Chrysaora lactea Eschscholtz, 1829

Morandini, André C. & Marques, Antonio C., 2010, Revision of the genus Chrysaora Péron & Lesueur, 1810 (Cnidaria: Scyphozoa) 2464, Zootaxa 2464, pp. 1-97 : 31-37

Chrysaora lactea Eschscholtz, 1829

( Figures 39 –43, 78, 90)

Chrysaora lactea Eschscholtz 1829: 81–82 (original description), Pl. VII fig. 3 (medusa) [Bay of Rio de Janeiro – Brazil]. Blainville 1834: 299 (mention), Pl. XXXVI fig. 4. Lesson 1843: 397 (brief description). Claus 1877: 36 (mention). Kramp 1955: 299 (mention, differences between C. lactea and C. quinquecirrha ). Vannucci 1957: 594, 595, 596 (mention). Kramp 1961: 326 (synonymy). Vannucci & Tundisi 1962: 210 (mention, distribution) [Maldonado – Uruguay; Puerto Belgrano, Necochea, Mar del Plata – Argentina]. Goy 1979: 267 (list). Mianzan, Olague & Montero 1988: 3 (tab. 1), 4 (mention) [Maldonado, Punta del Este, La Paloma, A. Solís Grande – Uruguay]. Mianzan 1989a: 30 (mention) [Baía Blanca – Argentina]. Mianzan 1989b: 18–19 (brief description), fig. 3 (medusa), fig. 4 (ephyra) [Samborombón, Mar del Plata, Baía Blanca, Pinamar – Argentina]. Cornelius & Silveira 1997: 193 (mention). Mianzan & Cornelius 1999: 538 (description), fig. 2.15 (distribution), figs 5.15a–b (medusa), fig. 5.15c (ephyra) [South Atlantic]. Silveira & Cornelius 2000: 11 (mention, Tab. 1). Gershwin & Collins 2002: 128 (mention), 129 (tab. 1), 130 (mention), 133 (mention), 142 (key), fig. 2 (phylogeny). Migotto, Marques, Morandini & Silveira 2002: 22 (tab. 1), fig. 36 (medusa) [ Brazil]. Tronolone, Morandini & Migotto 2002: 5 (ephyrae description), figs. 4– 7 (ephyra) [São Sebastião Channel – Brazil]. Morandini, Silveira & Jarms 2004: 347–352 (life cycle), figs 1–2 (polyps), fig. 3 (podocyst), figs 4–5 (strobila), fig. 6 (ephyra), fig. 7 (development of first tentacles), figs 8–9 (medusa) [Cananéia – Brazil]. Morandini, Ascher, Stampar & Ferreira 2005a: 285 (description), 290 (key), figs 8–9 (medusae) [São Paulo state – Brazil]. Morandini, Martorelli, Marques & Silveira 2005b: 40–41 (occurrence of digenean parasites), 43 (mention), 44 (feeding) [Cananéia – Brazil]. Bayha 2006a: 82, 86, 88–90, 94–96, 98, 100, 102, 107–109, 111–112 (mention), 124, 126–128 (table), figs 3–2 (collection map), 3–4, 3–5, 3–6 (phylogenies) (molecular systematics) [Rio de Janeiro – Brazil; Rio de la Plata – Argentina]. Morandini, Silveira & Cornelius 2006a: 29–41 (redescription), fig. 1 (adult medusa), fig. 2 (exumbrellar view of octant showing papillae pattern), fig. 3 (medusa, side view), fig. 4 (subumbrellar view of octant with radial septa shape), fig. 5 (oral arm), fig. 6 (colour variation of medusae), fig. 7 (polyp), fig. 8 (strobila), fig. 9 (development of first tentacles), fig. 10 (cnidome) [Alagoas, Bahia, Ceará, Rio de Janeiro and São Paulo – Brazil; Argentina; Uruguay]. Morandini, Soares, Matthews-Cascon & Marques 2006b: 4 (description) [Ceará state – Brazil]. Nogueira Jr. & Haddad 2006a: 1231–1234 (size weight relationship) [Paraná – Brazil]. Nogueira Jr. & Haddad 2006b: 1161–1164 (occurrence) [Paraná – Brazil]. Martinelli Filho, Stampar, Morandini & Mossolin 2008: 133–140 (cleaner shrimp association) [southeastern Brazil]. Arai 2009: 243 (podocysts). Bayha & Graham 2009: 221 (molecular identification of polyps). Calder 2009: 26 (mention).

