Ernstia adunca, Fontana & Cóndor-Luján & Azevedo & Pérez & Klautau, 2018

Fontana, Tayara, Cóndor-Luján, Báslavi, Azevedo, Fernanda, Pérez, Thierry & Klautau, Michelle, 2018, Diversity and distribution patterns of Calcareous sponges (subclass Calcinea) from Martinique, Zootaxa 4410 (2), pp. 331-369 : 352-354

Ernstia adunca sp. nov.

( Figure 10 , Table 10)

Diagnosis. Ernstia with an apical actine strongly curved, forming a hook.

Etymology. From the Latin aduncus (= hooked, curved), for the shape of the apical actine of the tetractine.

Type Locality. Le Rocher du Diamant, Martinique.

Synonyms. Ernstia sp. nov.: Pérez et al. 2017: 13.

Type Material. ( Three specimens) Holotype: UFRJPOR 7644, Le Rocher du Diamant, Martinique (14°26.556' N – 61°2.408' W), collected by F. Azevedo, 25 April 2015, 18.8 m depth . Paratypes: UFRJPOR 7422, Pointe Burgos , Anses d'Arlet, Martinique (14°29.787' N – 61°5.351' W), collected by M. Klautau and T. Pérez, 0 6 December 2013. UFRJPOR 7672, Le Rocher du Diamant, Martinique (14°26.556' N – 61°2.408' W), collected by F. Azevedo, 25 April 2015, 18.8 m depth.

Colour. Yellow alive and light beige in ethanol.

Description. Clathroid body formed by thin, irregular and loosely anastomosed tubes ( Figure 10A ). No cells with granules. Water-collecting tubes are present and they are very large and conspicuous ( Figures 10A–C ). Aquiferous system asconoid.

Skeleton. The skeleton has no special organisation ( Figure 10D ) and is formed by two categories of triactines and one of tetractines. Triactines and tetractines are present in the same proportion.

Spicules ( Table 10).

*From van Soest & de Voogd (2015).

Triactine I: Regular or subregular. Actines are cylindrical and straight or slightly undulated, with blunt tips ( Figure 10E ). Size: 27.5–65.0/2.5–5.0 µm.

Triactine II: Regular. Actines are conical to slightly conical with sharp or blunt tips ( Figure 10F ). Size: 81.1– 118.9/5.4–8.1µm.

Tetractine: Similar to the triactine I ( Figure 10G ). The apical actine is thicker than the basal ones and it is curved at the distal part ( Figure 10H ). Size: Basal actines: 73.0–110.8/5.4–6.7 µm. Apical actine: 59.5–94.6/9.0 µm.

Ecology. Specimens of this species were found protected from the sunlight.

Geographical distribution. Martinique.

Remarks. The only species of Ernstia with an apical actine strongly curved as in E. adunca sp. nov. is E.

chrysops Van Soest & De Voogd, 2015 from Indonesia. The difference is that in E. adunca sp. nov. the actine turns to the basal actines (360o), forming a hook ( Figures 10F–H ), while in E. chrysops it curves 90o. In addition, not all apical actines of E. chrysops are curved, while in E. adunca sp. nov., all of them are. Besides, the spicules of E. chrysops are larger than those of E. adunca sp. nov. ( Table 10). In our phylogenetic tree ( Figure 17 ), E. adunca sp. nov. did not present intraspecific variation (boostrap 100% and p-distance of 0%), and was closer to E. arabica with bootstrap of 96% and p-distance ranging from 5.6% to 5.9%.

Figures

FIGURE10. Ernstiaadunca sp.nov.(UFRJPOR 7644).A.Specimen in situ (UFRJPOR 7422, picture previously publishedin Pérez et al.2017).B. Specimen inethanol.C. Water-collecting tube ofthe specimenUFRJPOR 7672.D. Tangential section.E. Triactine I. F.Triactines II. G. Tetractine.H. Apical actine (arrow) of a tetractine.

FIGURE17. Maximum Likelihood tree of the C-LSU nuclear marker.Bootstrap values are shown on thebranches.Sequences generatedin the present study are marked with an asterisk.