Antennella sp.

Agís, José Ansín, Vervoort, Willem & Ramil, Fran, 2009, Hydroids of the family Halopterididae (Cnidaria, Hydrozoa) collected in the western Pacific by various French expeditions, Zoosystema 31 (1), pp. 33-61 : 41-43

Antennella sp.

( Fig. 4 ; Table 5)

MATERIAL EXAMINED. — Norfolk Ridge. SMIB 4, stn DW 55, 23°21.4’- 23°21.4’S, 168°04.5’- 168°04.8’E, 215-260 m, 9.III.1989, 1 colony on sponge composed of several stems with 1 damaged gonotheca ( MNHN).

SMIB 5, stn DW 95, 22°59.7’S, 168°19.8’E, 200 m, 14.IX.1989, single stem without gonothecae ( MNHN).

DISTRIBUTION. — The colonies were collected at two localities of the Norfolk Ridge, between 200 and 260 m.

DESCRIPTION (COLONY FROM SMIB 4,

STN DW 55)

Hydrorhiza tubular, adhering to sponge; stems monosiphonic and unbranched.

A

Basal part of stem composed of three internodes separated by straight nodes; last internode with several nematothecae (maximum nine) arranged in two alternate longitudinal series and separated from remainder of stem by an oblique node. Rest of stem composed of a succession of hydrothecate and ahydrothecate internodes separated by alternating oblique and transverse nodes. Hydrothecate internode with oblique basal and distal straight node; reverse in ahydrothecate internodes.

Hydrothecate internodes with one hydrotheca and four nematothecae: one mesial inferior, two laterals and one axillar behind hydrotheca. Hydrothecae cup-shaped; abcauline wall straight or slightly concave in distal half; adcauline wall adnate for c. ⅓ its length and free portion concave; rim smooth.Mesial nematotheca reaching hydrothecal base, adcauline wall of upper chamber deeply scooped. Lateral nematothecae conical, placed on well-developed apophyses, one on each side of hydrotheca, reaching hydrothecal rim but not surpassing it. One axillar nematotheca behind hydrotheca, with wall of upper chamber lowered almost to bottom.

Ahydrothecate internodes with two or three nematothecae with adcauline wall of upper chamber lowered. All nematothecae are bithalamic and movable.

One damaged gonotheca, with two nematothecae on basal part, inserted below a hydrotheca on a short pedicel. The distal part is lost and it is therefore not possible to give a more detailed description.

VARIABILITY

The length of the mesial inferior nematotheca varies considerably, surpassing the hydrothecal base and reaching halfway the abcauline wall.

REMARKS

In morphology of the trophosome this material approaches Antennella secundaria ( Gmelin, 1791) , but it differs by the free portion of the adcauline wall that is concave, and by the varied length of the mesial inferior nematothecae that generally reach the hydrothecal base, although they can reach halfway the abcauline wall. Therefore we record this material as Antennella sp. and separate it from Antennella secundaria .

Figures

FIG. 4. — Antennella sp., SMIB 4, stn DW 55: A, internode from middle of hydrocladium, lateral view; B, internode with longer mesial infracalycine nematotheca, lateral view; C, internodes from middle of hydrocladium with three nematothecae on ahydrothecate internode, lateral view. Scale bar: 0.1 mm.