Chrysaora blossevillii Lesson 1830: 115–116 (original description), Pl. XIII fig. 2 (medusa) [Santa Catarina – Brazil]. Lesson 1843: 401 (description) [Santa Catarina Island – Brazil].

Dactylometra lactea: L. Agassiz 1862: 126 , 166 (mention). Haeckel 1880: 517 (description) [Rio de Janeiro – Brazil]. von Lendenfeld 1884: 271 (description) [Rio de Janeiro – Brazil]. Vanhöffen 1888: 47 (distribution). A. Agassiz & Mayer 1898: 7–8 (description), Pl. VII fig. 10 (rhopalium), Pls XII–XIII (medusa) [Havana Harbour – Cuba]. Maas 1910: 43 (mention). Mayer 1910: 583–584 (description), figs 369–370 (medusa). Bigelow 1913: 91 (mention, table) [Santiago – Cuba]. Stiasny 1919: 76 (mention, comparison with D. quinquecirrha ). Ranson 1949: 141–142 (description) [Cabo La Vela – Colombia]. Thiel 1966: 20, 21 (mention).

Lobocrocis blossevillii: L. Agassiz 1862: 166 (mention).

? Pelagia volutata Couthoy in L. Agassiz 1862: 127 (mention).

? Zygonema volutata: L. Agassiz 1862: 127 , 166 (mention).

Chrysaora blossevillei: Haeckel 1880: 514 (description) [Santa Catarina – Brazil]. von Lendenfeld 1884: 268–269 (description) [Santa Catarina – Brazil]. Mayer 1910: 579 (synoptic table). Stiasny 1937: 273, 275 (mention). Kramp 1961: 324 (synonymy, considered the species doubtful). Vannucci 1954: 125 ( C. blossevillei = C. hysoscella ). Gershwin & Collins 2002: 128 (mentioned as nominal species with insufficient data).

? Chrysaora blossevillei: Vanhöffen 1888: 15–16 (description), 23 (brief description), 47 (distribution), Pl. I fig. 3 (medusa) [Pernambuco – Brazil].

Chrysaora blossevillei var. plocamia Mayer 1910: 581 (brief description). Stiasny 1937: 273, 275 (mention) [non Chrysaora plocamia ( Lesson, 1830) ].

Chrysaora hysoscella var. blossevillei Mayer 1910: 579 , 581 (brief description). Vannucci 1957: 594 (mention, = C. hysoscella ) [Pernambuco, Santa Catarina – Brazil].

Dactilometra lactea: Oliveira 1950: 369 (mention), 389 (mention) [Rio de Janeiro - Brazil].

Chrysaora hysoscella: Vannucci 1954: 123–126 (description), Pl. VI figs 1–2 [Cananéia – Brazil]. Vannucci 1957: 594, 595 (mention). Goy 1979: 267 (list), 289 (brief description) [Montevideo – Uruguay]. Mianzan, Olague & Montero 1988: 3 (tab. 1), 4 (mention) [Punta del Este – Uruguay]. Mianzan 1989b: 19–20 (brief description), figs 5a–b (medusa) [Puerto Madryn, Ushuaia – Argentina] [non Chrysaora hysoscella ( Linnaeus, 1767) ].

Chrysaora quinquecirrha: Goy 1979: 267 (list), 291 (brief description) [Southern Brazil, Uruguay]. Larson 1982: 256 (list) [Carrie Bow Cay – Belize]. Mianzan, Olague & Montero 1988: 3 (tab. 1), 4 (mention) [ Uruguay]. Duffy, Epifanio & Fuiman 1997: 123–130 (predation over fish) [Port Aransas, Texas – USA]. Graham 2001: 97–110 (numerical increases) [Gulf of Mexico]. Segura-Puertas, Suárez-Morales & Celis 2003: 9 (list) [Gulf of Mexico] [non Chrysaora quinquecirrha ( Desor, 1848) ].

Neotype specimen. The holotype is lost, and a neotype specimen was designated by Morandini et al. (2006a). MZUSP 897 (~ 10 cm in diameter, 17.xi.1998, preserved in 4% formaldehyde solution, São Sebastião , São Paulo – Brazil).

