Ascaltis reticulum ( Schmidt, 1862 )

Klautau, Michelle, Imešek, Mirna, Azevedo, Fernanda, Pleše, Bruna, Nikolić, Vedran & Ćetković, Helena, 2016, Adriatic calcarean sponges (Porifera, Calcarea), with the description of six new species and a richness analysis, European Journal of Taxonomy 178, pp. 1-52 : 7-10

Ascaltis reticulum ( Schmidt, 1862) Fig. 2 ; Table 2

Nardoa reticulum Schmidt, 1862: 18 .

Tarrus reticulatus Haeckel, 1870: 244 .

Nardopsis reticulum Haeckel, 1870: 247 .

Ascandra reticulum Haeckel, 1872: 87 .

Olynthus reticulum Haeckel, 1872: 88 .

Clistolynthus reticulum Haeckel, 1872: 88 .

Soleniscus reticulum Haeckel, 1872: 88 .

Nardorus reticulum Haeckel, 1872: 88 .

Tarrus reticulum Haeckel, 1872: 88 .

Auloplegma reticulum Haeckel, 1872: 88 .

Ascometra reticulum Haeckel, 1872: 88 .

Ascandra retiformis Haeckel, 1872: 88 .

Ascandra reticulata Haeckel, 1872: 88 .

Clathrina reticulum Minchin, 1896: 359 .

Ascandra hermesi Breitfuss, 1897a: 39 .

Leucosolenia hermesi Dendy & Row, 1913: 722 .

Nardoa reticulum – Schmidt 1869: 91; 1870: 73.

Ascandra reticulum – Vosmaer 1881: 5. — Lendenfeld 1891: 39. — Breitfuss 1897b: 214; 1898a: 23; 1898b: 92. — Brøndsted 1914: 530. Leucosolenia reticulata – Dendy & Row 1913: 723. — Breitfuss 1932: 243.

Leucosolenia reticulum – Dendy & Row 1913: 723. — Breitfuss 1930: 275; 1932: 243; 1935: 14. — Topsent 1934: 9; 1936: 22. — Hôzawa 1940: 32. — Arndt 1941: 4. — Tanita 1942: 82; 1943: 386. — Burton 1963: 200.

Ascandra retiformis – Breitfuss 1932: 243.

Leucosolenia hermesi – Tanita 1942: 82.

Clathrina reticulum – Borojević 1967: 189. — Borojević & Peixinho 1976: 993. — Borojević & Boury- Esnault 1987: 12. — Klautau & Valentine 2003: 36. — Longo & Pronzato 2011: 230. — Muricy et al. 2011: 34.

Ascaltis reticulum – Klautau et al. 2013: 452.

Original type locality

ADRIATIC SEA: Zara (Croatian: Zadar) and Sebenico (Croatian: Šibenik).

Type specimen

FRANCE: Banyuls-sur-Mer, Pyrenées, E.A. Minchin Collection ( BMNH 1896.9.15.13, neotype proposed by Klautau & Valentine 2003).

Material examined

ADRIATIC SEA: near the Island of Čiovo, 43°28'58.5" N, 16°21'25.6" E, 5 m, 5 Nov. 2010, collected by B. Pleše and V. Nikolić (PMR-13739 = UFRJPOR 6870).

Colour

White in life and white in ethanol.

Description

Cormus is composed of regular and tightly anastomosed tubes. Water-collecting tubes are present ( Fig. 2A ).As the specimen was fragmented, it was not possible to observe the pseudoatrium. The skeleton is composed of one category of triactines, one of tetractines and diactines. Diactines are organised in tufts of two to five spicules, perpendicularly disposed in the tubes ( Fig. 2B ). Triactines are the most abundant spicules.

Spicules ( Table 2 )

TRIACTINES. Regular (equiangular and equiradiate). Actines are slightly conical to cylindrical, with sharp tips ( Fig. 2C ). Size: 88.2/ 9.5 µm.

TETRACTINES. Regular (equiangular and equiradiate). Actines are slightly conical to cylindrical, with sharp tips ( Fig. 2D ). The apical actine is very thin and shorter than the basal ones. It is cylindrical and blunt, covered by abundant tiny spines ( Fig. 2E ). Size: 79.1/ 8.8 µm (basal actine); 41.9/ 3.2 µm (apical actine).

DIACTINES. Slightly curved. The tip that protrudes through the surface is lanceolated ( Fig. 2F ). Trichoxeas are also present on the surface of the tubes. Size: 106.3/ 4.9 µm.

Ecology

Specimens were collected on a vertical, shaded hard limestone bottom.

Remarks

Klautau et al. (2013) proposed to transfer this species to the genus Ascaltis based mainly on morphological, but also on molecular data. Although the type species of this genus ( A. lamarcki Haeckel, 1870 ) was not included in the molecular dataset, A. reticulum did not group with any of the included genera ( Fig. 16 ). Besides, morphologically it is more similar to Ascaltis than to any other genus. Therefore, although the classification of A. reticulum in the genus Ascaltis must still be verified regarding the type species of the

genus, it was morphologically and molecularly proved that it cannot be included in the genus Clathrina . Hence, we keep the proposition of Klautau et al. (2013) and name this species A. reticulum .

This is the first time that spines were observed on the apical actine of the tetractines of A. reticulum . For that reason, we examined the neotype of this species and detected spines as well. They are abundant and very small. We also observed a great variation in the size of the diactines, which are much larger in the neotype (102.0–212.2 (±54.1)–306.0 /14.3 (±5.1) µm).

Figures

Fig. 2. Ascaltis reticulum (PMR 13739 = UFRJPOR 6870). A. Specimen in situ. B. Section showing the perpendicular arrangement of diactines. C. Regular triactines. D. Regular tetractine. E. Apical actine of a tetractine covered with short spines. F. Diactine.

Fig. 16. Maximum likelihood (ML) tree based on ITS1-5.8S-ITS2 rDNA sequences of Calcinea. Bayesian posterior probabilities (PP) and bootstrap values (BS) are given near the branches (PP/BS; when>0.50). Adriatic specimens are written in bold; *Adriatic specimens obtained during this study; **Mediterranean specimens of Borojevia cerebrum; ***Brazilian specimens of Clathrina conifera.