Dynamena disticha

Size

Colony height: reaching 1cm (0.4").

Recognition Characters

Colonies erect arising from creeping hydrorhiza. Hydrocaulis monosiphonic, straight, and unbranched; divided into internodes. Internodes vase-shaped separating each pair of hydrothecae. Hydrothecae arise directly from hydrocaulis in opposite pairs, somewhat cylindrical in shape, proximal half parallel with axis of internode, distal end flaring outward at 45° angle. Hydrothecae has 2 large lateral teeth and 1 small median adcauline tooth on dorsal side of operculum.

Color

Somewhat translucent to brown or tan

Habitat & Depth

Largely epiphytic attaching to other seaweeds, grasses, and algae or ascidians, other hydroids, and sponges. Shallow intertidal, open water pelagic zones, reefs.

Distribution at GRNMS

Occasional. Found attached to Sargassum, or other invertebrates.

Geographic Range

Wide Circumtropical distribution. Eastern and Western Atlantic, Pacific and Indian Oceans

Behavior & Notes

Gonophores are fixed sporosacs.

Synonyms

Dynamena cornicina (McCrady, 1859)

References

Calder 1991