Examined material. Neotype; MNHN Inv. M. 1715 (as C. hysoscella , ~ 1 cm in diameter, 27.xii.1961, 4% formaldehyde solution, off Uruguay), MNHN Inv. M. 1716 (as C. quinquecirrha , specimens ~4, 5, and 6 cm in diameter, 27.xii.1961, 4% formaldehyde solution, off Uruguay); MNRJ 181 (15.x.1976, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 182 (Rio de Janeiro – Brazil), MNRJ 183 (as C. blossevillei , ~ 8 cm in diameter, no date, ethanol, Guanabara Bay, Rio de Janeiro – Brazil), MNRJ 961 (18.x.1986, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 1027 (16.ii.1986, Niterói, Rio de Janeiro – Brazil), MNRJ 1028 (31.iii.1979, Rio de Janeiro – Brazil), MNRJ 1030 (20.ii.1986, Ilha Grande, Rio de Janeiro – Brazil), MNRJ 1032 (26.i.1986, Rio de Janeiro – Brazil), MNRJ 1033 (13.v.1982, Cabo Frio, Brazil), MNRJ 1034 (08.i.1981, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 1035 (01.i.1984, Cabo Frio – Brazil), MNRJ 1221 (Rio de Janeiro – Brazil), MNRJ 1361 (Rio de Janeiro – Brazil), MNRJ 1668 (28.ii.1979, Rio de Janeiro – Brazil), MNRJ 1673 (28.ii.1979, Rio de Janeiro – Brazil), MNRJ 1674 (21.i.1979, Rio de Janeiro – Brazil), MNRJ 1675 (04.ix.1982, Rio de Janeiro – Brazil), MNRJ 1676 (22.i.1979, Rio de Janeiro – Brazil), MNRJ 1677 (01.ix.1978, Cabo Frio – Brazil), MNRJ 1678 (11.i.1988, Cabo Frio – Brazil), MNRJ 1681 (16.i.1990, Arraial da Ajuda, Bahia – Brazil), MNRJ 1694 (26.ii.1990, Rio de Janeiro – Brazil), MNRJ 1941 (15.ii.1991, Maceió, Alagoas – Brazil), MNRJ 2791 (30.i.1992, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 2793 (05.xii.1980, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 2794 (07.vii.1988, Cabo Frio, Rio de Janeiro – Brazil), MNRJ 3237 (04.ii.1997, Ilha do Cardoso, São Paulo – Brazil); MZUSP 340 (specimens ~10 and 11 cm in diameter, 30.xi.2002, 4% formaldehyde solution in seawater, Ubatuba, São Paulo – Brazil), MZUSP 341 (specimens ~5.5, 6.5, 7, 7, 7, 8, and 8.5 in diameter, 10.viii.2002, 4% formaldehyde solution in seawater, Guarujá, São Paulo – Brazil), MZUSP 342 (~ 8 cm in diameter, 15.xii.1999, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil,) MZUSP 361 (~ 4 cm in diameter, 26.xii.2002, 4% formaldehyde solution in seawater, lab cultured – Brazil), MZUSP 362 (~ 3 cm in diameter, 26.xii.2002, 4% formaldehyde solution in seawater, lab cultured – Brazil), MZUSP 363 (24.ix.2001, 4% formaldehyde solution in seawater, ephyrae lab cultured – Brazil), MZUSP 364 (20.ii.2002, 4% formaldehyde solution in seawater, ephyrae lab cultured – Brazil), MZUSP 365 (12.vi.2003, 4% formaldehyde solution in seawater, scyphistomae from lab cultures – Brazil), MZUSP 474 (specimens ~2.5, 4.5, 4.5, and 5.5 cm in diameter, 1990–1992, 4% formaldehyde solution in seawater, Fortaleza, Ceará – Brazil), MZUSP 764 (specimens ~2.5, 2.5, 4, 4.5, 4.5, 4.5, 4.5, 5, 5, 5.5, 5.5, 6, and 10 cm in diameter, xi.1996, 4% formaldehyde solution in seawater, Comprida Island, São Paulo – Brazil), MZUSP 78 (~ 6.5 cm in diameter, 05.ii.2002, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 791 (~ 2 cm in diameter, 26.x.1996, 4% formaldehyde solution in seawater, Comprida Island, São Paulo – Brazil), MZUSP 797 (~ 3 cm in diameter, 09.i.2002, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 799 (~ 6 cm in diameter, 09.vii.1995, 4% formaldehyde solution in seawater, São Sebastião, São Paulo – Brazil), MZUSP 802 (~ 4 cm in diameter, 18.ii.2004, 4% formaldehyde solution in seawater, lab cultured – Brazil), MZUSP 803 (specimens ~2, 2.5, 3, 3, 3, 3, 3, 3, 4, and 5.5 cm in diameter, 29.xi.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 804 (~ 6 cm in diameter, 27.vi.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 807 (~ 6 cm in diameter, 29.v.2004, 4% formaldehyde solution in seawater, lab cultured – Brazil), MZUSP 809 (~ 5 cm in diameter, 22.iii.2000, 4% formaldehyde solution in seawater, Comprida Island, São Paulo – Brazil), MZUSP 811 (~ 6 cm in diameter, 24.v.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 822 (specimens ~2 and 7 cm in diameter, 22.i.2004, 4% formaldehyde solution in seawater, lab cultured – Brazil), MZUSP 824 (specimens ~5, 5.5, 7, 8.5, and 8.5 cm in diameter, 15.ii.