Ascandra cf. crewsi Van Soest & De Voogd, 2015

Klautau, Michelle, Lopes, Matheus Vieira, Guarabyra, Bruna, Folcher, Eric, Ekins, Merrick & Debitus, Cécile, 2020, Calcareous sponges from the French Polynesia (Porifera: Calcarea), Zootaxa 4748 (2), pp. 261-295 : 267-269

publication ID	https://doi.org/ 10.11646/zootaxa.4748.2.3
publication LSID	lsid:zoobank.org:pub:661CD94A-130B-4BD8-B201-28B079815618
DOI	https://doi.org/10.5281/zenodo.3704828
persistent identifier	https://treatment.plazi.org/id/6A74544A-FFEA-7257-FF63-581EFE10FD26
treatment provided by	Plazi
scientific name	Ascandra cf. crewsi Van Soest & De Voogd, 2015
status

Treatment

Ascandra cf. crewsi Van Soest & De Voogd, 2015 View in CoL

( Fig 2 View FIGURE 2 ; Table 2 View TABLE 2 )

Synonym. Ascandra crewsi, Van Soest & De Voogd 2015: 36 .

Material examined: UFRJPOR 6462 = MNHN-IP- 2018-33 — Tairineneva , Raiatea, Society Islands, station SR02 (16° 45.326’ S– 151° 29.827’ W), depth: 15 m, coll. C. Debitus GoogleMaps , 12/VIII/2009, P53. UFRJPOR 6463 = MNHN- IP- 2018-34, UFRJPOR 6464 = MNHN-IP- 2018-35 — Tahiti , Society Islands, station ST22 (17° 32.485’ S– 149° 35.205’ W), depth: 14 m, coll. C. Debitus GoogleMaps , 29/ V /2009, P23. UFRJPOR 8916 = MNHN-IP- 2018-57 — Tahiti , Society Islands, station ST27 (17°46.642’ S– 149°24.236’ W), coll. S. Petek GoogleMaps , 13/IV/2013, depth: 30 m, P485. UFRJPOR 8917 = MNHN-IP- 2018-58 — Tahiti , Society Islands, station ST29 (17°53.052’ S– 149°11.411’ W), coll. S. Petek GoogleMaps , 14/IV/2013, depth: 20 m, P507. UFRJPOR 8920 = MNHN-IP- 2018-61 — Tahiti , Society Islands, station ST59 (17°47.343’S– 149°27.229’W), coll. C. Debitus GoogleMaps , 13/IV/2013, depth: 15 m.

Colour. White alive and white or light brown in ethanol ( Fig 2A View FIGURE 2 ).

Morphology and anatomy. Cormus delicate, formed by large, irregular, loosely anastomosed and ramified tubes with one or several oscula at the end of larger tubes (water-collecting tubes; Fig 2A View FIGURE 2 ). Aquiferous system asconoid. The skeleton is composed of two size categories of tetractines ( Fig 2B View FIGURE 2 ), of which the larger is rare, and by small rare triactines.

Spicules ( Table 2 View TABLE 2 )

Tetractines I. Large. Regular (equiangular and equiradiate) or sagittal. Actines are conical with sharp tips ( Fig 2C View FIGURE 2 ). The sagittal spicules sometimes have curved paired actines. The apical actine is cylindrical, very long, sharp, smooth and frequently curved but straight apical actines are also present ( Fig 2C View FIGURE 2 ). Size: 162.0–218.7/ 16.2–27.0 µm (basal), 75.0–150.0/ 5.0–15.0 µm (apical).

Tetractines II. Small. Regular (equiangular and equiradiate) or sagittal. They are very similar to Tetractines I, but a little smaller and with thinner actines ( Fig 2 D View FIGURE 2 ). Size: 110.7–178.2/ 10.8–16.2 µm (basal), 17.5–234.9/ 1.3–9.5 µm (apical).

Triactines. Rare, small. Regular (equiangular and equiradiate) or sagittal. Actines are conical with sharp tips ( Fig 2E View FIGURE 2 ). The sagittal spicules sometimes have curved paired actines. Size: 77.5–137.5/ 8.8–10.0 µm.

Ecology. This sponge was found in holes or below dead corals, in a slightly muddy environment.

Geographical distribution. Papua New Guinea (type locality; Van Soest & De Voogd 2015) and Society Islands (Raiatea and Tahiti—present work) .

Remarks. Eleven species of Ascandra are currently known: Ascandra falcata Haeckel, 1872 from Lesina, Adriatic Sea (the type species of the genus); A. ascandroides ( Borojević, 1971) from Rio de Janeiro, Brazil; A. atlantica ( Thacker, 1908) from Cape Verde Islands; A. biscayae ( Borojević & Boury-Esnault, 1987) from Bay of Biscay; A. brandtae ( Rapp, Göcke, Tendal & Janussen, 2013) from the Weddell Sea, Antarctica; A. contorta ( Bowerbank, 1866) from the Mediterranean Sea; A. corallicola ( Rapp, 2006) Trondheimsfjord , Norway; A. crewsi Van Soest & De Voogd, 2015 from Wahoo, Papua New Guinea; A. densa Haeckel, 1872 from South Australia; A. kakaban Van Soest & De Voogd, 2015 from Kalimantan, Indonesia; and A. minchini Borojević, 1966 from the Mediterranean Sea. Considering cormus and skeleton composition (triactines and two size categories of tetractines), the specimens from the French Polynesia are more similar to A. crewsi and A. kakaban . The latter, however, has the same proportion of triactines and tetractines, while A. crewsi has very few triactines, like our specimens. Therefore, although the spicules of the specimens from French Polynesia are a little larger and have tetractines with actines more conical than those of A. crewsi [ A. crewsi —Triactines: 140.0˗150.0/ 10.0˗12.0 µm; Tetractines I: 159.0˗206.4˗246.0/ 15.0˗18.8˗21.0 µm (basal actines), 181.0˗226.3˗279.0/ 13.0˗15.3˗17.0 µm (apical actine); Triactines II: 54.0˗90.2˗117.0/ 7.0˗7.3˗8.0 µm (basal actines), 62.0˗95.8˗114.0/ 2.5˗3.1˗ 3.5 µm (apical actine)], we think they can be conspecific.