. aurea , C. chrysea Borojevic & Klautau, 2000 , C. clathrus , C. insularis Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017 , C. lutea Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017 , C. luteoculcitella and C. mutabilis , the latter is the species most resembling C. curacaoensis sp. nov. based on morphology.

Clathrina curacaoensis sp. nov. and C. mutabilis have a cormus composed of loosely anastomosed tubes and have water-collecting tubes (see below the description of C. mutabilis ). Their skeletons bear triactines with actines of different lengths (even including parasagittal triactines). However, in C. mutabilis these spicules (triactines II of Azevedo et al., 2017, size: 94.5–153.9/6.8–10.8 µm) occur in the whole cormus, whereas in C. curacaoensis sp. nov. (triactines II, size of the longest actine: 99.9–137.7/8.1–8.8 µm) they are restricted to the tubes used for attachment. Although being morphologically very similar, C. curacaoensis sp. nov. and C. mutabilis are molecularly distant. Clathrina curacaoensis sp. nov. clustered with six other Clathrina species, but not C. mutabilis .

Among the non-yellow clathrinas with stalk (former ‘guanchas’), C. arnesenae ( Rapp, 2006) is most similar morphologically to C. curacaoensis sp. nov. Nonetheless, the skeleton of C. arnesenae does not comprise regular triactines as is the case of C. curacaoensis sp. nov.; instead, it is only composed of parasagittal triactines with cylindrical actines.

More recently, Voigt et al. (2017) described a white Clathrina from the Red Sea, C. rotundata Voigt, Erpenbeck & Wörheide, 2017 . This species is very similar to C. curacaoensis sp. nov. as it also has a cormus composed of loosely anastomosed tubes, is devoid of a stalk and its skeleton is composed of parasagittal and regular triactines. However, in C. rotundata , the parasagittal triactines have cylindrical actines with rounded tips and are evenly distributed in the tube wall, whereas in C. curacaoensis sp. nov., those spicules have slightly conical actines with blunt to sharp tips and are restricted to the attachment tubes. Regarding spicule dimensions, in C. rotundata parasagittal triactines are thinner (5.0–7.0 µm) and regular triactines are smaller (15.0–73.0/4.0–8.0 µm) than those in C. curacaoensis sp. nov. (7.5–8.8 and 87.5–130.0/7.5–10.0 µm, respectively). Besides these morphological differences, C. rotundata and C. curacaoensis sp. nov. appeared as very distant lineages in the phylogenetic tree.