查看更多>>摘要：Based on material collected during the BIOICE project, the taxonomy and distribution of Terebellides (Polychaeta; Trichobranchidae) in Icelandic waters is presented. Terebellides stroemii Sars, 1853 and Terebellides gracilis Malm, 1874 (as Terebellides williamsae Jirkov, 1989) were previously reported from the area. Terebellides atlantis Williams, 1984 is reported for the first time after the original description and redescribed. Terebellides bigeniculatus sp. nov. is diagnosed by the presence of twothoracic chaetigers with geniculate chaetae. Terebellides williamsae Jirkov, 1989 is proposed as a junior synonym of T. gracilis, whose holotype is redescribed herein. Several body characters with high taxonomic value in Terebellides are reviewed underthe SEM; additions to the diagnosis and new potential characters for a future taxonomic revision and phylogenetic study of the genus are also suggested. The geographical and bathymetric distribution of each species in relation to the GIF Ridge is discussed, and a key to Terebellides species from North East Atlantic waters is provided.
查看更多>>摘要：Clypeaster is a speciose echinoid genus with almost 50 extant and approximately 350 extinct species, encompassing a great heterogeneity of form. While some attempts to subdivide this genus have been made, none has gained widespread support, and all recent taxonomic treatments have left the genus intact. Here we report new data on internal buttress arrangement, determined from X-Ray tomography, and plate architecture, and use this to establish relationships amongst 19 extant species encompassing 8 ofthe 10 nominal subgenera that have been proposed. A cladistic analysis of these characters allows us to test the validity of previously suggested subgenera of Clypeaster. Our analysis confirms that Clypeaster is monophyletic with the clypeasteroid familyArachnoididae (as represented by Arachnoides and Ammotrophus) as its immediate sister-group. It also identifies Orihanihus as the most primitive subgenus in the family Clypeaster. However, none of the previously proposed subdivisions of Clypeaster wererecovered as clades and test architecture proves too ho-moplasous to allow a confident basis on which to subdivide the genus.
查看更多>>摘要：In this paper, M. yanomami n. sp., from Brazilian Amazonia, Chaetacis bandeirdnte n. sp., from Central Brazil, and the males of M. gaujoni Simon, 1897 and M. ruschii (Mello-Leitao, 1945) n. comb., respectively from Ecuador and Brazil, are described and illustrated for the first time. An ontogenetic series of the last development stages of both sexes of Micrathena excavata (C. L. Koch, 1836) is illustrated and briefly described. Adult females are larger and have longer legs and larger abdomens than adult males. Probably females undergo at least one additional moult before adulthood, compared to males. Micrathena ornata Mello-Leitao, 1932 is considered a junior synonym of M. plana (C. L. Koch, 1836), and M. mastonota Mello-Leitao 1940 is synonymized with M. horrida (Taczanowski, 1873). Acrosoma ruschii Mello-Leitao, 1945 is revalidated, transferred to Micrathena and considered a senior synonym of M. cicuta Gonzaga & Santos, 2004. Chaetacis necopinata (Chickering, 1960) is recorded for Brazil for thefirst time. Chaetacis incisa (Walckenaer, 1841) is considered a nomen dubium.
查看更多>>摘要：A new species of sponge-associated pontoniine shrimp from the northeastern Red Sea is described and illustrated. The new species is closely related to Periclimenaeus rhodope, but can be easily distinguished from the latter by the dense spinulation ofthe second pereiopod chelae. The new species is placed in the Periclimenaeus robustus species group, on account of the presence of the anterodorsal median lobe on the first abdominal segment. The new species is the first representative of the genus reported from a discrete Red Sea locality.
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