Hydroids (Cnidaria, Hydrozoa) of the Danish expedition to

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144 identical and they agree with the current concept of T. nutricula (see Schuchert 1996), there still remains the possibility of sibling hydroid species producing different adult medusae. According to Kramp (1961, 1968), there are only two valid Turritopsis medusae, T. nutricula and T. lata von Lendenfeld, 1885. Results from ongoing research (P. Schuchert, publication in prep.), however, suggest that Turritopsis medusae from various populations differ significantly and that T. nutricula as presently conceived is very likely a species complex. The Indonesian material was therefore only tentatively assigned to T. nutricula, pending further information on the medusa phase of this population. The Turritopsis species of the tropical Indo-Pacific might all be referrable to Turritopsis chevalense (Thorneley, 1904), a hydroid known from Ceylon. Turritopsis chevalense is only known from its polyp phase and at present not distinguishable from other Turritopsis hydroids. Distribution Circumglobal, mainly in tropical waters but spreading into temperate waters too. Type locality: Charleston Harbour, South Carolina, USA. Corydendrium cf. corrugatum Nutting, 1905 Fig. 5. Corydendrium corrugatum Nutting, 1905: 941, pl. 2: fig. 2, pl. 7: figs 5–7. Material examined: Kei Islands Expedition stations 74. – 107. – For comparison: MHNG INVE 25127, Corydendrium parasiticum, Mediterranean, Naples, fertile males. Description Colonies up to 4 cm high, arising from tangled, tortuous stolons. Colonies polysiphonic, stout, branching irregularly, diameter of terminal branches (hydranth pedicels) about 0.4 mm. Perisarc thick, not regularly two-layered, slightly and irregularly corrugated or folded, ending abruptly below base of hydranths. Branches adnate for most of their length, then curving outwards, preferentially on one side of branch, free part about 1 mm. Contracted hydranths 1.5 mm long, with about 20 scattered filiform tentacles. Sporosacs not seen. P. SCHUCHERT Fig. 5. Corydendrium cf. corrugatum Nutting, 1905; station 107. Lateral view of part of stem, without hydranths. – Scale: 0.5 mm. Remarks Nutting’s (1905) Hawaiian material as well as the present material was infertile, thus the genus allocation must remain preliminary only. In view of this lack of knowledge of the gonosome, and also the relatively simple structure of this hydroid offering few reliable distinguishing characters, the identification must considered to be only tentative. The structure of the trophosome of the Indonesian specimens matched rather well the description and figures given by Nutting (1905) for C. corrugatum, except for the annulation of the terminal part of the cauli. These free, terminal parts were longer and had only irregular corrugations and not the broad, regular annulation depicted by Nutting (1905). Because perisarc annulation in hydroids is often highly dependent on environmental conditions, not too much weight should be placed on this difference. Compared to Mediterranean material of Corydendrium parasiticum (Linnaeus, 1767), a species forming similar colonies as C. corrugatum, the Indonesian Corydendrium is much more robust (thicker), the free terminal branches (hy-
HYDROIDS OF THE DANISH EXPEDITION TO THE KEI ISLANDS dranth pedicels) are shorter and they are preferentially on one side only, thus creating branches with an anterior and rear side, a trait typical for C. corrugatum. In C. parasiticum, the hydranths are primarily held sideways. Distribution Hawaii, ?Indonesia. Type localities: South of Oahu, 582 m, and northeast coast of Maui, 181 m (Nutting 1905). Family Bougainvilliidae Garveia clevelandensis Pennycuik, 1959 Fig. 6. Garveia clevelandensis Pennycuik, 1959: 166, pl. 2: figs 7– 9. Material examined: MHNG INVE 31975, harbour of Ambon, collected 1890 by M. Bedot and C. Pictet (see Pictet 1893), on hydroid labelled as S. vegae (correct id. is Dynamena crisioides, see below). Fig. 6. Garveia clevelandensis Pennycuik, 1959. A. Single shoot of a colony. B. Terminal portion with hydranth and sporosac. C. Sporosac with egg. – Scales: A = 0.5 mm; B = 0.2 mm; C = 0.1 mm. 145 Description Colonies growing on Dynamena crisioides, erect, branched up to second order, height reaching 4 mm. Stolons creeping, ramified. Stems evenly thick, monosiphonic, about 0.15 mm diameter, densely covered by fine silt particles, periderm ends below tentacles of hydranths as pseudohydrotheca, pseudohydrotheca not much dilated and not sheathing base of tentacles. Periderm thin, without regular annulations. Hydranth 0.25 mm long, with 8–14 tentacles (10 or 12 most frequently), tentacles in one whorl; hypostome prominent, conical. Gonophores arise on stem and branches, pear-shaped, up to 0.2 mm. Gonophores are sessile sporosacs without any radialor circular canals, spadix simple, females bearing a single egg, gonophore covered by thin periderm lamella. Development takes place within sporosac. Male gonophores unknown. Remarks The present material corresponds very well with the description and figures of Pennycuik (1959), only the diameter of the stem being greater in the present material. This is the second find of this species and also a new record for Indonesia. Garveia clevelandensis closely resembles Garveia franciscana (Torrey, 1902) in its finer structure, especially the monosiphonic colony and the sporosacs with one egg only (see Vervoort 1964 or Morri 1982 for a description of G. franciscana). Garveia franciscana differs only in forming much larger colonies (7–20 cm) and in preferring brackish waters. The dense covering with silt particles found in Garveia clevelandensis could be another difference of diagnostic value. Garveia nutans Wright, 1859 forms up to 2.5 cm high colonies that are usually polysiphonic, but fertile, monosiphonic colonies are possible (MHNG INVE 31852). Monosiphonic Garveia nutans can be distinguished from G. clevelandensis by their higher number of eggs per sporosac (6–10). Distribution Queensland, Moluccas (new record). Type locality: Cleveland, Queensland, Australia; on Dynamena crisioides growing on jetty piles.
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