Arturia vansoesti, Cóndor-Luján & Louzada & Hajdu & Klautau, 2018

ARTURIA VANSOESTI View in CoL SP. NOV.

( FIG. 2 View Figure 2 ; TABLE 2)

Etymology: Named after Rob Van Soest in recognition of his dedicated work on the taxonomy of sponges, including those from Curaçao.

Type locality: Daai Booi , St. Willibrordus, Curaçao .

Material examined: Holotype. UFRJPOR 6720, Daai Booi , St. Willibrordus, Curaçao (12°12′43.12″N, 69°05′8.42″W) 5.2 m depth, coll. B. Cóndor-Luján, 19 August 2011 GoogleMaps . Paratype. UFRJPOR 6731, Sunset Waters, Soto (12°16′01.58″N, 69°07′44.85″W), 3–10 m depth, coll. B. Cóndor-Luján, 20 August 2011.

Diagnosis: Arturia with cormus composed of loosely anastomosed tubes and water-collecting tubes. The skeleton is mainly composed of spicules with cylindrical and distally undulated actines with rounded tips. Yellow in life.

Colour: Yellow in life ( Fig. 2A View Figure 2 ) and beige in ethanol ( Fig. 2B View Figure 2 ).

Morphology and anatomy: This species has a massive smooth cormus composed of irregular and loosely anastomosed tubes. The holotype measures 0.7 × 0.6 × 0.2 cm ( Fig. 2A, B View Figure 2 ). A water-collecting tube (2 × 1 mm) was present in the holotype (arrow in Fig. 2A View Figure 2 ). The aquiferous system is asconoid. No granular cells were observed.

Skeleton: The skeleton has no special organization and is composed of abundant triactines and rare tetractines ( Fig. 2C View Figure 2 ).

Spicules: Triactines. Regular (equiangular and equiradiate). Abundant. Actines are cylindrical, undulated at the distal part and with rounded tips ( Fig. 2D View Figure 2 ). Size: 72.5–90.0/3.8–5.0 µm. Tetractines. Regular (equiangular and equiradiate). Rare. Basal actines are cylindrical, distally undulated and with rounded to blunt tips ( Fig. 2E View Figure 2 ). The apical actine is the shortest actine ( Fig. 2F View Figure 2 ). It is straight and smooth; however, some curved actines were also found. It has sharp or blunt tips. Size: 60.0–90.0/3.8–5.0 µm (basal actine) and 25.0/3.8–5.0 µm (apical actine).

Ecology: This sponge was found in a cryptic habitat, underneath coral boulders, and down to 10 m depth. No associated organisms were found.

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

Taxonomic remarks: The genus Arturia now comprises 12 valid species: A. adusta ( Wörheide & Hooper, 1999) , A. africana ( Klautau & Valentine, 2003) , A. alcatraziensis (Lanna, Rossi, Cavalcanti, Hajdu & Klautau, 2007) , A. canariensis (Miklucho-Maclay, 1868) , A. darwinii ( Haeckel, 1870) , A. dubia ( Dendy, 1891) , A. hirsuta ( Klautau & Valentine, 2003) , A. spirallata Azevedo, Cóndor-Luján, Willenz, Hajdu, Hooker & Klautau, 2015 , A. tenuipilosa (Dendy, 1905) , A. trindadensis Azevedo, Padua, Moraes, Rossi, Muricy & Klautau, 2017 , A. tubuloreticulosa Van Soest & De Voogd, 2015 and A. vansoesti sp. nov. The species most resembling A. vansoesti sp. nov. in skeletal composition are A. canariensis from Canary Islands and A. tubuloreticulata from Indonesia, as the skeletons of these three species are mainly composed of triactines with cylindrical actines. Nonetheless, they have important differences.

The colour in vivo of A. canariensis is white, whereas in A. vansoesti sp. nov., it is yellow. Although spicule dimensions of these two species are very similar ( Table 2), the spicules of A. canariensis are less cylindrical and less undulated than those of A. vansoesti sp. nov. In A. vansoesti sp. nov., the spicules bear rounded tips, while those in A. canariensis are blunt.

Arturia tubuloreticulosa is orange in life and its cormus has several oscula, whereas the yellow A. vansoesti sp. nov. has water-collecting tubes. Furthermore, the spicules of the Curaçaoan species have rounded tips, while in the Indonesian species, they are sharp or blunt.

Arturia vansoesti sp. nov. is the second species in the genus to be described from the Caribbean Sea, as Pérez et al. (2017) recently listed A. hirsuta for the Eastern Caribbean (La Martinique).

GENUS BOROJEVIA KLAUTAU, AZEVEDO, CÓNDOR-LUJÁN, RAPP, COLLINS & RUSSO, 2013 View in CoL

Type species: Ascaltis cerebrum Haeckel, 1872 . Diagnosis: Calcinea in which the cormus comprises tightly anastomosed tubes. The skeleton contains regular (equiangular and equiradiate) triactines, tetractines, tripods and tetrapods. The apical actine of the tetractines has spines. Aquiferous system asconoid ( Klautau et al., 2013, emend.).

BOROJEVIA TENUISPINATA AZEVEDO, PADUA, MORAES, ROSSI, MURICY & KLAUTAU, 2017 View in CoL

( FIG. 3 View Figure 3 ; TABLE 3)

Synonymy: Borojevia tenuispinata Azevedo et al., 2017: 311–313 .

Material examined: UFRJPOR 6700 and UFRJPOR 6 7 0 8, D a a i B o o i, S t. W i l l i b r o r d u s, C u r a ç a o (12°12′43.12″N, 69°05′8.42″W), 3–5 m depth, coll. B. Cóndor-Luján, 18 August 2011.

Comparative material examined: Holotype of B. tenuispinata . UFRJPOR 6484, Cabeço da Tartaruga , São Pedro e São Paulo Archipelago, Brazil (0°54′57″N, 29°20′46″W), 8–12 m depth, coll. G. Rodríguez and F. Azevedo, 16 June 2011. GoogleMaps