Ecionemia Bowerbank

Kelly, Michelle & Sim-Smith, Carina, 2012, A review of Ancorina, Stryphnus, and Ecionemia (Demospongiae, Astrophorida, Ancorinidae), with descriptions of new species from New Zealand waters, Zootaxa 3480, pp. 1-47 : 13-14

Genus Ecionemia Bowerbank

Ecionemia Bowerbank, 1862: 1101 .

Stellettinopsis Carter, 1897: 348 (in part).

Type species: Ecionemia acervus Bowerbank, 1864: 173 .

Diagnosis. Massive or thickly encrusting Ancorinidae with a thin, indistinct non-detachable ectosome defined by pigmented cells and aquiferous canals. Megascleres include oxeas in several size categories, and triaenes of different types including dichotriaenes, plagiotriaenes, anatriaenes, and protriaenes. Bundles of megascleres radiate strictly in the outer choanosome, expanding into brushes at the surface, and extending beyond. Microscleres include small euasters, and acanthomicrorhabds which form a dermal crust (emended from Uriz 2002).

Remarks. The type species Ecionemia acervus was first described from Fiji and has a wide distribution throughout the Indo-Pacific. The megascleres are large oxeas (>1000 um), orthotriaenes, and anatriaenes. The microscleres are acanthomicrorhabds, chiasters, and tylasters. In her diagnosis of the genus, Uriz (2002) states that the euasters of Ecionemia are never oxyasters, but E. densa has oxyasters in the smallest euaster category (see Table 3). It appears that species of Ecionemia never have the larger category of oxyasters that are found in the choanosome of Ancorina spp. and Stryphnus spp. Note also, that the euasters in New Zealand species of Ecionemia have recurved tips (see Fig. 5 D, I).

Figures

FIGURE 5. Megascleres and microscleres of New Zealand species of Ecionemia: Ecionemia alata, NIWA 52981: A. plagiotriaene, scale = 500 µm; B – C. anatriaenes, scale = 100 µm; D. chiaster with recurved spines, scale = 5 µm; E. acanthomicrorhabd, scale = 5 µm. Ecionemia novaezealandiae, NIWA 62156: F. plagiotriaene, scale = 500 µm; G. anatriaene, scale = 100 µm; H. promesotriaene, scale = 100 µm; I. chiaster with recurved spines, scale = 5 µm; J. spherochiaster, scale = 5 µm; K. acanthomicrorhabd, scale = 5 µm.