Mycale (Aegogropila) tunicata ( Schmidt, 1862 )

Gugel, Jochen, Pfannkuchen, Martin & Brümmer, Franz, 2006, Redescription of Mycale tunicata (Schmidt, 1862) (Porifera, Demospongiae, Poecilosclerida) from Rovinj, Croatia, northern Adriatic Sea, Zootaxa 1191 (1191), pp. 21-34 : 24-26

Mycale (Aegogropila) tunicata ( Schmidt, 1862)

Esperia tunicata Schmidt, 1862, p. 55 , plate V, Fig. 4

Esperia bowerbankii Schmidt, 1862, p. 55

Esperia nodosa Schmidt, 1864, p. 33 . plate III, Fig. 10

? Esperia tuberosa Schmidt, 1868 (?), p. 26

Material examined

Two specimens were dregded in the bay of Rovinj by F. Brümmer (30.08.2002: ZMA POR 18991, 10.09.2003: ZMA POR 18992), five specimens collected during SCUBAdiving by F. Brümmer & M. Pfannkuchen (30.08.2004: ZMA POR 18993–18997 ) .

Comparative material

ZMA:

Mycale (Aegogropila) contareni (Martens, 1824) (ZMA Por. 09695, ZMA Por. 00266)

Mycale (Aegogropila) rotalis (Bowerbank, 1874) (ZMA Por. 04184, ZMA Por. 13361)

Mycale (Aegogropila) syrinx ( Schmidt, 1862) (ZMA Por. 02438, ZMA Por. 00815,

ZMA Por. 06044)

Mycale (Aegogropila) tunicata ( Schmidt, 1862) (ZMA Por. 15355)

Mycale (Carmia) macilenta (Bowerbank, 1866) (ZMA Por. 14135, ZMA Por. 14142)

Mycale (Carmia) minima (Waller, 1881) (ZMA Por. 04833, ZMA Por. 04833)

Mycale (Carmia) similaris (Bowerbank, 1874) (ZMA Por. 04186, ZMA Por. 13351)

Mycale (Mycale) lingua (Bowerbank, 1866) (ZMA Por. 16791, ZMA Por. 16792,

ZMA Por. 04978), ZMA Por. 04979)

Mycale (Mycale) massa ( Schmidt, 1862) (ZMA Por. 01603, ZMA Por. 15059)

RMNH:

Mycale tunicata ( Schmidt, 1862) ( RMNH 209 )

LMJG:

Esperia tunicata Schmidt, 1862 ( LMJG 15380 : 9 fragments, LMJG 15381 : 23

fragments + the lectotype ( LMJG 15381 /1))

External morphology

Color of life specimens yellowish ( Fig. 1), turning to gray after fixation in 70% Ethanol. The specimen (ZMA POR 18992, on this specimen most of the description and all measurements are based) consists of a massive base, with several irregular digitate processes. Some of these processes are fused again, the whole appearance is very irregular, reaching a height of about 15cm.

Surface optically smooth, in parts slightly conulose with low, irregular conules ( Fig. 1). A number of freshly collected specimens with conspicuous bright yellow spots ( Fig. 1b, Fig. 2a). Skeletal tracts might pierce the surface, single spicules rarely projected beyond the surface.

Surface sometimes torn, especially near the origin of the processes, probably following the very abundant subectosomal channels.

No oscules were seen on the fixed sponge, some living specimens in situ with round, small oscules (1–2mm in diameter, slightly raised) on the digitate processes. They disappeared after collection and did not reappear in the aquarium.

Consistency soft, not elastic and easy to cut or tear.

Skeleton

Ectosome easily detachable in small pieces and visible in close­ups of the surface ( Fig. 2a). Ectosomal skeleton formed by a regular anisotropic reticulation of tracts of megascleres ( Fig. 2a, b, meshes about 300µm in diameter). Primary tracts (20–40µm) multi­ to paucispicular, connected by uni­ to paucispicular secondaries (15–25µm).

Choanosomal skeleton ( Fig. 2c) irregular and plumose to plumoreticulate, consisted mainly of ascending robust tracts (ca. 100µm thick), clearly defined secondaries often lacking. Here many interstitial spicules could be seen.

Anisochelae 3 often built rosettes ( Fig. 2e, f). Rosettes were not present in all specimens, but in specimens where they occurred, they were frequently observed. The rosettes were built by 6 – 8 – 10 anisochelae. All microscleres were distributed in the whole sponge body between the tracts built by the megascleres.

Parts of the sponge were covered by sediment (mainly lower parts of the sponge), the skeleton remained here intact but dead ( Fig. 1b, c, d, 2d). These parts of the sponge remained in the sediment and could not be seen in situ.

The dead skeleton ( Fig. 2d) was built up by the choanosomal skeleton, no microscleres or interstitial spicules. Secondary tracts completely lacking, primary tracts anastomosing. The reticulation is irregular, elongate meshes of up to 1mm long and only several 100µm wide, tracts about 100µm thick, at crossing points up to 300µm.

Generally no foreign material, except in the dead skeleton, with many sand grains ( Fig. 2d).

Spicules

Megascleres subtylostyles to styles ( Fig. 3a, sometimes referred to as mycalostyles), straight or slightly bent, rarely flexuous ( Fig. 3b) or irregular bent. Tyle only a slight swelling ( Fig. 3a), Measurements can be found in Tab. 1.

Microscleres palmate anisochelae of three types and Trichodragmata, all abundant in the whole sponge body, measurements are included in Tab. 1.

Anisochelae 1: ( Fig. 3c).

Anisochelae 2: ( Fig. 3d, rather rare).

Anisochelae 3: ( Fig. 3e).

Trichodragmata ( Fig. 3f): bundles of very thin raphides ( Fig. 3c, d), hardly visible in spicule preparations.

Ecology

The samples originated from a depth of 25–26m in the bay of Rovinj, Croatia, northern Adriatic Sea. The species occurs on soft substratum along with large specimens of other sponges like Ulosa stuposa (Esper, 1794) and Tedania anhelans (Lieberkühn, 1859) . The habitat was characterized by strong currents (about 15m /min). The sponges served as islands of settlement for several other species (e.g. Ophiuridea, Polychaeta, Holothuroidea). The adhering dead skeleton was a mean of anchoring the sponge in the soft substratum.