Geodia papyracea ( Hechtel, 1965 )

Cárdenas, Paco, Menegola, Carla, Rapp, Hans Tore & Díaz, Maria Cristina, 2009, Morphological description and DNA barcodes of shallow-water Tetractinellida (Porifera: Demospongiae) from Bocas del Toro, Panama, with description of a new species, Zootaxa 2276, pp. 1-39 : 32-34

Geodia papyracea ( Hechtel, 1965)

( Figure 16 )

Synonyms.

Geodia (Cydonium) papyracea Hechtel, 1965: 71 , text-fig. 13, pl. VIII, figs.1–2. Geodia papyracea Hechtel, 1965 : Alcolado 1981, p. 38.

Holotype. YPM 5045, mangrove boat channel, Port Royal, Jamaica.

Material. UMPCW 921, Solarte Island, on a mangrove root, 0.5–1 m depth.

Additional material examined. G. papyracea , YPM 5045, holotype, mangrove boat channel, Port Royal, Jamaica; YPM 5309, 5311, paratypes, mangrove boat channel, Port Royal, Jamaica; USNM 42662, mangrove, Twin Cays, Belize.

Outer morphology ( Fig. 16 A). Whitish massive sponge with green tinges when alive. It is ca 6x 12 cm. The sub-sample we have is whitish in alcohol; the cortex being lighter than the choanosome. Oscules are uniporal, each with a sphincter and grouped in a sub–circular, slightly depressed plate. The oscule plate can be dark green. Pores are cribriporal and widely distributed over the entire surface. Each cribriporal plate has a diameter of 1 mm.

Skeleton ( Fig. 16 B). The cortex is 480–840 µm thick and composed of a thin ectocortex of strongylasters (0–72 µm) and a thicker endocortex made of sterrasters (480–840 µm). The cortex is easily torn and detachable from the choanosome. Oxeas I and plagiotriaenes are positioned under the cortex, more or less radially. The plagiotrianes usually cross the cortex so that the cladomes end up in the ectocortex or at the surface of the cortex. The radial arrangement of megascleres is less obvious 1 mm under the cortex. Oxyasters I, oxyasters II and strongylasters can be found in the whole choanosome, as well as developing sterrasters. Oxeas II, smaller than oxeas I, are only found in the choanosome.

Spicules ( Fig. 16 C–G). Megascleres: (a) oxeas I, stout, straight or slightly bent, length: 651– 1039 –1248 µm; width: 7– 24.3 –29 µm. (b) oxeas II, rare, sometimes with strongyle ends, usually straight, length: 95– 124.3 –244 µm; width: 1– 2 –3 µm (N=14). (c) plagiotriaenes, rhabdome length: 641– 962.7 –1080; rhabdome width: 13– 24.6 –34 µm; clad length: 57– 97.1 –132 µm. (d) anatriaenes, rare, rhabdome length: 354– 633.2 –885 µm (N=5); rhabdome width: 2.5– 3.2 –4 µm (N=8); clad length: 5– 13.8 –27 µm (N=8). (e) mesoprotriaenes, very rare, rhabdome length: 632 µm (N=1); rhabdome width: 3 µm (N=1); clad length: 9–16 µm (N=2).

Microscleres: (f) sterrasters ( Fig. 16 C–D), subglobular, with warty 4–7 branched rosettes at their surface (diameter: ca 4 µm), length: 65– 71.6 –77 µm; width: 63– 70.3 –75 µm; thickness: 50– 55.9 –61 µm. (g) acanthoxyasters I ( Fig. 16 E), 9–12 thin actines, center more or less developed, diameter: 22– 27.5 –36 µm. (h) acanthoxyasters II ( Fig. 16 F), with large centrum and thicker actines than acanthoxyasters I, 9–17 actines, less common than acanthoxyasters I. diameter: 14– 23 –29 µm. (i) acanthostrongylasters ( Fig. 16 G), 14–20 actines, diameter: 3– 4.9 –8.8 µm.

Habitat in the Bocas del Toro region. On mangrove roots, 0.5–1.5 m depth.

Distribution. Cuba ( Alcolado 2002); Belize ( Rützler 1988; Rützler et al. 2000); Panama (Díaz 2005); Jamaica ( Hechtel 1965); Colombia ( Wintermann-Kilian & Kilian 1984); Curaçao (van Soest 1981); Brazil ( Burton 1940; da Silva et al. 2004; Cedro et al. 2007).

