Aglaura hemistoma Péron & Lesueur

Nagata, Renato Mitsuo, Júnior, Miodeli Nogueira & Haddad, Maria Angélica, 2014, Faunistic survey of Hydromedusae (Cnidaria, Medusozoa) from the coast of Paraná State, Southern Brazil, Zootaxa 3768 (3), pp. 291-326 : 316-317

Aglaura hemistoma Péron & Lesueur

( Figs 36–37 )

References consulted. Mayer 1910: 398–401, pl. 49, figs 3–7 figs 250–251. Vannucci 1957: 76–79. Kramp 1961: 251. Goy 1979: 284–285, fig. 25. Pagès et al. 1992: 44–45, fig. 53. Bouillon 1999: 437, fig. 3.170. Bouillon et al. 2004: 241, figs 16 A, 152 G. Tronolone 2007: 71–72, fig. 2.32.

Material. Municipality of Pontal do Paraná, Balneário de Praia de Leste (25º44’15”S – 48º21’60”W): 01/12/ 1997 — 1 specimen; (25º50’25”S – 47º55’80”W): 01/12/1997 — 4 specimens; (25º50’25”S – 47º55’80”W): 20/02/ 1998 — 4 specimens; (25º46’32”S – 48º12’15”W): 31/03/1998 — 3 specimens; (25º48’10”S – 48º04’90”W): 31/03/ 1998 — 14 specimens; (25º42’65”S – 48º27’85”W): 22/04/1998 — 1 specimen; (25º44’15”S – 48º21’60”W): 22/04/ 1998 — 2 specimens; (25º48’10”S – 48º04’90”W): 22/04/1998 — 10 specimens; (25º50’25”S – 47º55’80”W): 22/04/ 1998 — 53 specimens; (25º44’15”S – 48º21’60”W): 27/05/1998 — 4 specimens; (25º46’32”S – 48º12’15”W): 27/05/ 1998 — 46 specimens; (25º48’10”S – 48º04’90”W): 27/05/1998 — 19 specimens; (25º50’25”S – 47º55’80”W): 27/05/ 1998 — 43 specimens; (25º44’15”S – 48º21’60”W): 24/06/1998 — 8 specimens; (25º46’32”S – 48º12’15”W): 24/06/ 1998 — 11 specimens; (25º44’15”S – 48º21’60”W): 16/07/1998 — 1 specimen; (25º48’10”S – 48º04’90”W): 16/07/ 1998 — 9 specimens; (25º50’25”S – 47º55’80”W): 16/07/1998 — 21 specimens; (25º42’65”S – 48º27’85”W): 20/08/ 1998 — 1 specimen; (25º44’15”S – 48º21’60”W): 20/08/1998 — 1 specimen; (25º50’25”S – 47º55’80”W): 02/10/ 1998 — 40 specimens; (25º50’25”S – 47º55’80”W): 28/10/1998 — 1 specimen; (25º50’25”S – 47º55’80”W): 25/11/ 1998 — 8 specimens; (25º50’25”S – 47º55’80”W): 21/12/1998 — 2 specimens; (25º42’65”S – 48º27’85”W): 22/01/ 1999 — 2 specimens; (25º46’32”S – 48º12’15”W): 24/02/1999 — 4 specimens; (25º48’10”S – 48º04’90”W): 24/02/ 1999 — 26 specimens; (25º50’25”S – 47º55’80”W): 24/02/1999 — 11 specimens; (25º46’32”S – 48º12’15”W): 24/03/ 1999 — 4 specimens; (25º48’10”S – 48º04’90”W): 24/03/1999 — 8 specimens; (25º50’25”S – 47º55’80”W): 24/03/ 1999 — 25 specimens.

Reference specimens deposited. MZUSP 1505, 1 specimen. Dzoo-Cn 253, 4 specimens.

World distribution. In the three great oceans and the Mediterranean Sea, abundant in tropical and subtropical waters ( Mayer 1910; Bouillon 1999; Bouillon et al. 2004).

Distribution in Brazil. Near the Fernando de Noronha Archipelago and from the state of Pernambuco to Rio Grande do Sul (Migotto et al. 2002).

Description. Umbrella with parallel walls, apex flattened, 0.75–3.75 mm in height ( Fig 36 ). Eight radial canals. Long thin gastric peduncle, mouth with 4 simple lips. Eight gonads attached on peduncle ( Fig. 37 ), spherical in younger individuals and elongating to sausage-shaped in fully developed medusae. Umbrellar margin with numerous and juxtaposed short tentacles, with distal portion club-shaped. In undamaged specimens, tentacular length about ¾ of the umbrellar diameter, however tentacacles usually broken because of collection with nets. Eight statocysts.

Systematic remarks. Aglaura Péron & Lesueur is a monotypic genus. The shape and consistency of the umbrella are typical of species of Rhopalonematidae . Because of their rigidity, specimens generally retain their shape. The shape and position of the gonads on the gastric peduncle distinguish A. hemistoma from apparently similar species with records in Brazil, such as Aglantha digitale (F. Müller) and Amphogona apicata Kramp.

Biological data. Despite its preference for coastal waters on the Catalonia coast, Mediterranean Sea ( Gili et al. 1988; Bouillon et al. 2004), A. hemistoma is generally considered a warm-ocean and epipelagic species that occasionally visits the coastal region, such as: in the Adriatic Sea ( Benović & Bender 1987; Lucić et al. 2009) and the Gulf of Tunis ( Daly Yahia et al. 2003), both in the Mediterranean; in the Bay of Bengal, Indian Ocean ( Santhakumari 1993); and in the southern Benguela Current (Buecher & Gibbons 2000). On the Brazilian coast, the medusa is dominant on the middle and outer shelf, associated with Tropical Water, and occasionally enters coastal waters, tolerating salinities from 33 to 36.9 ( Vannucci 1957, 1963; Tronolone 2007; Nogueira 2011). Moreira (1973) and Nogueira (2011) studied the diel vertical migration of the species, which aggregates on the surface at night. Colin et al. (2005) described an omnivorous diet of the species, including tintinnids and copepods.

Figures

FIGURE 33 – 37. Solmaris corona (Keferstein & Ehlers): young medusae (33); Liriope tetraphylla (Chamisso & Eysenhardt): adult (34), and young medusae (35) a courtesy of Luis Eduardo de Mattos Pukanski; Aglaura hemistoma Péron & Lesueur: adult medusae (36) gonads attached on peduncle (37).