Clathrina hondurensis, KLAUTAU & VALENTINE, 2003

CLATHRINA HONDURENSIS KLAUTAU & VALENTINE, 2003 View in CoL

( FIG. 8 View Figure 8 ; TABLE 6)

Synonymy: Clathrina hondurensis Klautau & Valentine, 2003: 46 .

Material examined: UFRJPOR 6732, Porto Mari , St. Willibrordus, Curaçao (12°13′6.62″N, 69°05′13.26″W), 7.9 m depth, coll. B. Cóndor-Luján, 20 August 2011 GoogleMaps .

C o m p a r a t i v e m a t e r i a l e x a m i n e d: H o l o t y p e o f C. h o n d u r e n s i s. B M N H 1 9 3 8.3.2 8.4, T u r n e f f e, Belize, Caribbean Sea, coll. J. H. Borley, 20–22 March 1935 .

Colour: White in life ( Fig. 8A View Figure 8 ) and yellow to light brown in ethanol ( Fig. 8B View Figure 8 ).

Morphology and anatomy: The specimen is massive and it measures 1.4 × 1.0 × 0.2 cm ( Fig. 8A View Figure 8 ). The surface is smooth and the consistency is compressible. The cormus is composed of irregular and tightly anastomosed tubes ( Fig. 8B View Figure 8 ). No water-collecting tubes were observed. The aquiferous system is asconoid. No granular cells were observed.

Skeleton: The skeleton has no special organization ( Fig. 8C View Figure 8 ) and is composed of triactines and rare trichoxeas ( Fig. 8D View Figure 8 , arrow).

Spicules: Trichoxeas. Straight and very slender ( Fig. 8D View Figure 8 ). Most of them are broken. The size of the unique entire trichoxea found is 325.0/2.5 µm. Triactines. Regular (equiangular and equiradiate). Actines are conical with sharp tips ( Fig. 8E View Figure 8 ). Size: 100.0–212.5/13.6–25.0 µm.

Ecology: This specimen was collected underneath coral boulders at 7.9 m depth. No associated organisms were found.

Geographical distribution: Southwestern Caribbean ( Belize, Klautau & Valentine, 2003) and Southern Caribbean ( Curaçao, present study) ecoregions.

Taxonomic remarks: The external morphology and the shape of the triactines observed in the specimen from Curaçao are similar to C. hondurensis from Turneffe. However, in the original description of that species, trichoxeas were not reported and after re-examination of the slides of the holotype, we confirmed the absence of these spicules. As seen in other species, the presence of trichoxeas may not constitute a diagnostic character, as they seem to be plastic characters in Clathrina ( Azevedo et al., 2017) .

Regarding spicule dimensions, although the triactines of the specimen from Curaçao can attain slightly larger sizes (100.0–212.5/13.6–25.0 µm) compared to the holotype of C. hondurensis (105.6–156.0/12.0– 19.2 µm, taken from Klautau & Valentine, 2003), they are in the same size range.

It is important to point out that C. hondurensis was originally described based on a single specimen. Considering this, the presence of trichoxeas and of slightly larger triactines in the specimen from Curaçao could be attributable to intraspecific variation.

Recently, Klautau et al. (2016) considered the possible synonymy of C. hondurensis and C. primordialis ( Haeckel, 1872) . In fact, both species have similar morphology and spicule size range. Nonetheless, it is possible to recognize thicker spicules in C. hondurensis (holotype: 12.0–19.2 µm) than in C. primordialis (holotype: 8.0–12.0 µm, Table 6). Based on this subtle but consistent difference, we decided to maintain C. hondurensis as a valid species and identify the Curaçaoan specimen as C. hondurensis .

Rützler et al. (2014) recorded C. hondurensis from another Belizean locality ( Belize barrier reef near Carrie Bow); however, the skeleton of that specimen was composed of shorter and thinner triactines (85.0– 100.0/8.0–12.0 µm) and thus, it does not seem to correspond to C. hondurensis .

CLATHRINA INSULARIS AZEVEDO, PADUA, MORAES, ROSSI, MURICY & KLAUTAU, 2017 View in CoL

( FIG. 9 View Figure 9 ; TABLE 7)

Synonymy: Clathrina insularis Azevedo et al., 2017: 317–318 .

Material examined: UFRJPOR 6737, Playa Jeremi , Soto, Curaçao (12°19′43.73″N, 69°09′07.80″W), 14.9 m depth, coll. B. Cóndor-Luján, 22 August 2011 GoogleMaps .

Additional material re-analysed: UFRJPOR 6533, Cagarras , Fernando de Noronha Archipelago, Pernambuco, Brazil (03°48′34.59″S, 32°23′27.91″W), 15 m depth, coll. F. Azevedo and G. Rodríguez, 27 June 2011 GoogleMaps . UFRJPOR 6530 and UFRJPOR 6537, Ilha do Meio , Fernando de Noronha Archipelago, Pernambuco, Brazil (03°49′5.88″S, 32°23′36.6″W), 15 m depth, coll. F. Azevedo and G. Rodríguez, 27 June 2011 GoogleMaps .

Comparative material examined: Holotype of C. insularis . UFRJPOR 6532, Cagarras , Fernando de Noronha, Pernambuco, Brazil (03°48′34.59″S, 32°23′27.91″W), 15 m depth, coll. F. Azevedo and G. Rodríguez, 27 June 2011. GoogleMaps