Litophyton obtusum Van 2020
- Dataset
- The genus Litophyton Forskål, 1775 (Octocorallia: Alcyonacea: Nephtheidae) from Australia
- Rank
- SPECIES
- Published in
- Van Ofwegen, Leen P. (2020): The genus Litophyton Forskål, 1775 (Octocorallia: Alcyonacea: Nephtheidae) from Australia. Zootaxa 4764 (1): 1-131, DOI: 10.11646/zootaxa.4764.1.1
Classification
- kingdom
- Animalia
- phylum
- Cnidaria
- class
- Anthozoa
- order
- Alcyonacea
- family
- Nephtheidae
- genus
- Litophyton
- species
- Litophyton obtusum
description
(Figs. 31 c, 32 c, 36)
description
Description. The NTM C 4164 holotype is 10.5 cm high and 10 cm wide, the stalk is 1 cm long (Fig. 31 c). The polyps are up to 0.7 mm wide and 0.9 mm high, mostly situated on long catkins. Polyps. With a relatively regular arrangement of sclerites in points (Fig. 32 c). Abaxial and lateral point sclerites are spindles with spines, the largest present abaxially, up to 0.50 mm long, laterally they are up to 0.25 mm long (Fig. 36 a). Adaxially there are no sclerites, only the tentacles have sclerites in this part of the polyp, small, bent rods, up to 0.10 mm long (Fig. 36 b-c). Supporting bundle very weak and not projecting, composed of spindles, up to 1 mm long, with simple tubercles, more tuberculate at both ends (Fig. 36 d). Surface layer top stalk. Spindles and unilaterally spinose spindles, up to 0.80 mm long, with simple and complex tubercles (Fig. 36 e). Surface layer base stalk. Capstans and derivatives of capstans (Fig. 36 f-g), 0.05 - 0.20 mm long. Spindles and unilaterally spinose spindles are also present, up to 0.50 mm long, with simple and complex tubercles. The spines of the unilaterally spinose sclerites are very long. Interior stalk. Spindles, up to 1 mm long (Fig. 36 h), with pointed or blunt ends and quite tall complex tubercles (Fig. 36 j). The smaller spindles are less tuberculate (Fig. 36 i). Variability. The length of the basal internal stalk spindles does vary, NTM C 4377 has the longest, up to 1.80 mm long. Several specimens have rods in the polyp stalk, sometimes in larger numbers than present in L. acutum sp. nov.
discussion
Remarks. L. acutum sp. nov., L. obtusum sp. nov., and L. territoryensis sp. nov. all have unilaterally spinose sclerites with long spines. The differences are discussed with L. acutum. The permanent microscope slide of NTM C 4356 did not show the characteristic internal spindles of this species, an additional temporary slide did show them. The species resembles L. capnelliformis (Thomson & Dean, 1931), from Timor, Indonesia, regarding the internal stalk spindles with blunt ends (Fig. 82 g). However, L. capnelliformis lacks the unilaterally spinose sclerites in the polyps and in the surface of the stalk. Unfortunately, the polyp sclerite arrangement of L. capnelliformis is not clear due to a large amount of detritus present in the polyps. Therefore, the one polyp drawn (Fig. 82 a) could have rods in the adaxial side of the polyp stalk, as others do, the rods are possibly just hidden by the detritus.
distribution
Distribution. Great Barrier Reef: Brewer reef, Davies reef, Rib reef, Myrmidon reef, Dip reef.
etymology
Etymology. From the Latin obtusus, blunt, refers to the presence of interior stalk spindles with blunt ends.
materials_examined
Material examined. Holotype NTM C 4164, Queensland, Great Barrier Reef, Brewer reef, reef flat, 8 February 1981, coll. Z. Dinesen; paratypes: NTM C 4035; Queensland, Great Barrier Reef, Davies reef, depth 5 - 10 m, 16 April 1981, coll. Z. Dinesen; NTM C 4134, Queensland, Great Barrier Reef, Myrmidon reef, depth 10 - 15 m; 23 November 1980, coll. Z. Dinesen; NTM C 4137, Queensland, Great Barrier Reef, Davies reef, depth 10 - 15 m, 16 April 1981, coll. Z. Dinesen; NTM C 4138, Queensland, Great Barrier Reef, Dip reef, depth 15 - 20 m, 5 February 1981, coll. Z. Dinesen; NTM C 4155, Queensland, Great Barrier Reef, Davies reef, depth 1 - 5 m, 16 April 1981, coll. Z. Dinesen; NTM C 4237, Queensland, Great Barrier Reef, Flinders reef, depth 1 - 5 m, 20 November 1981, coll. Z. Dinesen; NTM C 4327; Queensland, Great Barrier Reef, Rib reef, depth 10 m, 5 October 1980, coll. Z. Dinesen; NTM C 4356, Queensland, Great Barrier Reef, Myrmidon reef, depth 10 - 15 m, 3 February 1981, coll. Z. Dinesen; NTM C 4365; Queensland, Great Barrier Reef, John Brewer reef, depth 10 - 15 m; 7 February 1981, coll. Z. Dinesen; NTM C 4373, Queensland, Great Barrier Reef, Myrmidon reef, depth 1 - 5 m, 3 February 1981, coll. Z. Dinesen; NTM C 4375; Queensland, Great Barrier Reef, Dip reef, depth 10 - 15 m, 5 February 1981, coll. Z. Dinesen; NTM C 4377, Queensland, Great Barrier Reef, Dip reef, depth 15 - 20 m, 5 February 1981, coll. Z. Dinesen; NTM C 4394, Queensland, Great Barrier Reef, Dip reef, depth 5 - 10 m, 9 October 1981, coll. Z. Dinesen; NTM C 5391, Queensland, Great Barrier Reef, Darley reef, 25 November 1982, coll. G. König.
Name
- Homonyms
- Litophyton obtusum Van 2020