Dynamena crisioides Lamouroux, 1824

Mendoza-Becerril, María A., Estrada-González, Mariae C., Mazariegos-Villarreal, Alejandra, Restrepo-Avendaño, Luisa, Villar-Beltrán, Rogelio D., Agüero, José & Cunha, Amanda F., 2020, Taxonomy and diversity of Hydrozoa (Cnidaria, Medusozoa) of La Paz Bay, Gulf of California, Zootaxa 4808 (1), pp. 1-37 : 19-20

Dynamena crisioides Lamouroux, 1824

Figs. 7 B–G

Dynamena crisioides Lamouroux 1824: 613 , pl. 90, Figs. 11 –12.— Humara-Gil & Cruz-Gómez 2018: 464 , Fig. 7 .

Dynamena tubuliformis Marktanner-Turneretscher 1890: 238 , pl. 4, Fig. 10 .

Thuiaria tubuliformis .— Fraser (1938a): 56.

Thuiaria crisioides .— Fraser (1948): 250.

Type locality. Moluccas, Indonesia ( Calder 1991a) .

Material examined. Polyp—PB6_1, sampling site 2 (1), mature, on rock; PB7_33, sampling site 2 (1), mature, 27°C, on a rock.

Description. Colonies erect, 0.5–1.8 mm high, arising from a creeping hydrorhiza. Hydrocaulus monosiphonic with alternate hydrocladia, irregularly divided into internodes (592.8 µm) by indistinct nodes, each with one to three pairs of subopposite hydrothecae. Exoskeleton with a visible layer corresponding to perisarc. Perisarc thick (5.9–19.8 µm wide). Hydrothecae tubular, abcauline wall concave, adcauline wall convex, adnate for most of their length (421.4–448.6 µm adnate, 99.1–152.8 µm free); 0–104.8 µm distant from adjacent hydrothecae on the same side of the internode. Hydrothecae 113.1–145.1 µm wide, aperture oval; margin with two rounded lateral cusps and a smaller median adcauline cusp; operculum with two valves; hydrothecae with or without intrathecal teeth. Gonotheca oval, 894.9–915.5 µm long, 413.5–470.4 µm wide, with distal neck and orifice nearly round (182.3–230.2 µm wide); with smooth and thin exoskeleton (5.9–8.9 µm wide), borne on hydrocladia or hydrocaulus, with short pedicel (95.4 µm long), arising from the base of hydrotheca.

Nematocysts (length x diam.). Large microbasic eurytele (16.4–18.0 x 6.3–7.4 µm).

More detailed description in Calder (1991a).

Taxonomic status. Accepted. AphiaID 418901.

Distribution. Species distributed in warm waters of all oceans ( Calder 1991a). In Mexican Pacific, it was reported in Guerrero (White Friars Islands) ( Fraser 1948, as T. crisioides ) and Oaxaca (Panteón Beach and Tangola- Tangola Bay) ( Fraser 1938a, as T. tubuliformis ; Fraser 1948, as T. crisioides ; Humara-Gil & Cruz-Gómez 2018).

Figures

FIGURE 7. A Plumularia floridana Nutting, 1900, nematocysts microbasic mastigophore. B–G Dynamena crisioides Lamouroux, 1824: B, colony; C, hydrocaulus; D, hydrothecae; E–F, gonothecae; G, nematocysts large microbasic eurytele. H–K Clytia cf. gracilis (M. Sars, 1850): H, polyp; I, hydrotheca; J, acute triangular cusps; K, hydrothecal diaphragm. Scale equals A—332 µm; B—0.4 mm; C, E—500 µm, D, F, H, I—200 µm; G—17 µm; J—160 µm, K—50 µm.

FIGURE 10. A Obelia dichotoma (Linnaeus, 1758), nematocysts microbasic b-mastigophore type A. B–I Obelia tenuis Fraser, 1938a: B–D, colony; C, Paralectotype (USNM 49309); E, stem monosiphonic and branches; F, hydrothecal pedicels with annulations and gonothecae; G, nematocysts microbasic b-mastigophore type A; H, hydrothecae; I, gonothecae. Scale equals A–11 µm; B–800 µm; C—330 µm; D—2 mm, E—500 µm; F, H—200 µm; G—10 µm; I—100 µm.

FIGURE 11. A–F Obelia spp.: A, medusa; B, manubrium; C, gonads spherical; D, tentacles; E, statocyst; F, nematocyst; a, isorhiza; b, microbasic b-mastigophore. Scale equals A, C—500 µm; B, D, E—50 µm; F—20 µm.