Caminella intuta ( Topsent, 1892 )

Cárdenas, Paco, Vacelet, Jean, Chevaldonné, Pierre, Pérez, Thierry & Xavier, Joana R., 2018, From marine caves to the deep sea, a new look at Caminella (Demospongiae, Geodiidae) in the Atlanto-Mediterranean region, Zootaxa 4466 (1), pp. 174-196 : 177-187

Caminella intuta ( Topsent, 1892)

( Figures 2–6 , Table 1)

Synonyms.

Cydonium intutum Topsent, 1892 : Topsent 1892, p. XVIII.

Isops intuta ( Topsent, 1892) : Topsent 1893, p. XLIII; Topsent 1894, p. 336, pl. XI, pl. XVI; Lendenfeld 1903, p. 95–96; Sarà 1961, p. 31; Boury-Esnault 1971, p. 296; Pouliquen 1972, Table 1; Templado et al. 1986, Table 1.

Isops intutus ( Topsent, 1892) : Vosmaer 1933, p. 145.

Isops intuta ( Vosmaer, 1894) : Maldonado 1992, Table 1 (mistake in authority).

Caminella intuta ( Topsent, 1892) : Cárdenas et al. 2011; Sitjà & Maldonado 2014, Table 2.

Isops maculosus Vosmaer, 1894 : Vosmaer 1894, p. 273–274.

Isops maculosa Vosmaer, 1894 : Lendenfeld 1903, p. 96.

Caminella loricata Lendenfeld, 1894 : Lendenfeld 1894, p. 150–151, pl. II, pl. III, pl. VIII; Lendenfeld 1903, p. 89–90.

Not Isops intuta ( Topsent, 1892) : Boury-Esnault et al. 1994, p. 41 = Geodia sp. (this study)

Holotype. MNHN DT-2290 (slide with sections, in bad state), Cap l’Abeille, Banyuls , France, 25-30 m.

Material examined. Caminella intuta . France: SME, collection ‘Topsent’, box 1, slide#12 labeled “ Isops intuta ”, Banyuls-sur-Mer (type locality), dredge; SME #90S, dry piece and slide, 17.03.1958, Le Petit Congloué, Archipel de Riou, Marseille, cliff facing NE, 40 m, coll. J. Vacelet; SME #193S, wet specimen and slide, 26.08.1998, Gameau cave, La Ciotat, 6-8 m, preserved in formalin, coll. J. Vacelet; SME PL617PC-7 ( Fig. 2C, 2E ) and PL617PC-10b, 18.05.2016, Cosquer cave, Calanque de la Triperie, Parc National des Calanques, coll. P. Chevaldonné, ethanol 96 %; Lebanon: SME 21/09/2002 -56a, 5/07/2003 -1 (sac 9), 13/07/2003 -2, preserved in formalin, Chak El Hatab ( north of Selaata, Lebanon), " lithistid cave ", in dark area, 2-3 m, colls. T. Pérez and J. Vacelet; SME field# 080524 - Lb 2-03, 24.05.2008, Chak El Hatab, “lithistid cave”, 2 m, coll. T. Pérez, ethanol; Alboran Sea: field# Sp175, station BV 41, 35.99362, -2.86795, 102-112 m, beam trawl, INDEMARES- ALBORAN, 21.07.2012, coll. S. Gofas, identified by Sitja & Maldonado (2014), preserved in formalin ( Fig. 2F ); Portugal: ZMAPOR 21653 , field# B.05.09.268, Gruta do Carreiro Maldito, Berlengas, Portugal, 6-8 m, 20.09.2005, ethanol 96%, coll. A. Cunha ( Fig. 2D , 3F–G ).

Isops maculosus , lectotype (here designated), RMNH Por 644 (not seen), Gulf of Naples, between Capri and Naples, 150-200 m, wet specimen labeled as ' Isops intutus Tops. Corallieri, 17 Mei 1884 coll. Vosmaer N.249', and 18 slides, some of which are labeled Isops maculosus , but all have the number 249. Slides are mostly histological sections, but two are spicule slides. According to GBIF records from the RMNH collection (https://www.gbif.org/ occurrence/search?taxon_key=5892880), there are at least seven other paralectotypes (here designated): RMNH Por 78, 645, 646, 647, 648, 649, 650; BMNH 1955.3.24.2 (seen), two fragments of paralectotype RMNH Por 647 (~2.5 x 1.5 cm), 12.12.1890, Gulf of Naples.