Remarks and discussion. The fragile and easily peeled cortex of G. papyracea might be due to the peculiar disposition of the triaenes, with the cladomes not supporting the cortex as in most Geodia species. The ectocortex of the Bocas del Toro specimen was much thinner (0–72 µm) than in the Belize sample (120–325 µm) and the holotype / paratypes (93–232 µm thick). Conversely, the sterrastreal layer in the Bocas del Toro specimens was thicker (480–840 µm) than in the Belize sample (93–279 µm) and the holotype / paratypes (186–418 µm). This is partly a consequence of the larger sterrasters in comparison with the type material and previous G. papyracea records (da Silva et al. 2004). We also noted that the surface of the Bocas del Toro specimen was less folded, the parchment–like appearance characteristic of this species was therefore not as obvious as in the samples from Jamaica and Belize. The rest of our measurements were in accordance with the species description. This species was very common in Solarte lagoon in 2005 and 2006 (M. C. Díaz, personal observation). We were not able to find it anymore in 2007 and 2008 as it appeared to have been replaced by the sympatric species Geodia gibberosa .

In the field, G. papyracea can be mistaken with the previously described G. gibberosa since they are both found living on mangrove roots and can even be found growing on one another ( Hechtel 1965). Again, gross morphology is here important: G. papyracea has very poor relief and a fragile cortex while G. gibberosa has characteristic lobes and a tough and thicker cortex. G. gibberosa seems to be more overgrown than G. papyracea . In thick sections, the skeleton was more radially organized in G. gibberosa ( Fig. 14 E), with plagiotriaenes supporting the cortex and not crossing it like in G. papyracea ( Fig. 16 B). This probably accounts for the firm cortex in the former. Then, G. gibberosa has larger oxeas and plagiotriaenes; the sterrasters are also a bit larger and more oval shaped. SEM pictures of asters revealed additional microstructural differences. When comparing the surface of sterrasters, the G. gibberosa rosettes ( Fig. 15 D) had less rays than those of G. papyracea ( Fig. 16 D). In G. gibberosa , rosettes also had a smaller center and no warts on the rays. Seemingly, the hilum of the sterrasters were different (the hilum is a circular depression, a remnant of where the nucleus of the sclerocyte used to be): smooth in G. gibberosa , warty in G. papyracea . These differences were confirmed by SEM observation of the holotypes’ sterrasters ( Figs. 15 H, 16H). We also noticed that the actines of the acanthoxyasters III in G. gibberosa ( Fig. 15 G) have a more prominent spine at their tip when compared with the acanthostrongylasters of G. papyracea ( Fig. 16 G). Finally, these two species had significantly different Folmer COI sequences (60 bp. difference) and 28S partial sequence (63 bp. difference). A molecular phylogenetic study shows that they belong to two clearly seperated Geodia clades ( Cárdenas et al. 2009).

Although the holotype (YPM 5045) has been fixed and preserved in alcohol, the DNA we extracted from it was poorly preserved. Consequently, we were unable to amplify the Folmer COI fragment or a 28S sequence from the type material.

Figures

FIGURE 14. Geodia gibberosa Lamarck, 1815: A. Large specimen hanging at the tip of a mangrove root. It is overgrown by the purple sponge Chalinula molibta, algae and oysters. Scale: 6 cm; B. Specimen with characteristic tumulose shape; C. Close up of oscular plates of an overgrown specimen in situ. Each oscule is uniporal. Scale: 4 cm; G. gibberosa: [ZMBN 81780]: D. Close up of the cribriporal pores. Scale: 1 mm; E. Cross – section showing the skeletal architecture: cortex and choanosome. Note the radial arrangement of the triaenes right under the cortex. Scale: 1 mm; F. Cross – section of a uniporal oscule. mx: cortical microxeas. s: sphincter. plgt: plagiotriaene. Scale: 0.5 mm.

FIGURE 15. Geodia gibberosa Lamarck, 1815 [ZMBN 81780]: A. Plagiotriaene and sterrasters. Scale: 200 µm; B. Anatriaene cladome. Scale: 20 µm; C. Sterraster. Scale: 20 µm; D. Star – shaped smooth rosettes and hilum from a sterraster surface. Scale: 4 µm; E. Acanthoxyaster I. Scale: 4 µm; F. Acanthoxyaster II. Scale: 2 µm; G. Acanthoxyasters III. Scale: 2 µm; G. gibberosa [MNHN DT – 608, holotype]: H. Smooth rosettes and hilum from a sterraster surface. Scale: 4 µm.

FIGURE 16. Geodia papyracea (Hechtel, 1965) [UMPCW 921]: A. Specimen in situ, growing on a mangrove root, arrow points to the oscule plate with uniporal oscules (Picture: Scott Nichols). Scale: 3 cm; B. Cross – section showing the skeletal architecture: cortex and choanosome. Note the confused arrangement of the megascleres in the choanosome. Scale: 1 mm; C. Sterraster, with an acanthostrongylaster by the warty hilum. Scale: 20 µm; D. Star – shaped warty rosettes from a sterraster surface. Scale: 4 µm; E. Acanthoxyaster I and acanthostrongylasters. Scale: 4 µm; F. Acanthoxyaster II. Scale: 4 µm; G. Acanthostrongylasters. Scale: 2 µm; G. papyracea [YPM 5045, holotype]: H. Warty rosettes and hilum from a sterraster surface. Scale: 4 µm.