Antennella incerta Galea, 2010

Calder, Dale R., 2013, Some shallow-water hydroids (Cnidaria: Hydrozoa) from the central east coast of Florida, USA, Zootaxa 3648 (1), pp. 1-72 : 41

Antennella incerta Galea, 2010

Fig. 11b, c

Antennella incerta Galea, 2010: 25 , figs. 6H 1, J, K.

Type locality. Guadeloupe: Grande-Terre , L’Oeil (16°26.782´N, 61°32.405´W) ( Galea 2010: 4) .

Voucher material. West Palm Beach, on reef seaward of the Breakers Hotel, 45 feet (13.7 m), on stems of Halopteris carinata , January 1991, SCUBA, two colonies, up to 2.5 mm high, without gonophores, coll. P. Humann, ROMIZ B3973.

Remarks. Cormoids of Antennella incerta Galea, 2010 are remarkably small and slender, and specimens might easily be overlooked or mistaken for juveniles of another species. Colonies of A. incerta are distinguished in particular by having a single, laterally-displaced axillar nematotheca distal to each hydrotheca ( Fig. 11b ), and a pair of lateral nematothecae that are mug-shaped and deeply emarginated on the adcauline side, each borne on a long apophysis that reaches nearly to the hydrothecal margin ( Fig. 11c ). A perisarcal thickening marks the inner abcauline wall of the hydrotheca just above the base. Thecate internodes are saddle-shaped, and the terminal one of a hydrocladium does not extend beyond the axil between it and the hydrotheca or the bases of the nematothecal apophyses.

This is only the second report of A. incerta , extending its known range northwards from the Caribbean Sea.

Reported distribution. Atlantic coast of Florida. First record.

Western Atlantic. Florida (this study) to Guadeloupe ( Galea 2010).

Figures

FIGURE 11. a, Antennella gracilis: part of hydrocaulus with two hydrothecae, ROMIZ B1090, scale equals 0.25 mm. b, Antennella incerta: front view of hydrotheca, showing laterally-displaced axillar nematotheca, ROMIZ B3973, scale equals 0.25 mm. c, Antennella incerta: hydrocaulus with three hydrothecae, ROMIZ B3973, scale equals 0.25 mm. d, Halopteris alternata: part of hydrocaulus with a hydrocladium and two hydrothecae, ROMIZ B3974, scale equals 0.20 mm. e, Halopteris alternata: part of hydrocladium with two hydrothecae, ROMIZ B3974, scale equals 0.20 mm. f, Halopteris carinata: part of hydrocladium with two hydrothecae, ROMIZ B1128, scale equals 0.20 mm. g, Halopteris carinata: male gonotheca, ROMIZ B1128, scale equals 0.25 mm. h, Halopteris carinata: female gonotheca with two nematothecae, ROMIZ B1128, scale equals 0.25 mm.