Caminella loricata , holotype (not seen), ZMB Por 2423, Lesina (=Hvar), Adriatic Sea, Croatia, one small piece 1 cm x 0.5 cm, purchased in 1897, no slides; NHMW-3Zoo-EV-MP345 ( Fig. 3A, 3C–E ), slide from holotype with a thick section (seen high resolution pictures); NHMW-3Zoo-EV-MP346 ( Fig. 3B ), slide from holotype with histological sections (seen high resolution pictures).

Geodia sp. SME, Balgim slide box ‘Tetractinellida’, three slides labeled ‘CP–63 (185)’ (two spicule preparations and one piece of cortex), off Morocco, 1510 m, originally identified as Isops intuta by M. J. Uriz (Boury-Esnault et al. 1994).

External morphology and skeleton organization. ( Figs. 2–3 ) Massive subglobular, up to 10 cm wide ( Fig. 2C ) with smooth, clean surface. Cave specimens from France and Portugal area are brown, to dark brown ( Fig. 2A, 2C, 2D ). Cave specimens from Lebanon ( Fig. 2B ) are pure white (small specimens), white to cream or light brown (large specimens). Deep-sea specimens are cream-colored to brown. Internal color is white to light brown. Colors are retained in ethanol and formalin. One to several uniporal oscules (0.2–2 mm in diameter) can be present, each leading into a cloaca ( Fig. 3F ). Cave specimens from Lebanon generally have a single oscule at the top, more rarely two or three, while other cave specimens often have several oscules. Oscules can have a slightly elevated margin in life, especially visible in underwater photographs ( Fig. 2A, 2B ), often flush with surface after preservation ( Fig. 2E ). Surface punctured by numerous uniporal pores (20–200 µm in diameter in cave specimens; 20–55 µm in deep- sea specimen), which can have elevated surrounding walls ( Fig. 2E ), or not ( Fig. 2F ). Oscules and pores can be surrounded by a conspicuous dark ring (especially in cave specimens) ( Fig. 2A, 2C ), or not (deep-sea specimens) ( Fig. 2F ). Consistency fleshy.

The cortex is thin (0.2–0.5 mm thick), more or less flexible and easily detachable from the underlying choanosome. The ectocortex is composed of a dense aggregation of spherasters/spherules while the endocortex is made of sterrasters ( Fig. 3D–E ). Dichotriaenes support the cortex, but do not cross it ( Fig. 3G ). In the choanosome, a few oxeas are more or less radially organized ( Fig. 3F–G ). In the choanosome, oxyasters and sterrasters are common while spherasters/spherules are rare and predominantly found around the canals.

Spicules. ( Figs. 4–6 ) ( Table 1) (a) oxeas, a few styloids, 900– 2500 x 6 -50 µm; (b) dichotriaenes (rhabdome: 370– 2000 x 12 –60 µm; protoclad: 60–237 µm; deuteroclad: 25–410 µm), rarely orthotriaenes; (c) sterrasters, spherical to oval, 40–84 µm, surface without clear rosettes, instead the actins build bridges between them making a brain-like surface, which is then covered with small warts; immature sterrasters have blunt actins covered with small branches that sometimes link two actins together making a honeycomb surface (similar to Placospongia selenasters). From here on we will distinguish ‘young’ (not fully grown) from ‘immature’ (fully grown but underdeveloped) sterrasters; (d) oxyasters, 3–8 actins, 10–36 µm in diameter, actins are finely acanthose and blunt at the very tip; center is more or less developed; (e) spiny spherasters to spherules, different ratios depending on the specimens, sometimes with very irregular spherasters, 3–15 µm in diameter.

