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Durante la realización de la expedición alemana LAMPOS a los archipiélagos del Arco de Scotia, en abril de 2002, se dragaron dos zooarios fustriformes negruscos de más de 10 cm de alto. Su estructura es tanto buguloide como fustroide, sus grandes ovicelas y su carencia de avicularias permiten describirlos como un nuevo género y una nueva especie.
Palabras clave: Bryozoa, Buguloidea, Flustra, Xenofustra voigti n. gen., n. sp., Atlántico sudoccidental, Arco de Scotia.
ABSTRACT
During the German LAMPOS cruises on April 2002, from the Arc of Scotia Archipelagos, two large (10-15 cm high) dark fustrine zoaria were collected. These turned out to be a new genus and a new species. Zoaria were slightly calcifed and had no avicularia. In its general structure this genus and species deserve a taxonomic place into the Bugulidean Cheilostomatida.
Key words: Bryozoa, Bugoloidea, Flustra, Xenofustra voigti n. gen, n. sp., South western Atlantic ocean, Scotia Arc archipelagos.
INTRODUCTION
Flustrine, Scruparine, Cellularine, Buguline and Cellariinie bryozoans represent a large set of fexible species that form an important part of the bryozoan faunas inhabiting subantarctic and An-tarctic waters (Hasting 1943, Moyano 1991, 1995, Hayward 1995). In antarctic waters until 1995 were recorded 264 cheilostomatous bryozoan species (Hayward 1995) from which not less than 82 (31%) exhibit fexible forms. This figure is actually higher due to the existence of fustrine fexible species like Adelascopora secunda, A. jeqolqa (Microporellidae) and Kymella polaris (Hippoporinidae) that have evol-ved from families or genera, with normally rigid and encrusting zoaria, to become fustriform species. On the other hand, in subantarctic Atlantic and Pacific waters off the southern tip of South America and in Kerguelen waters of the Indian Ocean have been recorded not less than 50 species having fexible zoaria out of > 200 bryozoan species in those areas (Hastings 1943, d’Hondt & Redier 1977, Moyano 1982, 1991) including Flustrapora magellanica (Microporidae).
Since 1980 several new records of known or unknown fexible species have been added. Among these standed up those described by López-Gappa (1982). This author proposed two new genera and three new species: Neofustra dimorphica, Austrofustra australis and A. gerlachi, all recorded in subantarctic waters.
Hayward (1995) added the new species Chartella notialis belonging to a genus previously unknown in subantarctic areas. Moyano (1998) in-troduced the new name Isoseculifustra rubefacta for an antarctic fustrine species having wide reddish zoaria erroneously atributed to Isoseculifustra an-gusta (Kluge) also an antarctic species with slender and yellowish zoaria living in deeper waters. Later on, samples taken in the continental slope near Cape Horn yielded 18 fexible species out of 56 (Moyano 2000).
Among these stand up tiny fexible cribri-morphan zoaria belonging to the new family Polliciporidae and to the new genus and species Pollicipora fucata Moyano 2000. Other interesting fnding was Adelascopora stellifera, the first subantarctic extant member of the fustrine microporellidan genus Adelascopora.
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Ten years ago, on April 2002, the German R/S Polarstern gathered a large collection of bottom samples containing bryozoans during the "LAMPOS" Polarstern Cruises to the Scotia Arc archipelagos which, starting and ending in Punta Arenas (Chile), reached the South Shetland Islands. A preliminary observation and analysis of the bryozoan samples revealed an abundant and speciose "fustran" fauna containing a clear cut separated subantarctic and Antarctic species.
The aim of this paper is to describe, illus-trate and discuss specimens of fustrine deep blue or black zoaria showing a mixing of zoarial and zooidal characters recalling genera like Flustra s.l. Himantozoum, Dendrobeania and Caulibugula.
MATERIALS AND METHODS
The material studied consist of two large (16-17 cm high) and one small (10 cm high) colonies obtained by the R/S vessel Polarstern during the "LAMPOS" Polastern Cruises to the Scotia Arc archipelagos in the following stations:
2) PS61/153-106.04.0218:12; 54° 33,23’ S; 56° 10,12’ W, 296,8 m; bottom trawl. Burdwood Bank (off South Falkland Islands)
Colonies were initially fxed in ethanol 96% but later on were kept in 70% ethanol.
SEM microphotographies were taken from gold-coated dried specimens previously washed with a very diluted NaClO solution.
RESULTS
Xenofustra n. gen.
