Eudendrium caraiuru sp. n. Figures 1–19 Eudendrium glomeratum; Marques, 1993: 68 –75, pl. 3; 2001: 361–369, figs. 23–30; Migotto, 1996: 122; Rosso and Marques, 1997: 417; Oliveira et al., 2000: 519 –525; Migotto et al., 2001: 289, 294–296; 2002: 11. non Eudendrium glomeratum Picard, 1951. Type material. Holotype: Brazil: São Sebastião: Baleeiro Point, female colony, 08.iii.1988, formol, on rock, 3m, col. A.E. Migotto (MZUSP 0385; former ACM­SP029). Paratypes: Brazil: São Sebastião: Cigarras Beach: male colony, 15.vii.1988, formol, intertidal, col. A.E. Migotto (MZUSP 0388; former ACM­SP034); Pitangueiras Beach (north rocky shore): male colony, 24.x.1992, formol, on rock, intertidal, col. A.C. Marques (ROMIZ B1223; former ACM­SP162); Jarobá Point, Parque: male colony, 17.ix.1990, formol, on test panel, 2m, col. A.C. Marques (MZUSP 0394; former ACM­SP056); Baleeiro Point:; Baraqueçaba Beach: female colonies, 12.xii.2001, formol, on metallic structures, 7m, col. H.K. Boscolo (MZUSP 0372); Lage dos Moleques: female colony, 05.xii.1991, formol, on rock, 5m, col. A.C. Marques (MZUSP 0423; former ACM­SP114). Additional material. Brazil. Rio de Janeiro: Urca: colony without gonophores, ix.1990, leg. I. Zalmon (MZUSP 0375; former ACM­RJ008); Ubatuba: Lázaro Beach: colony without gonophores, 28.vii.1992, formol, on rock, intertidal, col. A.C. Marques (MZUSP 0427; former ACM­SP120); colony without gonophores, 28.vii.1992, formol, on rock, intertidal, col. A.C. Marques (MZUSP 0428; former ACM­SP121); Maranduba Beach: colony without gonophores, 30.vii.1992, formol, on rock, intertidal, col. A.C. Marques (MZUSP 0429; former ACM­SP123); São Sebastião: Pier Sul (Petrobrás): male colony, 18.vii.1990, formol, on Perna perna, 1m, col. J.C. de Freitas (ACM­SP064); Pitangueiras Beach (north rocky shore): colony without gonophores, 18.viii.1988, formol, 6m, col. A.E. Migotto (MZUSP 0458; former ACM­SP159); male colony, 03.iv.1992, formol, on Schizoporella, 3m, col. A.E. Migotto (MZUSP 0459; former ACM­SP161); Jarobá Point (23º49,654´S 45º25,366´W): colony without gonophores 17.viii.1990, formol, on test panel, 1m, col. A.C. Marques (MNRJ 2043; former ACM­SP044); colony without gonophores, 17.viii.1990, formol, on test panel, 1m, col. A.C. Marques (ROMIZ B1221; former ACM­SP045); colony without gonophores, 20.viii.1990, formol, on test panel, 2m, col. A.C. Marques (MNRJ 2044; former ACM­SP048); colony without gonophores, 20.viii.1990, formol, on test panel, 2m, col. A.C. Marques (MNRJ 2045; former ACM­ SP049); colony without gonophores, 20.viii.1990, formol, on test panel, 2m, col. A.C. Marques (ROMIZ B1222; former ACM­SP050); colony without gonophores, 15.ix.1990, formol, on rope, 2m, col. A.C. Marques (MZUSP 0392; former ACM­SP054); male colony, 15.ix.1990, formol, on rope, 2m, col. A.C. Marques (MZUSP 0393; former ACM­ SP055); colonies without gonophores, 22.i.2000, formol, on test panel, 1m, col. O.M.P. Oliveira (MZUSP 0368); female colonies, 22.i.2000, formol, on test panel, 1m, col. O.M.P. Oliveira (MZUSP 0369); colonies without gonophores, 25.i.2002, alcohol, on ropes, 1m, col. O.M.P. Oliveira (MZUSP 0370); Barequeçaba Point (23º49,979´S 45º25,843´W): colonies without gomophores, 12.xii.2001, formol, on metallic structures, 7m, col. H.K. Boscolo (MZUSP 0371); female colonies, 12.xii.2001, formol, on metallic structures, 7m, col. H.K. Boscolo (MZUSP 0372); Cananéia: Cardoso Island, costão do Pereirinha: colony without gonophores, 26.viii.1992, formol, on