A guide to the deep-water sponges of - NMFS Scientific Publications ...
Share Embed Flag
Download ePaper

A guide to the deep-water sponges of - NMFS Scientific Publications ...

A guide to the deep-water sponges of - NMFS Scientific Publications ... A guide to the deep-water sponges of - NMFS Scientific Publications ...

spo.nmfs.noaa.gov
from spo.nmfs.noaa.gov More from this publisher
19.02.2013 Views

24 Professional Paper NMFS 12 10. Heterochone calyx calyx Schulze, 1886 (continued)

11. Regadrella okinoseana Ijima, 1896 Description. This tube or sac sponge attaches basally to hard substrate. Lateral walls bear distinctive smooth depressions, each with a small (1–3 mm diameter) central hole (parietal osculum) connecting to the atrial cavity; edges around depressions often project several millimeters as parietal ledges; the large terminal osculum is normally covered by a coarse sieve plate and bordered by a flaring marginal cuff. Consistency is slightly compressible and rubbery. The partially collected Alaskan specimen lacked an oscular sieve plate, marginal cuff, and parietal ledges. Its atrial cavity was subdivided by longitudinal wall fusions. It is estimated to have been 25 cm long by 13 cm diameter, but elsewhere incomplete specimens 48 cm long have been reported. Color in life is white; drab when dried or preserved in ethanol. Skeletal structure. While the Aleutian specimen may have unusual morphology, its spiculation is typical for the species. Its skeleton consists mainly of loose spicules; spicule fusion is present only in the lower parts collected and is assumed to have been extensive in the basal part left on the attachment site. Megascleres include thick principal diactins with rounded tips (5–16 mm long); thin diactins with pointed tips (1.3–7.5 mm long); sword-shaped dermal hexactins with short, tapered, pointed distal rays (89–369 µm length), tapered and pointed tangential rays (156–318 µm length), and long tapered proximal rays (232–807 µm length); regular hexactins (134–292 µm ray length); atrial pentactins with sharp tapered tangential rays (122–295 µm ray length) and longer proximal rays (137–563 µm ray length); a few atrial triactins and stauractins of similar shape and size; short, thick atrial diactins (347–1047 µm length); small diactins around parietal oscula (42–197 µm length). Microscleres include mainly oxystaurasters (61–107 µm diameter); a few oxyhexasters (70–129 µm diameter); dermal floricomes (78–113 µm diameter) with 10–14 terminal rays ending in heads with 2–3 teeth; remnants of graphiocomes are common, with central (25–43 µm diameter) and terminal rays as dispersed thin raphides (141–237 µm long). Zoogeographic distribution. Widespread but uncommon. In Alaska – central Aleutian Islands. Elsewhere – reported from Indo-West Pacific Region including from near India, Northwest and South Australia, New Zealand, New Caledonia, Indonesia, Japan. 25 Habitat. In Alaska – occurs singly on mudstone, bedrock, and possibly hexactinellid skeletons at depths between 1071 and 1395 m. Elsewhere – reported at depths between 390 and 1264 m. Remarks. The new record of this species in the Aleutian Islands represents a range extension of over 3700 km from the nearest previous known site near Japan. Photos. 1) Fragment of preserved (frozen) specimen collected at a depth of 1386 m in the central Aleutian Islands. Grid marks are 1 cm 2 . 2) Same specimen as in photo 1 in situ. The separation between the red laser marks is 10 cm.

24 Pr<strong>of</strong>essional Paper <strong>NMFS</strong> 12<br />

10. Heterochone calyx calyx Schulze, 1886 (continued)

logo

products

Resources

Company

Terms of service
Privacy policy
Cookie policy
Cookie settings
Imprint
Change language
Made with love in Switzerland
© 2024 Yumpu.com all rights reserved

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!