Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  Bucephalidae
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Perumytilus purpuratus is an abundant bivalve located in the intertidal rocky zone of South America that has been considered as a key species of the ecosystem. There are few studies of the host-parasite relationship of this bivalve; thus, this research aims to analyse the spatial and temporal variation in the prevalence of trematodes in P. purpuratus. Bivalves were collected from three localities (El Tabo, Las Cruces and Montemar) of central Chile (33°S, 71°W) during different seasons of 2010. The bivalves were also collected every metre, from the lowest to the highest level of the intertidal rocky zone, to determine the parasite distribution within the localities. Three species of trematodes as sporocyst stages were found: Prosorhynchoides carvajali, Proctoeces sp. and an undetermined fellodistomid species. Of the 37,692 bivalve specimens collected, 2.68% were parasitised. The undetermined fellodistomid species was the most prevalent parasite observed (1.69%). There were little detected differences in the prevalence of some trematode species between seasons. The prevalence of P. carvajali varied between localities, being most prevalent at Montemar. The distribution of trematodes along the rocky zone within the localities was variable, with P. carvajali being more prevalent in the mid-lowest level of the intertidal zone and the undetermined fellodistomid species being more prevalent in the mid-highest level. Both the abundance of definitive hosts and the environmental conditions likely result in different levels of infection by trematodes in P. purpuratus between and within the localities.
Prosorhynchus australis Szidat, 1961 is redescribed based on specimens collected from Conger orbignianus Valenciennes, 1842 caught in waters off Mar del Plata (38°08'S, 57°32'W), Argentina. Twenty one out of 32 congers examined were parasitized by P. australis (prevalence 65.62%, mean intensity 22.8, range 1-122). A number of morphological features not included in the original description justified the redescription of the species, and a detailed description of genitalia is provided for the first time. The diagnostic features used in the original description to define the species were corroborated, even after the range of measurements was broadened. Therefore P. australis is a valid species, despite not being considered in the recent literature regarding descriptions of new species in the genus.
A new bucephalid species, Prosorhynchoides carvajali sp. nov. is described. This parasite was found in three marine fish, Auchenionchus microcirrhis (type-host), A. variolosus and Sicyases sanguineus (other-hosts), collected from the intertidal rocky zones of central Chile. P. carvajali sp. nov. is characterized by a pharynx in a post-equatorial position, a large cirrus sac length (half of the total worm length) and rounded caecum extending dorsally and anteriorly from pharynx. Although Prosorhynchoides carvajali sp. nov. closely resembles P. labiata; the latter has an elongated, narrow and inverted-U-shape caecum, contrasting to P. carvajali sp. nov. which has a larger rounded caecum, directed anteriorly. To our knowledge this is the first known report of Prosorhynchoides on the South American Pacific coast.
A study of type material of Bucephalopsis rioplatensis Szidat, 1970 from intestine of the flatfish, Catathyridium jenynsii (Günther, 1862) (as Achirus trichospilus Berg, 1895) from the Rio de la Plata, Buenos Aires Province, Argentina, revealed that the ranges and morphological variations originally reported by Szidat (1970) and ascribed to age of specimens, appear to be caused by pressure during fixation; although some of the variation reported may have been a result of difference in age. This study redescribes the species and placed it in the genus Prosorhynchoides Dollfus, 1929 as P. rioplatensis (Szidat, 1970) comb. nov.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.