Acryptolaria angulata (Bale, 1914)

Watson, Jeanette E., 2019, Bathyal and abyssal hydroids (Hydrozoa, Leptothecata) from southeastern Australia, Memoirs of Museum Victoria 78, pp. 65-72 : 65-66

Acryptolaria angulata (Bale, 1914)

Figure 1 a, b

Cryptolaria angulata Bale, 1914: 166 , pl. 35, fig. 1.− Bale, 1915: 251.− Stranks 1993: 7.

Acryptolaria angulata .− Blackburn 1942: 111.− Vervoort and Watson 2003: 41 (synonymy).

Record. QM G337451 , microslide. Coll: off Fraser Island , Queensland, 25.3253 S, 154.0683 E to 25.3513 S, 154.076 E, 2350– 2342 m, beam trawl, 11/06/2017 .

Description. A small infertile colony 30 mm long with remnant hydrorhizal stolons. Stem fascicled, polysiphonic tubes thin, irregularly parallel, of same diameter as stolon.

Hydrothecae given off all around stem, tubular, a sharp outward bend in hydrotheca at junction of abcauline wall with stem; some hydrothecae widening almost imperceptibly to margin. Margin circular, everted, rim minutely outrolled; margin usually with many replications.

Perisarc throughout (preserved material) thin and lax.

Remarks. The strengthening buttresses reported in Acryptolaria angulata by Vervoort and Watson (2003) are actually abcauline intrathecal septa; these do not occur in the present specimen. Septae probably develop to strengthen the hydrotheca in strong water movement, not encountered by specimens in quieter deep-water conditions. The marginal replications of the hydrothecae considerably extends their length.

Distribution. A widespread deep-water species recorded from the Indian Ocean, New Caledonia and rarely, New Zealand. The deepest previous record for the species is 913 m at the Kermadec Ridge.