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 825 specimens (~4, 4.5, 4.5, 5, 7, 7.5, 7.5, 8, and 10 cm in diameter, 09.xi.1999, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 826 (specimens ~6, 6.5, 7, 8, and 8.5 cm in diameter, 25.v.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 828 (specimens ~5, 6, 7, 8.5, 8.5, and 9 cm in diameter, 11.xi.1999, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 829 (~ 8.5 cm in diameter, 27.vi.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), MZUSP 830 (~ 13.5 cm in diameter, 05.xii.1999, 4% formaldehyde solution in seawater, São Sebastião, São Paulo – Brazil); MZUSP 1471 (~ 12 cm in diameter, 27.iii.2007, 4% formaldehyde solution in seawater, Santana Archipelago, Macaé, Rio de Janeiro – Brazil); MZUSP 1472 (~ 16 cm in diameter, 27.iii.2007, 4% formaldehyde solution in seawater, Santana Archipelago, Macaé, Rio de Janeiro – Brazil); MZUSP 1473 (~ 15 cm in diameter, 27.iii.2007, 4% formaldehyde solution in seawater, Santana Archipelago, Macaé, Rio de Janeiro – Brazil); MZUSP 1474 (~ 11 cm in diameter, 27.iii.2007, 4% formaldehyde solution in seawater, Santana Archipelago, Macaé, Rio de Janeiro – Brazil); MZUSP 1475 (~ 12 cm in diameter, 24.ii.1997, 4% formaldehyde solution in seawater, Cabras island, Ilhabela, São Paulo – Brazil); MZUSP 1476 (~ 14 cm in diameter, 24.ii.1997, 4% formaldehyde solution in seawater, Cabras island, Ilhabela, São Paulo – Brazil); MZUSP 1477 (~ 16 cm in diameter, 17.ix.1998, 4% formaldehyde solution in seawater, São Sebastião, São Paulo – Brazil); NHM 1997.998 (~ 6 cm in diameter, 08.iii.1983, 4% formaldehyde solution, Pinamar – Argentina), NHM 1997.999 (~ 8 cm in diameter, 08.iii.1983, 4% formaldehyde solution, Pinamar – Argentina), NHM 1997.1000 (~ 3.5 cm in diameter, 17.ii.1983, 4% formaldehyde solution, Canal Storto, Bahia Blanca – Argentina), NHM 1997.1001 (~ 9 cm in diameter, 09.ii.1983, 4% formaldehyde solution, Ingeniero White, Baía Blanca – Argentina); USNM 42155 (as? Dactylometra dactylometra , specimens ~6.5 and 8 cm in diameter), ethanol, Louisiana – USA), USNM 49733 (as C. quinquecirrha , ~ 4.5 cm in diameter, 09.x.1950, ethanol, Alligator Harbor, Franklin County, Florida – USA), USNM 53753 (as Dactylometra lactea , specimens ~10, 12, and 12 cm in diameter, 25.v.1963, 4% formaldehyde solution, Jamaica), USNM 53826 (as C. quinquecirrha , specimens ~6.5 and 7.5 cm in diameter, 18.vii.1939, 4% formaldehyde solution, Timbalier Bay, Louisiana – USA), USNM 54405 (as C. blossevillei , as C. hysoscella , specimens ~9 and 12 cm in diameter, 05.ii.1939, 4% formaldehyde solution, Guanabara Bay, Rio de Janeiro – Brazil), USNM 54437 (as C. cf. quinquecirrha , ~ 15 cm in diameter, 24.xi.1973, 4% formaldehyde solution, Mayaguez Harbor – Puerto Rico), USNM 54438 (as C. cf. quinquecirrha , specimens ~8.2, 10, 11, and 14.5 cm in diameter, 28.ix.1974, 4% formaldehyde solution, Mayaguez Harbor – Puerto Rico), USNM 54439 (as C. cf. quinquecirrha , specimens ~12, 13, 13, and 14.5 cm in diameter, 28.ix.1974, 4% formaldehyde solution, Mayaguez Harbor – Puerto Rico), USNM 54440 (as C. sp., specimens ~4.5 and 5 cm in diameter, 21.vii.1975, 4% formaldehyde solution, St. John Island, Virgin Islands – USA), USNM 54441 (as Dactylometra lactea , ~ 6.2 cm in diameter, 27.viii.1974, San Juan Harbor – Puerto Rico), USNM 56653 (as C. quinquecirrha , ~ 12 cm in diameter, 09.xi.1973, ethanol, between Venado Island and Bruja Point, 08º53,02’N 079º35,18’W – Panama), USNM 57923 (as C. quinquecirrha , ~ 5.6 cm in diameter, 08.ii.1978, 4% formaldehyde solution, Stann Creek, Dangriga – Belize), USNM 57924 (as C. quinquecirrha , ~ 4.2 cm in diameter, 08.ii.1978, 4% formaldehyde solution, Stann Creek, Dangriga – Belize), USNM 1073337 (as C. sp., specimens ~2.5 and 4 cm in diameter, 17.iii.2004, 4% formaldehyde solution, Bocas del Toro – Panama); ZMH C11673 (specimens ~8 and 9 cm in diameter, 15.iii.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil), ZMH C11674 specimens (~6, 8, and 9 cm in diameter, 15.iii.2000, 4% formaldehyde solution in seawater, Cananéia, São Paulo – Brazil).

