Aequorea

Description. Colonies minute, mainly stolonal, with erect shoots comprising 1 – 2 hydrothecae; stolon creeping. Pedicels of variable length (120 – 235 µm), spirally grooved nearly throughout, smooth below hydrotheca; diameter gradually widening from base (35 – 45 µm) towards distal end (60 – 75 µm). Hydrotheca ovate, 235 – 270 µm long, 120 – 155 µm wide in middle, tapering apically to form a conical, pleated operculum, with pointed tip; folds continuing downwards nearly to base; the latter square in shape, 100 – 130 µm wide. Hydranth with ca. 20 amphicoronate tentacles; intertentacular web present. Nematocysts (undischarged): large capsules of unidentified type (11.4 – 12.0) × (3.7 – 3.9) µm; microbasic (?) mastigophores (6.3 – 6.8) × (2.0 – 2.1) µm.

Remarks. Due to the lack of knowledge of the medusa stage, this material could not be identified to species level. Several nominal species (medusa stage) of Aequorea have been reported from the western Atlantic (see Kramp 1959 a), but their complete life cycles are unknown.

Material examined. Stn. 3: 01.04.2008 — several hydrothecae but no gonothecae, on algae. Stn. 7: 25.03.2008 — a small, sterile colony, with both stolonal and minute erect stems, on algae; 27.03.2008 — a minute, sterile, stolonal colony, on alga.