Antennella quadriaurita Ritchie 1909

• Main Author: Galea, Horia R.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2013
• Subjects: Biodiversity; Taxonomy; Animalia; Cnidaria; Hydrozoa; Leptothecata; Halopterididae; Antennella; Antennella quadriaurita; Gough; Inaccessible Island; Indian; Tristan
• Online Access: https://zenodo.org/record/5263649; https://doi.org/10.5281/zenodo.5263649

Antennella aff. quadriaurita Ritchie, 1909 (Fig. 7 K–N) Material examined. Stn. 8, 27.i.2012, 9– 15 m, M076: fertile (female) colony on Thyroscyphus marginatus (Allman, 1877). Additional material for comparison: Tristan da Cunha group, Inaccessible Island, Stn 7. I10, 28.xi. 2007, HRG-0341: several sterile stems. Remarks. Compared to the material from Inaccessible Island studied earlier by myself (Galea 2010 b), the present specimens have smaller hydrothecae, the lateral nematothecae of the anterior pair are shorter (compare Fig. 7 M 1 and M 2), and the ahydrothecate segments bear 3 or 4 nematothecae in two parallel, closely set rows (Fig. 7 K), instead of only one, occasionally two. The cnidome of the Caribbean material is composed of three types of capsules (Fig. 7 N 1): 1) seed-shaped microbasic heteronemes, ca. 4.2 × 2.6 µm, occurring rarely in the coenosarc; 2) small, banana-shaped microbasic mastigophores, ca. 6.4 × 2.2 µm, abundant in the tentacles, also scattered in the coenosarc; 3) large, ovoid microbasic heteronemes with thick shaft (pseudostenoteles?), (14.1 –16.0)×(5.6–6.4) µm, occurring in the nematophores, also scattered in the coenosarc. In contrast, the large microbasic heteronemes in material from Inaccessible Island are smaller, slender, and more tubular [(11.2–12.5)×(3.8 –4.0) µm], and their shaft is less conspicuous (Fig. 7 N 2). Given: 1) the extreme variability in size of the stems and the number of hydrothecae they carry [from 1.4 cm high and 9 hydrothecae in Ritchie's (1909) material from Gough Island, to up to 6 cm high and 40 hydrothecae in the Indian specimens studied by Leloup (1932)]; 2) the shape (walls parallel or divergent) and size of the hydrothecae; 3) the shape of the upper chamber of the first pair of lateral nematothecae (see variation in Schuchert 1997); 4) the varied number of nematothecae (from 1 to 4) carried by the ahydrothecate segments (Millard 1977); 5) the lack of data on the cnidome composition in nearly all the previous records from around the world; 6) the lack ...