We observed four types of spicule phenotypes depending on the origin of the specimens. 1) Cave specimens from France and Portugal, as well as C. loricata from Croatia had immature sterrasters associated with irregular to regular spherasters, which rarely become spherules ( Figs. 3E , 4 ). Dichotriaenes can also be irregular; orthotriaenes are occasionally found. 2) Specimens from shallow-water but deeper (25–40 m) and not in caves (specimens from the type locality identified by Topsent and from 40 m in Marseille) have immature sterrasters associated with irregular to regular spherasters, many of which are spherules. 3) Cave specimens from Lebanon (all coming from the same cave) had mature sterrasters and only spherules. Megascleres are larger and robust ( Fig. 5 ). 4) Deep-sea specimens ( Isops maculosus paralectotype and specimen from the Alboran Sea) had mature sterrasters with regular spherasters, which have on average shorter actins, and often become spherules ( Fig. 6 ).

Bathymetric range. In caves, C. intuta lives in semi-dark to dark areas, where it can be found as shallow as 2 m depth. Outside caves, it has been recorded from 25–30 m in Banyuls-sur-Mer ( Topsent, 1892) to 300 m in the Alboran Sea (Templado et al. 1986).

DNA barcoding. COI. ZMAPOR 21653 ( HM592740 ) and cave specimen from Lebanon (080524 -Lb2-03) had a 100% identical COI ( MH477613 ). 28S (C1-D2). ZMAPOR 21653 ( HM592804 ) and cave specimen from Lebanon (080524 -Lb2-03, MH478114 ) were 100 % identical. Both had a 5 bp difference with PL617PC-10b from Cosquer cave ( MH478115 ). 18S. ZMAPOR 21653 ( MH478118 ). ZMAPOR 21653 was submitted to the Sponge Barcoding Project (http://www.palaeontologie.geo.uni-muenchen.de/SBP/) with accession number 1777.

Remarks. Suspicions of synonymy with Isops maculosus and Caminella loricata were raised early on by Topsent (1895, p. 580–581) who suggested that i) Isops maculosus might be a synonym of Isops intuta , although its colour seemed different and its sterrasters larger, ii) Caminella loricata might be a synonym of Isops intuta since the ‘microdesmen’ described by Lendenfeld (1894) were probably spherasters. However, Topsent (1895) did not conclude since he had not seen type material and Vosmaer (1894) had not given any measurements or illustrations of I. maculosus . This issue was later taken up by Vosmaer (1933), finally giving some spicule measurements of I. maculosus . He concluded that his species, I. maculosus and C. loricata , are junior synonyms of I. intuta . Once again, these conclusions were not based on the comparison of type material. The present study is the first one to examine the type material from Cydonium intutum , Isops maculosus , and Caminella loricata . We confirm that I.

maculosus and C. loricata are junior synonyms of Caminella intuta . And yet, we do note some external morphology and spicule differences within C. intuta specimens, which will be discussed below.