Type locality. Guanabara Bay, Rio de Janeiro, Brazil.

Distribution. Western North and South Atlantic; from Gulf of Mexico to northern Argentina coast ( Fig. 78).

Diagnosis. Live and preserved medusae 6–11 cm in diameter (maximum 25 cm in diameter); marginal lappets rounded (adults), 4–6 per octant, without canals; mature specimens with 24–40 tentacles (3–5 tentacles per octant), primary tentacle central, 2 secondary tentacles most peripheral, and tertiary tentacles between primary and secondary (2-3-1-3-2); quadralinga absent; colouration (adults) exumbrella background usually milky-white, some specimens with small brown spots on exumbrella and oral arms, other specimens with a radial pattern of brownish triangles.

Descriptions and data based on Morandini et al. (2006a).

Neotype description. Umbrella almost hemispherical, diameter 10 cm. Exumbrellar surface finely granulated, transparent-whitish. Mesoglea flexible, about 1 cm thick on central portion, thinning towards margin. Marginal lappets round, sharper at tip, 6 per octant (2 rhopalar and 4 tentacular); rhopalar lappets slightly longer and broader than tentacular ones. Rhopalia 8, without ocelli, in deep clefts; exumbrellar sensory pit deep, blind-ended. Tentacle clefts vary in depth. Tentacles 40 (5 per octant, Fig. 41), as long as umbrellar diameter (longer in life); arranged as 2-3-1-3-2 (primary tentacle central, 2 secondary tentacles most peripheric and tertiary tentacles between primary and secondary). Subumbrellar and tentacular musculature not distinguishable. Mouth-disc circular, with four evident corners, grooved. Pillars evident, 2.5 cm wide, delimited by corners of insertion of manubrium. Subgenital ostia oval, 0.5 cm in diameter. Oral arms ca. 7 cm long, V-shaped in cross section, edges delicate and convoluted, distal portion slightly spiral, distal 1/3 with reduced V-shaped free edge in cross section. Central stomach circular, marginal region limited by insertion of radial septa. Stomach pouches 16, width uniform centrally; tentacular pouches enlarged distally. Septa narrow, wider at proximal end (pear-shaped); outer 1/3 bending towards rhopalia (~45º) ending straight into the margin, proximal region of the radial septa hard to see, due to enlarged mouth-disc (Fig. 41). Gastric filaments in four interradial fields. Quadralinga absent. Gonads rimming gastric filaments, in semicircle, greatly folded; female.

