Genus

About: Genus is a research topic. Over the lifetime, 68921 publications have been published within this topic receiving 590966 citations. The topic is also known as: monospecies genus & genus (zoology).

Fukuyoa paulensis gen. et sp. nov., a New Genus for the Globular Species of the Dinoflagellate Gambierdiscus (Dinophyceae)

Abstract: The marine epiphytic dinoflagellate Gambierdiscus is a toxicologically important genus responsible for ciguatera fish poisoning, the principal cause of non-bacterial illness associated with fish consumption. The genus currently contains species exhibiting either globular or anterior-posteriorly compressed morphologies with marked differences in cell shape and plate arrangement. Here we report a third globular, epiphytic and tychoplanktonic species from the coasts of Ubatuba, Brazil. The new species can be distinguished from G. yasumotoi and G. ruetzleri by its broader first apical plate that occupies a larger portion of the epitheca. Accordingly, phylogenetic trees from small subunit (SSU) and large subunit (LSU) ribosomal DNA sequences also showed strongly supported separation of the new species from the G. yasumotoi / G. ruetzleri group albeit with short distance. The molecular phylogenies, which included new sequences of the planktonic species Goniodoma polyedricum, further indicated that the globular species of Gambierdiscus formed a tight clade, clearly separated (with strong bootstrap support) from the clade of lenticular species including the type for Gambierdiscus. The morphological and molecular data in concert support the split of Gambierdiscus sensu lato into two genera. Gambierdiscus sensu stricto should be reserved for the species with lenticular shapes, highly compressed anterioposteriorly, with short-shank fishhook apical pore plate, large 2' plate, low and ascending cingular displacement, and pouch-like sulcal morphology. The new genus name Fukuyoa gen. nov. should be applied to the globular species, slightly laterally compressed, with long-shank fishhook apical pore plate, large 1' plate, greater and descending cingular displacement, and not pouch-like vertically-oriented sulcal morphology. Fukuyoa contains the new species Fukuyoa paulensis gen. et sp. nov., and F. yasumotoi comb. nov. and F. ruetzleri comb. nov.

Nuevas especies de Arachís (Leguminosae) de Brasil, Paraguay y Bolivia

Abstract: Eleven new species of Arachi s L. (Leguminosae) are described, representing seven of the nine taxonomic sections of the genus. Eight of the new species were referred to, and classified, in the monograph of Krapovickas and Gregory, but are now treated with their own specific epithet; one species had been collected before 1994, but the material was in sufficient doubt to not be mentioned in the Monograph, and two species were collected after that monograph was submitted for publication. The description of these eleven species will help clarify the systematics of the genus Arachi s , as well as aid in our understanding of the evolutionary path of certain important materials. Some of these may have played a role in developments which lead to the origin of the cultivated peanut

Piscivorous gastropods of the genus conus.

Abstract: Many marine snails are known to feed saprophytically on dead fishes.1' 2 The observations reported here are believed to represent the first known instances of the attacking, killing, and eating of live fishes by gastropod mollusks. It will also be shown that live fishes are the dominant and apparently exclusive food of one, and probably both, species of Conus to be discussed. This paper thus reports on an ecological niche not previously known to be occupied by gastropods. Feeding Mechanism.-Members of the family Conidae (Prosobranchiata: Stenoglossa) are predacious and feed by injecting a venom into the prey organism with a detachable, dartlike radula tooth (Fig. 1). There are but few reports of the observation of this process in the living animal. Most of our knowledge has been gained from anatomical studies of fixed specimens3 and from accounts of human injuries inflicted-by these snails.4 A more complete account of the feeding process, based on current studies of the ecology of the group, will be published elsewhere. Food in Nature.-Fish remains were first discovered in the alimentary tract of a specimen of Conus striatus L. from Hawaii dissected by Kondo.4 Additional fish remains were found in several specimens of this species from Hawaii and Guam dissected by the present author.' In each case, however, remains were insufficient to permit identification of the fishes, even to family. No other types of prey organism were found in alimentary tracts of C. striatus. No previous reports are known of fish remains in C. catus Bruguiere. Examination of alimentary tracts of twenty specimens of this species collected by the author in Hawaii revealed bones, otoliths, scales, and other remains of fishes in nine. The alimentary tract of one contained a discharged radula tooth, and those of the remaining ten specimens were empty. Three of the fishes were identified as the blenny Istiblennius gibbifrons Quoy and Gaimard. Two others are probably Bathygobius fuscus RUppell. The remains of four were insufficient to permit identification. Feeding of C. striatus in the Laboratory.-Specimens of C. striatus have been fed Kuhlia sandvicensis Steindachner, I. gibbifrons Quoy and Gaimard, and Entomacrodus mzarmoratus Bennett in the laboratory.