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The singularity of Caminella sterrasters was foreseen by Topsent (1894) who noted that sterrasters had complex and ornate surfaces. Later Vosmaer (1933, p. 148) very accurately observed that it “appears as if spines of neighboring actins were fused together” but concludes this is probably not the case and that “the truth being that they are only crowded close together”. The unique pattern and microstructures of the sterrasters’ surfaces is revealed here for the first time with SEM ( Figs. 4–7 , 9 ). The surface of Caminella sterrasters is indeed quite different from Geodia sterrasters which have characteristic star shaped structures called ‘rosettes’ (4–8 µm in diameter) which do not fuse with one another, and can be smooth or covered with small warts (Cárdenas et al. 2009; Cárdenas et al. 2013). In Caminella , actins produce at their tips, small perpendicular bridges ( Fig. 4D ) that reach towards the other actins, creating a complex fused network, which gives first a honeycomb-like structure (especially when observed with an optical microscope) then a brain-like structure when these bridges thicken. Finally, these surfaces are covered with small warts. Interestingly, all cave specimens ( Fig. 4 ) except the ones from Lebanon have immature sterrasters, which are very similar to immature sterrasters observed in shallow-water Geodiidae in Norway: Pachymatisma normani Sollas, 1888 and Geodia barretti Bowerbank, 1858 ( Cárdenas & Rapp 2013). Cárdenas & Rapp (2013) hypothesize that the lower silica concentration in shallow waters is primarily responsible for the immature sterrasters and we may contemplate a similar hypothesis for most cave specimens, which are also amongst the shallowest specimens (6–8 m). Disrupted spiculogenesis is particularly important in the cave specimen from Berlengas, Portugal, where the sterrasters are the smallest ( Table 1) and dichotriaenes quite irregular. On the contrary, the Lebanese specimens have larger and fully mature sterrasters ( Fig. 5 ) and significantly thicker spicules ( Table 1), which may be linked to higher availability of dissolved silica. Interestingly, the cave where the specimens were collected was densely populated by two species of lithistids (Pérez et al. 2004), which may support this hypothesis, since lithistids have higher needs of silica than other demosponges. Spicule variations between Mediterranean caves have already been observed for the lithistid tetractinellid Discodermia polymorpha (Pisera & Vacelet 2011) but in none of those cases did it seem clear that this species was lacking silica. Shallow-water C. intuta living outside caves and slightly deeper (25–40 m) still have immature sterrasters. Only deeper specimens (>100 m) ( Fig. 6 ), living in waters where silica availability is usually higher, share the same mature sterrasters as the cave specimens from Lebanon. This is in accordance with other Geodiidae , where mature sterrasters are usually found below 40 m ( Cárdenas & Rapp 2013). The cortical spheraster morphology also seems to be affected by environmental parameters, possibly silica availability: in cave specimens with immature sterrasters, spherasters are irregular, with small centers, and therefore few spherules; deep-sea specimens have more regular spherasters with larger centers (thus hiding the actins and making spherules); Lebanese specimens reach the extreme of having only spherules, probably indicative of high silica availability. To conclude, ectocortical microsclere morphology seems to be influenced by silica availability, such as in P. normani , but unlike in G. barretti ( Cárdenas & Rapp 2013). We wonder whether this means that microscleres in Erylinae ( C. intuta , P. normani ) and Geodinae have different origins and/or spiculogenesis mechanisms.

Like G. barretti and P. normani , C. intuta may be a deep-sea species that manages to survive in shallow-waters, despite lacking silica most of the time. Actually, C. intuta , like several other Mediterranean tetractinellids (e.g. Penares helleri (Schmidt, 1864) , Penares euastrum (Schmidt, 1868) , Geodia cydonium (L., 1767), Caminus vulcani (Schmidt, 1862) , Calthropella pathologica (Schmidt, 1868) , Thrombus abyssi (Carter, 1873) , Alectona millari Carter, 1879 , Discodermia polymorpha Pisera & Vacelet, 2011, Neoschrammeniella bowerbanki ( Johnson, 1863) and Neophrissospongia nolitangere (Schmidt, 1870)) (Pisera & Vacelet 2011; Pouliquen 1972) are typically found from marine caves to the deep sea. Currently, we do not have enough data from either population of C. intuta to assess the connectivity between shallow and deep populations. However, Vosmaer (1933) did note differences between his deeper specimens and the shallower specimens of Topsent and Lendenfeld, especially the absence of raised openings and surrounding dark rings around them. Our morphological observations confirm there are differences in external morphology: the deep specimens (from the Alboran Sea and Gulf of Naples) share the same dull color, the absence of a brown ring around the openings, and openings without walls and very small pores (20– 50 µm).

The significantly different 28S from one of the Cosquer Cave specimen (5 bp difference) is rather surprising since the Lebanese and Portuguese specimens have identical 28S. These underwater caves are only 20,000 years old (before, they were above water) so we doubt it could be due to a speciation event. Either i) the population that colonized this cave originated from a very different population than the ones present in Portugal and Lebanon (maybe from the deep sea) or ii) we sequenced a variant of 28S in this species, since intragenomic 28S polymorphism has been observed in some demosponges (Plotkin et al. 2017). Unfortunately, we did not manage to sequence COI from the Cosquer Cave specimens, but the morphology clearly suggests it is C. intuta . More cave and deep-sea specimens need to be examined and sequenced, especially for a population genetics study that should unveil the genetic ties between the marine cave, mesophotic zone and deep populations.