Description of other specimens and additional data. Medusa: Umbrella diameter up to 25 cm, almost hemispherical ( Figs 39 –40), flat in younger specimens (0.5–3 cm), varied in preserved specimens. Some specimens with small irregular papillae on exumbrella and oral arms. Colouration highly variable, transparentwhitish background with irregularly distributed small reddish-brown spots (warts); completely whitish; milky white background with a radial pattern of brownish triangles and irregularly distributed small reddish-brown spots (papillae) (see also Morandini et al., 2005a, fig. 8 and Morandini et al., 2006a, fig. 6 for different colour patterns). Marginal lappets round, 2–6 per octant (2 in younger specimens); rhopalar lappets slightly wider than tentacular. Rhopalia yellowish (in vivo). Tentacles up to 40 (5 per octant) ( Figs 39, 41); primary tentacle central, 2 secondary tentacles most peripheral and tertiary tentacles between primary and secondary (2-3-1-3- 2). Pillars evident, in some specimens coloured strongly reddish-brown or with irregularly-distributed small reddish-brown spots. Gonad colour variable: whitish, yellowish-brown to pale pink. Planula. Elongate, pearshaped; 0.14–0.2 mm long, 0.06–0.09 mm wide; whitish. Scyphistoma (Fig. 42). Conical to goblet-shaped, up to 2.2 mm high; oral disc up to 1.2 mm wide; tentacles typically 16 (12–21), length up to 5 times polyp height; mouth cruciform, with prominent lips elevated from the oral disk; gastric septa 4; whitish to cream. Podocysts. Trapezoid, diameter 0.2–0.3 mm, height 0.08–0.1 mm; yellowish-brown. Strobila. Polydisc (2–10 ephyrae), whitish, strobilation lasting about 10 days. Ephyra (Fig. 43): typically with 8 arms (lobes); marginal lappets 16, pointed; rhopalia 8, with light yellowish concretions; mouth cruciform; diameter 1 mm just after liberation; transparent; with one nematocyst cluster on each side of rhopalium. Cnidome ( Fig. 90): Specimen MZUSP 1471, medusa tentacles with holotrichous O-isorhizas [n=10; 16.6–18.6 x 13.7–16.6 µm (mean = 18.03 x 14.90 µm)]; holotrichous a-isorhizas [n=10; 7.8–8.8 x 3.9–4.9 µm (mean = 8.13 x 4.41 µm)]; holotrichous A-isorhizas [n=10; 17.6–19.6 x 9.8–11.7 µm (mean = 18.72 x 10.29 µm)]; heterotrichous microbasic rhopaloids [n=10; 11.7–13.7 x 5.8–7.8 µm (mean = 12.35 x 6.96 µm)]; Specimen MZUSP 1472, medusa tentacles with holotrichous O-isorhizas [n=10; 14.7–19.6 x 12.7–18.6 µm (mean = 17.44 x 15.88 µm)]; holotrichous a-isorhizas [n=10; 6.8–7.8 x 3.9 µm (mean = 6.96 x 3.9 µm)]; holotrichous A-isorhizas [n=10; 16.6– 20.5 x 9.8–11.7 µm (mean = 19.01 x 10.48 µm)]; heterotrichous microbasic rhopaloids [n=10; 10.7–11.7 x 5.8–6.8 µm (mean = 11.17 x 6.56 µm)]; Specimen MZUSP 1473, medusa tentacles with holotrichous Oisorhizas [n=10; 14.7–21.5 x 13.7–18.6 µm (mean = 18.91 x 16.46 µm)]; holotrichous a-isorhizas [n=10; 7.8– 9.8 x 3.9–4.9 µm (mean = 8.72 x 4.21 µm)]; holotrichous A-isorhizas [n=10; 19.6–21.5 x 9.8–11.7 µm (mean = 20.68 x 11.17 µm)]; heterotrichous microbasic rhopaloids [n=10; 12.7–14.7 x 5.8–7.8 µm (mean = 13.43 x 7.15 µm)]; Specimen MZUSP 1474, medusa tentacles with holotrichous O-isorhizas [n=10; 14.7–18.6 x 12.7–16.6 µm (mean = 17.15 x 14.90 µm)]; holotrichous a-isorhizas [n=10; 7.8–8.8 x 3.9–4.9 µm (mean = 7,94 x 4.31 µm)]; holotrichous A-isorhizas [n=10; 18.6–22.5 x 9.8–10.7 µm (mean = 19.90 x 9.90 µm)]; heterotrichous microbasic rhopaloids [n=10; 10.7–13.7 x 5.8–7.8 µm (mean = 11.76 x 6.66 µm)]; Specimen MZUSP 1475, medusa tentacles with holotrichous O-isorhizas [n=10; 15.6–18.6 x 14.7–16.6 µm (mean = 17.15 x 15.09 µm)]; holotrichous a-isorhizas [n=10; 6.8–8.8 x 3.9–4.9 µm (mean = 8.23 x 4.70 µm)]; holotrichous A-isorhizas [n=10; 19.6–21.6 x 10.7–14.7 µm (mean = 20.19 x 13.13 µm)]; heterotrichous microbasic rhopaloids [n=10; 11.7–14.7 x 6.8–7.8 µm (mean = 13.43 x 7.45 µm)]; Specimen MZUSP 1476, medusa tentacles with holotrichous O-isorhizas [n=10; 14.7–19.6 x 13.7–17.6 µm (mean = 18.03 x 16.07 µm)]; holotrichous a-isorhizas [n=10; 6.8–8.8 x 3.9–4.9 µm (mean = 8.13 x 4.50 µm)]; holotrichous A-isorhizas [n=10; 14.7–20.5 x 9.8–14.7 µm (mean = 18.03 x 12.05 µm)]; heterotrichous microbasic rhopaloids [n=10; 10.7–12.7 x 5.8–7.8 µm (mean = 11.37 x 6.86 µm)]; Specimen MZUSP 1477, medusa tentacles with holotrichous O-isorhizas [n=10; 14.7–21.5 x 12.7–18.6 µm (mean = 16.76 x 14.80 µm)]; holotrichous a-isorhizas [n=10; 7.8–9.8 x 3.9–4.9 µm (mean = 8.52 x 4.70 µm)]; holotrichous A-isorhizas [n=10; 14.7–18.6 x 7.8–10.7 µm (mean = 16.95 x 9.41 µm)]; heterotrichous microbasic rhopaloids [n=10; 12.7–13.7 x 6.8–7.8 µm (mean = 13.13 x 7.15 µm)]; Specimen USNM 53753, medusa tentacles with holotrichous O-isorhizas [n=10; 15.6–19.6 x 14.7–16.6 µm (mean = 18.91 x 15.88 µm)]; holotrichous a-isorhizas [n=10; 5.8–6.8 x 2.9 µm (mean = 5.97 x 2.9 µm)]; holotrichous A-isorhizas [n=10; 21.5–24.5 x 9.8–14.7 µm (mean = 23.13 x 13.23 µm)]; heterotrichous microbasic rhopaloids [n=10; 11.7–12.7 x 6.8 µm (mean = 12.35 x 6.8 µm)]; Specimen USNM 54437, medusa tentacles with holotrichous O-isorhizas [n=10; 19.6–23.5 x 17.6–19.6 µm (mean = 21.27 x 19.11 µm)]; holotrichous a-isorhizas [n=10; 5.8–7.8 x 2.9–3.9 µm (mean = 7.54 x 3.43 µm)]; holotrichous A-isorhizas [n=10; 21.5–25.4 x 15.6–17.6 µm (mean = 24.01 x 16.66 µm)]; heterotrichous microbasic rhopaloids [n=10; 10.7–12.7 x 5.8–6.8 µm (mean = 11.95 x 6.56 µm)]; Specimen USNM 54441, medusa tentacles with holotrichous O-isorhizas [n=10; 16.6–19.6 x 14.7–16.7 µm (mean = 17.44 x 15.68 µm)]; holotrichous a-isorhizas [n=10; 5.8–6.8 x 2.9–3.9 µm (mean = 6.56 x 3.43 µm)]; holotrichous A-isorhizas [n=10; 16.6–19.6 x 9.8–12.7 µm (mean = 18.42 x 10.48 µm)]; heterotrichous microbasic rhopaloids [n=10; 10.7–13.7 x 6.8 µm (mean = 12.15 x 6.8 µm)].

