Aglaophenia postdentata Billard, 1913

Galea, Horia R., 2013, New additions to the shallow-water hydroids (Cnidaria: Hydrozoa) of the French Lesser Antilles: Martinique, Zootaxa 3686 (1), pp. 1-50 : 34-35

Aglaophenia postdentata Billard, 1913

( Fig. 8 I–N)

Material examined. Stn. 14, 20.ii.2012, 1 m, M233: numerous plumes, some fertile (female) on Dyctiota sp. (MHNG-INVE-82877).

Remarks. Sterile material of this species was reported for the first time from the Caribbean in an earlier account on the hydroids of Guadeloupe ( Galea 2010a). The present specimens from Martinique are fertile and confirm the previous identification. It is interesting to note some minor differences, as for instance the presence of shorter stem internodes and cormidia in material from Martinique (compare Fig. 8 I and J, and Fig. 8 K and L, respectively).

To the description of corbula by Millard & Bouillon (1973), it is worth adding the following: 1) the rachis is divided into internodes by oblique nodes slanting in opposite directions; each internode is provided with a laterodistal apophysis and two nematothecae in the axil formed by the apophyses and internode; each nematotheca is situated on one side of the rachis: one points towards the interior of the corbula, the other outwardly; 2) the costae may occasionally be branched ( Fig. 8 M), and bear up to 7 pairs of laterally placed nematothecae; 3) the latter are short, gutter-shaped, with wide aperture extending from top to base, and a small foramen communicating with the costal internode ( Fig. 8 N).

Geographical distribution. See Galea (2010a).

Figures

FIGURE 8. A – H: Halopteris tenella (Verrill, 1874) ― stem internodes and cladia (A – C); hydrothecate internodes of the stem (D); hydrotheca (E); stem ahydrothecate segments showing varied number of nematothecae (F); male (G) and female (H) gonothecae. I – N: Aglaophenia postdentata Billard, 1913 ― stem internodes in specimens from Martinique (I) and Guadeloupe (J); cormidia in specimens from Martinique (K) and Guadeloupe (L); corbula (M); internode of corbulacosta showing the shape of the nematothecae (N). Scale bars: 100 µm (N), 200 µm (I – L), 300 µm (D – H), 500 µm (A – C, M).