We noticed that the surface of the sterrasters of the ‘ Isops intuta ’ specimen from the Balgim expedition (Boury-Esnault et al., 1994, fig. 112e–f) was not typical of Caminella . The two tiny Balgim specimens (3 mm in diameter), dredged off Morocco at 1510 m, clearly have sterrasters with rosettes typical of Geodia species. Furthermore, we examined three slides (2 spicule preparations and 1 piece of cortex) from Balgim specimen CP63– 185. This specimen has i) slightly asymmetrical oxeas (versus symmetrical in C. intuta ), ii) shorter proto+deuteroclades, iii) presence of several anatriaenes and one protriaene (overlooked by the authors), but iv) we could not find the spherasters (although they are claimed to be present), instead we found v) smaller oxyasters (8– 12 versus 10–40 in C. intuta ) with a different morphology than in C. intuta (Boury-Esnault et al., 1994, fig. 112d), the oxyasters are more spiny, especially at the tip of the actins. To conclude, we are sure that the Balgim specimens have been misidentified and are a Geodia sp., probably a juvenile, which might explain the rarity of sterrasters in the cortex.

Figures

FIGURE 2. Caminella intuta (Topsent, 1892). A. Specimen in Gameau cave, La Ciotat, France (not collected), note the dark ring around uniporal oscules (large openings) and pores (small openings); B. Specimens in "lithistid cave", Chak El Hatab, Lebanon; C. Large specimen in Cosquer cave, France, field# PL617PC-7; D. ZMAPOR 21653 (after preservation in ethanol) from Carreiro Maldito cave, Berlengas, Portugal; E. Oscules (large) and pores (small) from specimen PL617PC-7, Cosquer cave (fixation in ethanol); F. Oscule and minute pores from specimen Sp175, Alboran Sea, 102-112 m depth (preserved in formalin, storage in ethanol).

FIGURE 3. A. NHMW-3Zoo-EV-MP345, slide of holotype of Caminella loricata Lendenfeld, 1894; B. NHMW-3Zoo-EV- MP346, slide of holotype of C. loricata. C. Section of holotype of C. loricata showing dichotriaenes, sterrasters and numerous oxyasters, scale: 100 µm (slide 345, picture: O. Macek); D. Section of holotype of C. loricata showing uniporal pores in the cortex of sterrasters, scale: 100 µm (slide 345, picture: O. Macek); E. close-up of picture D showing a uniporal pore filled with spherasters. Note the undeveloped status of the sterrasters, scale: 50 µm (slide 345, picture: O. Macek); F. Section of Caminella intuta (ZMAPOR 21653), from Carreiro Maldito cave, Berlengas, Portugal. Note the cloaca with oscule opening. G. Same section as in F, showing dichotriaenes, oxeas and sterrasters in the choanosome, as well as the thin cortex.

FIGURE 4. Caminella intuta (Topsent, 1892). A–B. Microscleres from specimen from Gameau cave, La Ciotat, France, 193S. A. Immature sterraster. B. Oxyasters and spherasters. C–D. Microscleres from specimen from the ‘Carreiro Maldito’ cave, 6-8 m, Berlengas, Portugal, ZMAPOR 21653. C. Young and immature sterrasters, oxyasters, spherasters (same scale as in A). D. Surface of immature sterraster with a spheraster.

FIGURE 5. Caminella intuta (TOpsENT, 1892), #13/07/2003-2 from “lithistid” cave, 2–3 m, Chak El Hatab, Lebanon. A. Mature sterraster, oxyasters and spherules. B. Spherules. C. Dichotriaene. Note the sterrasters at the tip of the rhabdome. D. Oxea (same scale as C).

FIGURE 6. Caminella intuta (Topsent, 1892). A–D. BMNH 1955.3.24.2 (=RMNH Por 647), paralectotype of Isops maculosus VOsmAER (1894), Gulf of Naples, 150–200 m. A. Mature sterrasters. B. Close-up of mature sterrasters on hilum. C. Oxyasters. D. Spherasters and spherules. E–G. field# Sp175, Alboran Sea, 102–112 m. E. Mature sterrasters (same scale as A). F. Spherasters (same scale as D). G. Oxyasters (same scale as C).

FIGURE 9. Caminella pustula sp. nov., MNHN-IP-2008-4, holotype. A. Sterrasters. B. Young sterraster. C. Surface of mature sterraster. D. Oxyasters. E. Spherules.