Los Molinos (near Valdivia), Chile Lucernaria janetae 8[degrees] 37' North on the East Pacific Rise Table 2 Size and distribution of nematocysts of Lucernaria janetae Tissue Nematocyst n N Range Subumbrellar vesicle Eurytele B, C 34 3/3 19.3-12.2X6.2-8.9 Holotrich A 34 3/3 20.4-16.4X2.2-4.3 Tentacle Eurytele B, C 34 3/3 15.5-12.6X6.4-7.7 Holotrich A 34 3/3 21.8-18.3X2.9-4.5 Gastric filament Eurytele B, C 31 3/3 12.1-10.8X8-8.8 Letters refer to Figure 4; "N" is the proportion of examined specimens that had a particular type of nematocyst; "n" is the number of capsules measured; size presented as range of lengths by widths, in micrometers, for undischarged capsules.
Pieces of tissue from tentacles, subumbrellar vesicles, and gastric filaments were smeared on a slide; nematocysts in these smears were examined using differential interference contrast microscopy at 100X magnification.
Each gametogenic pad extends from the base of the calyx into the base of the arms; proximal portion of pads separated by gastric filaments. Gastric filaments opaque cream, long, slender, bluntly pointed, restricted to base of calyx, between gametogenic pads.
Members of Stauromedusae possess features that appear to be homologous with those of Cubozoa and Scyphozoa, such as intramesogleal muscles of the polyp, gastric filaments, hollow structures ontogenetically derived from primary polyp tentacles known as anchors or rhopalioids, and a metamorphosis from juvenile to adult morphology concentrated at their oral ends (Uchida, 1929; Hirano, 1986; Kikinger and Salvini-Plawen, 1995).
Few gastric filaments attached to stomach wall near opening of gonadal sac.
Gastric filaments occur only in medusae [less than or equal to] 8.2 cm bd (Larson, 1987).
larsoni (see also Larson, 1987) indicates that Drymonema resorbs gastric filaments between 6.2 and 10.9 cm bd such that gastric filaments are absent from larger medusae.
The allomorphic morphology of Drymonema, including the allometric loss of gastric filaments and massive elaboration of the oral arms (Larson, 1987), is likely functionally related to dietary specialization.