Systematic remarks. Some individuals remain in the three-tentacle-per-octant stage for the whole adult life span. The majority of the specimens collected in estuarine areas of São Paulo State ( Brazil) had three tentacles per octant (only 7 out of 175 specimens from estuarine areas had more than three tentacles per octant – see Appendix of Morandini et al. 2006a). Chrysaora lactea may have up to five tentacles per octant, a character shared with other species of the genus. However, the development of these tentacles is unique, determined by the formula 2-3-1-3-2 (see redescription in Morandini et al. 2006a). The species has been recorded earlier from the Caribbean region ( Agassiz & Mayer 1898), and the proximity with the five-tentacled C. quinquecirrha may generate doubts about the identification of these specimens. In a recent molecular study, Bayha (2006a; b) stated that specimens of Chrysaora from the Gulf of Mexico and Caribbean waters are different from C. lactea , and he called these specimens Chrysaora sp. #1. All specimens observed in USNM collections from areas of Belize (USNM 54923, 54924), Gulf of Mexico (Florida and Louisiana, USA, USNM 49733, 53826), Jamaica (USNM 53753), Panama (USNM 56653, 1073337), Puerto Rico (USNM 54437, 54438, 54439, 54441) and Virgin Islands (USNM 54440) agree with the tentacle development pattern observed for C. lactea . There is no morphological distinction between Brazilian and Argentinean specimens of C. lactea , and the Caribbean and Gulf of Mexico medusae of Chrysaora observed in the USNM. Thus, we conclude that the species has a continuous distribution from the Gulf of Mexico and Caribbean Sea southwards to the northern waters of Argentina. Contrary to the wide distribution of C. lactea proposed here, Bayha (2006a, b) concluded from genetic data that Chrysaora specimens in the Caribbean region are a distinct species. Further studies are warranted to clarify the taxonomy of these medusae.

