Monotheca flexuosa (Bale, 1894)

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 : 826-828

Monotheca flexuosa (Bale, 1894)

( Figure 7C, D )

Material examined

1 colony, polyp, without gonophores; Socorro Island, Revillagigedo Islands, Manzanillo Municipality , Colima, 18.844N, 111.020°W; depth 22.3 m; 21 March 2021; on the alga Asparagopsis taxiformis and undetermined algae; ECO-CH-Z 11804 .

Identification (after Watson 2011; Calder 2020)

Colonies erect; hydrocaulus monosiphonic, alternately branched, divided into internodes by transverse nodes with rounded shoulders. Internodes flexuous, each supporting a distal hydrocladial apophysis curving smoothly away from internode and three bithalamic nematothecae, one in medial position, one axillary, and one on apophysis. Hydrocladia unbranched, divided into regular lengths of athecate and thecate internodes by transverse nodes, with rounded shoulders distally and basally to athecate and thecate internodes, respectively; athecate internode at the base of hydrocladia, straight to slightly curved, with two faint internodal septa; one thecate internode distal to hydrocladia, slightly inflated distally, bearing a hydrotheca, two faint internodal septa behind the hydrothecae and three bithalamic nematothecae, one inferior and one pair lateral without pedicels. Hydrotheca occupying almost the entire internode, cup-shaped; margin entire, circular and slight thickening below the margin.

Distribution

New record for the MP.

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.