rock, intertidal, col. A.C. Marques (MZUSP 0447; former ACM­SP145). Diagnosis. Large euryteles with shaft:capsule proportion 3.0–3.6; in pads on hydranth body, spadix of female gonophores, and in a whorl of 16–25 around hypostome. Female blastostyles with reduced hypostome and tentacles. Etymology. From the Tupi native language “ cáraiurú ” (= powerful mouth), in reference to the presence of large euryteles on the hypostome. Description. Colonies dioecious, arborescent, up to 54 mm in height, main stems unfascicled. Hydrocauli arising from creeping hydrorhiza; branches many, more or less alternate, occurring over entire hydrocaulus, branches up to third order, in radiate planes or rarely more or less planar; pedicels arising from main stem or branches of first, second or third order. Perisarc of main stem strongly developed, dark brown, single tubes 0.40 mm in diameter, with scarce annulations, in sets of 3–8 rings. Branches with 3–7 rings at origin, 0.20–0.25 mm in diameter. Pedicels sometimes completely annulated, yellowish, ca. 0.10 mm in diameter. Hydranths 0.18–0.75 mm in height, 0.18–0.57 mm in diameter (measured in the body region just below the tentacles), orange in color, with a distinct groove in the aboral region; tentacles 23–34 in number, occurring in a whorl below hypostome. Some hydranths with reduced tentacles juxtaposed in two close whorls. Gonophores styloids, arising from body of hydranth. Immature styloids placed in a circle around body of hydranth. Male blastostyle orange, with 10–29 sporosacs, each sporosac 1–2 chambered, linked to blastostyle body by a stalk, with a very distinct spadix over its longitudinal axis, and a terminal tubercle on its apex; distal chamber 0.12–0.18 mm in diameter. Male blastostyles completely reduced over earlier stages of their development with pedicels corrugated throughout. Female gonophores orange, arising on partially reduced blastostyles with highly atrophied hypostome and degenerated tentacles. Immature eggs having a simple and curved spadix over a single egg. Blastostyle reducing completely during development or at maximum with 1–5 stumps (tentacles), and spadices shed. Mature oval eggs thickened by perisarc and linked directly to the wrinkled pedicel by short and shallow concave peduncles. Eggs 4–7 in number, 0.24–0.39 mm in diameter. Nematocysts of two categories, heterotrichous microbasic euryteles and heterotrichous macrobasic (or mesobasic) euryteles. Small microbasic euryteles (seen discharged), 6.1–8.0 X 2.9–3.9 m, L / W = 1: 2.05– 2.1, oval, abundant; distributed over hydranth body, hypostome, coenosarc, and tentacles. Large macrobasic euryteles (seen discharged), 18.7–22.7 X 7.1–9.3 m, L / W 1: 2.4– 2.6, bean shaped, common. Discharged shaft up to 60 m in length, 3.0–3.6 times length of capsule; undischarged shaft in 1.5 coils inside capsule; distributed on hydranth body sometimes forming pads to a continuous ring, up to 25 capsules on hypostome, coenosarc, terminal tubercle, and immature female spadix sometimes forming pads. Distribution. Brazil: Rio de Janeiro State: Rio de Janeiro (Marques, 2001); São Paulo: Ubatuba (Marques, 2001), São Sebastião (Oliveira et al., 2000; Marques, 2001), Cananéia (Marques, 2001).

Published as part of Marques, Antonio C. & Oliveira, Otto M. P., 2003, Eudendrium caraiuru sp. n. (Hydrozoa; Anthoathecata; Eudendriidae) from the southeastern coast of Brazil, pp. 1-12 in Zootaxa 307 on pages 3-6, DOI: 10.5281/zenodo.156612