Dynamena crisioides Lamouroux, 1824

Estrada-González, Mariae C., Agüero, José & Mendoza-Becerril, María A., 2023, Medusozoans from the Mexican Pacific: a review based on historical literature and recent observations, Journal of Natural History 57 (1), pp. 784-853 : 829

Dynamena crisioides Lamouroux, 1824

( Figure 7G, H )

Material examined

10 colonies, polyp, without gonophores; Punta Diablo, La Paz Bay , Baja California Sur, 24.316°N, 110.340°W; depth 0–3 m; 14 September 2017; on barnacles and rock; ECO-CH-Z 11755 .

Identification (after Calder 1991)

Colonies erect; hydrocaulus monosiphonic, alternately branched, divided into internodes by transverse nodes. Basal athecate internode separated from the thecatae internodes by a transverse node; thecate internodes, each with a proximal apophysis, an axillary hydrotheca, and two pairs of subopposite hydrothecae. Hydrocladia unbranched, resembling cauline internodes. Hydrothecae only contiguous in front of internodes, separated across back, adcauline wall convex, curved outwards, abcauline wall concave except for basal part. Hydrothecal margin with two large rounded lateral cusps and a smaller median adcauline cusp. Operculum formed by two valves, a large abcauline and a smaller adcauline.

Distribution

Previously recorded on the west coast of the Gulf of California, Baja California Sur ( Mendoza-Becerril et al. 2020), this report constituting the only two records for the gulf. In the MP, it has been recorded from the coasts of Guerrero and Oaxaca ( Fraser 1938a, 1948; Humara-Gil and Cruz-Gómez 2018).

Figures

Figure 7. (A, B) Ventromma halecioides (Alder, 1859): A, hydrocaulus; B, hydrotheca. (C, D) Monotheca flexuosa (Bale, 1894): C, hydrocaulus; D, hydrotheca. (E, F) Plumularia floridana Nutting, 1900: E, hydrocaulus; F, hydrotheca. (G, H) Dynamena crisioides Lamouroux, 1824: G, colony; H, hydrotheca. (I, J) Dynamena disticha (Bosc, 1802): I, colony; J, hydrotheca. (K, L) Pasya quadridentata (Ellis and Solander, 1786): K, colony; L, gonotheca. Scale bars: A, H, I, K, L = 500 μm; B, D = 100 μm; C, E = 250 μm; F, J = 200 μm; G = 1 cm. Drawings made by Nicholas Bezio.