Aglaophenia howensis Briggs, 1918

Galea, Horia R., 2020, Aglaopheniid hydroids (Cnidaria: Hydrozoa: Aglaopheniidae) from off New Caledonia collected during KANACONO and KANADEEP expeditions of the French Tropical Deep-Sea Benthos Program, European Journal of Taxonomy 615, pp. 1-47 : 2-3

Aglaophenia howensis Briggs, 1918

Figs 1 A–B, 2

Halicornaria sp. nov. Whitelegge, 1899a: 41.

Aglaophenia howensis Briggs, 1918: 27 , pl. 5 figs 1–2, pl. 6 fig. 1.

Lytocarpia howensis – Vervoort & Watson 2003: 311, fig. 75a–d.

Material examined

PACIFIC OCEAN • 3 plumes without hydrorhizae, 5 cm, 10 cm and 10 cm, respectively, the latter bearing gonothecae; off New Caledonia, stn CP4786 ; 22°46ʹ S, 167°42ʹ E; 350–469 m; 29 Aug. 2016; KANACONO leg.; MNHN-IK-2015-544 .

Remarks

For a thorough description of this species, refer to Briggs (1918). Vervoort & Watson (2003) removed it from Aglaophenia Lamouroux, 1816 and placed it in Lytocarpia Kirchenpauer, 1872 , on the account of peculiarities of its hydrothecae, not taking into account the morphology of its gonosome, otherwise well documented in the original account. The species was then transferred back to Aglaophenia after the examination of the present material with corbulae, whose structure does not include hydrothecae at the base of the costae ( Fig. 1B ).

As noted by Briggs (1918), a reversal of the orientation of cladia, whose hydrothecae face either the frontal (F) or dorsal (D) aspect of the cormoid, could be noted. In the fertile plume available, this change occurs 12 times, as follows (from proximal to distal end): 15 (F), 10 (D), 7 (F), 12 (D), 19 (F), 10 (D), 8 (F), 13 (D), 34 (F), 26 (D), 29 (F), 32 (D), and 13 (F), the numbers representing the number of consecutive cladia per side of cormoid and per group of orientation. Implicitly, when corbulae are present within a given group, their orientation with respect to the side of the plume changes as well.

Distribution

Scattered records from the Tasman Sea area, up to Norfolk Island in the North ( Vervoort & Watson 2003); New Caledonia (present report).

Figures

Fig. 1. A–B. Aglaophenia howensis Briggs, 1918, fertile cormoid (A) and corbula (B), both from sample MNHN-IK-2015-544. — C. Aglaophenia sinuosa Bale, 1888, cormoid from sample MNHN- IK-2015-545. — D–E. Cladocarpus asymmetricus sp. nov., fertile cormoid (D) and phylactocarp (E) from sample MNHN-IK-2015-530 (holotype). — F. Cladocarpus keiensis Schuchert, 2003, colony from sample MNHN-IK-2015-534. Scale bars: F = 2 cm; A, C–D = 1 cm; E = 1 mm; B = 500 µm.