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Diagnosis: Zoarium fustrine, light-calcifed, fexible, alga-like, unilaminar, profusely branched and fxed to substrate by means of a rhizoodial tuft. Zooids forming alternating rows in wich each zooid originates from a forked proximal basal part and ends in a distal partially free distal ascending part; distal and lateral zoecial borders provided with non-articulated spines. No avicularia. Ovicel hyperstomial, symmetrical not a kenozooid, well developed, with a calcifed entooecium.
Type species. Xenofustra voigti sp. n.
Etymology: Genus: From the Greek xenos meaning rare, strange and from the genus Flustra due to its zoarial structure; the species name after the oustanding German Bryozoologist the late Dr. Professor Ehrhard Voigt (Hamburg)
Xenofustra voigti n. sp.
Diagnosis: Zoarium fexible. Flustrine, dichotomously and densely ramifed, rami long and narrow, unilaminated, pluriserial, having from five to nine longitudinal zooecial rows between bifurcations; color dark brown in ethanol (96%) and lighter in ethilic alcohol (70%). Autozooids longer tan wide, ending in 4 disto-lateral tiny spines, with 5 – 10 sub marginal external unarticulate acute lateral spines and a wide and membranous operculum; each zooid with a partially free distal end overlaping the distal zooid. No avicularia. Ovicell hyperstomial, almost spherical, closed by the zooidal operculum, provided with 4 spines larger and thicker tan those of ordinary zooids.
Types: As indicated in materials and methods, deposited in Museo de Zoología de la Universidad de Concepción MZUC-UCCC.
Holotype: 35465
Paratype: 35466.
Fig. 1. (above-left) x 15. Zoarial bifurcation in frontal view showing ovicells and marginal spines Fig. 2. (above right) x 30 Central frontal part of fig 1. Note the marginal and ovicellar spines. ]]>
Fig. 3. (middle left) x 60 Lateral view of a zoarium showing the two types of spines. Fig. 4. (middle right) x 95 Frontal view of an ovicell exhibiting the frontal-proximal shield both types of spines. Fig. 5. (bottom left) x 15 Abfrontal view of fig. 1. Note limits between elongated zooids. Fig. 6. (bottom right) x 20 basal view of one zooid.
REMARKS
At first glance this species looks like a fustra having narrow and thick branches. A closer examination reveals the existence of long zooids having marginal and well spaciated and upright directed marginal spines recalling some beaniids. Ovicells recall those in Scrupocellariidae and other cellularine families. The structure of zooids in having a free distal end mimics Beania zooids and also in having marginal not articulated spines, but Beania lacks conspicous hiperstomial ovicells. Similar characters appear in some species of the Bugulinidae genus Camptoplites, however, in it avicularia are abundant and complex whereas they are completely lacking in Xenofustra gen. nov. In summary, Xenofustra voigti is provisionally put into the Bugulidae although lacking avicularia, but it is worth to remember that in some Bugula species like B. longissima Busk and B. neritina Linnaeus, avicularia are altogether wanting.
ACKNOWLEDGEMENTS
The author is indebted to the Alfred Wegener Institut that organized the LAMPOS cruises on board the R/V "Polarstern" making posible the study of a bryozoan collection from the Scotia Arc archipelagos. The author is also grateful for the help of Michael Schrödl of the Zoologische Staatssammlung München, and Maritza Palma former postgraduate student at Universidad de Concepción, Chile, researchers who were on board and physically sorted out the samples studied. Finally the author thanks the anonymous referees and the editors of this volumen for improving the form and contents of this work.
LITERATURE CITED
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Hayward, P. J. 1995. Antarctic Cheilostomatous Bryozoa. Oxford University Press Inc. New York [ Links ]
Hondt, J. L. d’ 1990. Adelascopora secunda subsp charcoti, subsp. Nov., nouveau bryozoaire cheilostome (Microporellidae) de l’océan glacial arctique. Bulletin de la Société zoologique de France (Francia), 115 (3): 263-270
Hondt, J. L. d’ & L. Redier 1977. Bryozoaires récoltés lors des campagnes d’été 1972 et 1974 aux ìles Kerguelen (Ctenpstomes, Cheilostomes sauf Cribrimorphes), Entoproctes). Comité National Français des Recherches Antarctiques, 42: 215-236
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Moyano G. H. I. 2002. Bryozoa from oceanic south eastern Pacific Island: Diversity and Zoogeography: 229-238. In: P. N. Wyse Jacson, C. Buttler & M. Spencer Jones (eds.) Bryozoan Studies 2001, Swets & Zellinger, Lisse, Netherlands [ Links ]
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Correspondencia a: 1 Departamento de Zoología, Universidad de Concepción. hugomoyan@gmail.com, Casilla 160-C, Concepción, Chile.
