Dictyoceratida Minchin 1900

South Pacific Ocean, Duration 10 seconds

South Pacific Ocean, Duration 10 seconds

Hippospongia canaliculata, var. gossypina.

Hippospongia equina, var. meandriformis.

Hircinia campana.

Figure 11Dysidea tupha. a specimen with typical cylindrical processes and finely, irregularly conulose surface; b, c views of the skeleton with fibres variably charged of mineral detritus (LM).

Euspongia officinalis, var. tuba.

Hippospongia equina, var. elastica.

Figure 12Euryspongia raouchensis. a underwater image of a living specimen b small conules (thin section by LM) with slightly protruding fibres at the sponge surface and skeletal network with cored ascending primaries and uncored secondaries. a, b modified from Vacelet et al. (2007).

Euspongia officinalis.

Figure 13Pleraplysilla minchini. a encrusting specimens in a small facies (Mitigliano Cave) b detail of dendritic skeleton fibres with debris filling the axial core.

Euspongia officinalis, var. adriatica.

Figure 14Pleraplysilla spinifera. a large specimen (ca. 5 cm) b ramified, cored dendritic fibres (LM).

Figure 15Ircinia dendroides. a specimen with typical cylindrical ramifications b details of the skeletal network with cored primary fibres, uncored secondaries forming large cribrose plates, and filaments with the typical apical knob. a modified from Pulitzer-Finali and Pronzato (1980) b modified from Rubió-Lois et al. (1981).

Figure 16Ircinia oros. a specimen with an epibiotic haliclonid (lightest area) b magnifications (LM) of typical irciniid skeletal filaments c schematic drawings of cored primary fibres, uncored secondary network and a filament with the terminal knob. c modified from Rubió-Lois et al. (1981).

Figure 17Ircinia paucifilamentosa. Peculiar shape of the terminal knobs of filaments in the only available illustration for this species. Modified from Vacelet (1961).

Figure 18Ircinia retidermata. a habitus of the type specimen b an underwater image of a living specimen c, d, e different magnifications (LM) of the skeletal network showing cored primary fibres, uncored secondaries, and the typical irciniid filaments f sponge surface finely granulate by mineral debris embedded in a very close fibrillar network. a modified from Pulitzer-Finali and Pronzato (1980).

Figure 19Ircinia variabilis. a–c wide array of growth forms in different specimen d skeletal spongin network of primary and secondary fibres, and filaments (LM) e skeletal spongin network of primary and secondary fibres, and filaments (SEM) f magnification of a filament at the terminal knob; g, h regularly and finely sandy sponge surface. d) modified from Pronzato et al. (2004).

Figure 20Sarcotragus fasciculatus. a living specimen (ca. 7 cm) b type specimen 15499 of the Schmidt’s collection preserved in the Landes Museum Joanneum of Graz c skeletal network without inclusions in primary fibres (detail of b). b, c modified from Pronzato et al. (2004).

Figure 21Sarcotragus foetidus. a a large (ca. 40 cm) living specimen free of epibiotic organisms b magnification of the sponge surface network c large specimen (ca. 35 cm) with dense epibiotic organisms d uncored skeleton fibre e very thin filaments.

Figure 22Sarcotragus pipetta. a living specimen in the Mitigliano Cave b type specimen 15495 from the Algerian coasts of the Schmidt’s collection in the Landes Museum Joanneum of Graz c skeletal network close to the sponge surface (LM) with ascending primary fibres supporting conules and filaments.

Figure 23Sarcotragus spinosulus. a, b specimens with different growth form c–g different magnifications of skeletal network with primary and secondary fibres, and filaments (LM and SEM).

Figure 24Coscinoderma sporadense. a type specimen b, c network architecture of almost transparent secondary fibres d connections between primary and secondary fibres e primary fibre completely cored by inclusions f close-up of the sponge’s surface engulfing mineral grains and spicules. a–f modified from Voultsiadou-Koukoura et al. (1991).

Figure 25Hippospongia communis. a a large, over 25 cm, specimen collected along the Libyan coast b, c skeletal network with tips of primary cored fibres supporting conules at the sponge surface d ascending tracts of primary fibres in the choanosome.