Farrea occa subsp. ouwensi Ijima 1927
| Main Authors: | Tabachnick, Konstantin R., Menschenina, Dorte Janussen And Larisa L. |
|---|---|
| Format: | info publication-taxonomictreatment Journal |
| Terbitan: |
, 2008
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/5133589 |
Daftar Isi:
- Farrea occa ouwensi Ijima, 1927 (Fig. 15, 16; Tab. 14) Material. Types: ZMA POR; POR 5101 – RV Siboga, sta 119. ZMA POR (two specimens) – RV Siboga, sta 122. ZMA POR; POR 3427 – RV Siboga, sta 124. ZMA POR– RV Siboga, sta 226. ZMA POR 5098 – RV Siboga, sta 252. New specimens: MNHN (fr875) (two specimens)— Cidaris I, RV Franklin, sta. 15 3, 17 o 45.49' S 148 o 37.52' E, depth 945 m. Description. Body: Both new specimens are small and tubular (probably juveniles). The bigger one is a 26 mm long tube, 3.5 mm in diameter in the lower part and 5 mm in diameter in the upper part, with basidictyonal remnants about 5 mm in diameter. The small specimen is 15 mm long, 2.5 mm in diameter in the lower part and 5 mm in diameter in the upper part. Framework: Dictyonal skeleton; typical farreoid skeleton, which consists 2–3 dictional layers. Skeletal beams are smooth or rarely rough 0.04–0.1 mm in diameter, distances between the spicules' centers are 0.2– 0.5 mm, the free meshes are rectangular or rarely triangular, 0.1–0.4 mm. The free rays, which protrude inside and outside the body wall, are short, 0.08–0.1/ 0.02 mm, usually rough with rounded outer ends. Some small hexactins are fixed to the dictyonal skeleton by one of their rays; these hexactins have rays of 0.01–0.03/ 0.002 –0.003 mm. In one of the type specimens, ZMA POR 5098, the beams are spined. Loose spicules: The variability of the loose spicules may be observed in Tab 14. It is worth noting that pentactins with spines outwardly directed seems to predominate among dermal pentactins, while the pentactins with rough rays are usually atrial spicules. The form of the heads of pileate clavules varies in the speciemens of the type series. Microscleres: The microscleres are discohexasters, oxyhexasters and rarely onychohexasters and their hemihexasterouse forms. Ijima (1927) described two the latter types as tylohexasters. Oxyhexasters were not found in one type species from sta. 122. Remarks. The subspecies looks to be very polymorphic even in the type series. The original description of Ijima (1927) is not satisfactory and we supplement it here by new data given above, the spicule measures are defined more precisely in Tab. 14. The new material perfectly goes within the type series variation.
- Published as part of Tabachnick, Konstantin R. & Menschenina, Dorte Janussen And Larisa L., 2008, New Australian Hexactinellida (Porifera) with a revision of Euplectella aspergillum *, pp. 7-68 in Zootaxa 1866 (1) on pages 36-37, DOI: 10.11646/zootaxa.1866.1.3, http://zenodo.org/record/5133305