Biological data. One-tentacled medusa: in laboratory cultures, development of the first tentacles occurs when ephyrae are 0.3–0.4 cm wide, reaching up to 2 cm bell diameter. Three-tentacled medusa: specimens from nature, 1.3 cm in diameter, already had the buds of secondary tentacles. In laboratory cultures, development of the secondary tentacles occurs in ephyrae 2–6 months after release from the strobila, when ephyrae range from 2.5–6 cm wide. Five-tentacled medusa: some specimens already have the maximum number of tentacles (40), apparently not related to size or maturity (one specimen 10 cm in diameter already had 5 tentacles in every octant). The final pattern of arrangement of marginal tentacles in each octant is: a single long median, primary tentacle, then next to the rhopalia (edge of the gastric pouches) two secondary tentacles similar in size, and between primary and secondary tentacles are tertiary on each side, typically smaller. The development of the tertiary tentacles in the species occurs in the subumbrellar portion of the lappet between the primary and secondary tentacles, thus they develop on the subumbrella and the single lappet gradually ruptures to “be converted into” two separate lappets. In a few specimens, averaging 6–11 cm in bell diameter, 6–7 tentacles per octant were noted (see statistical analysis below). The beginnings of the gonads appear in specimens from 4.5 to 6 cm in diameter. Maturation, i.e. gonadal development, is not directly proportional to observed size, as well as maximum tentacle number per octant. The life-cycle was described by Morandini et al. (2004).

Statystical analysis. The Pearson correlation coefficient was calculated to check the linear dependence of size and number of tentacles per octant in specimens from coastal and estuarine waters. Pearson correlation coefficient (size x number of tentacles) value for coastal specimens (n = 23) is 0.346 with a p value of 0.106, while that for estuarine specimens (n = 54) is 0.310 with a p value of 0.022. These data show that there is medium correlation between size and number of tentacles per octant. Additionally, we calculated the Pearson correlation coefficient for numbers of tentacles per octant in medusae of the same size (n = 21) but from different collecting locales (coastal and estuarine waters), resulting in a value of -0.067 with a p value of 0.774. Here we can state that there is little correlation between the data. Thus, based on our data there is a medium correlation between medusa size and tentacle number, but no direct correlation between specimens of the same size from different locations (estuarine and coastal waters) and number of tentacles.

Etymology. lactea : from the whitish colouration of some specimens, derived from the Greek lacteus (= milky) ( Eschscholtz 1829; Brown 1956).