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1.
The bucephalid digenean Prosorhynchoides gracilescens (Rudolphi, 1819) is a common intestinal parasite of the angler fish Lophius piscatorius in European marine waters. Detailed studies of new material collected off the coasts of both Marseilles and Corsica in the western Mediterranean, and comparison with museum material from the northern North-East Atlantic, indicated that the accepted concept of this species comprises two distinct taxa. The Mediterranean form occurs in relatively small numbers and has small eggs, a large rhynchus and a vitelline distribution that finishes well short of the rhynchus, whereas the NE Atlantic form, which comprises the majority of records, occurs often in large numbers, has larger eggs, a relatively smaller rhynchus and a vitelline distribution that tends to reach the rhynchus. Since the type-material is from the Mediterranean and resembles the Mediterranean form, there was little option but to consider the latter as P. gracilescens (sensu stricto) and to describe the NE Atlantic form as a new species, for which the name P. borealis n. sp. is coined to reflect its northerly distribution. Both species are described and figured in detail, and a table and illustration of the diagnostic features are presented. In addition, some discussion is included on the distribution of these two species and whether P. gracilescens (s. str.) might be a relict species, and on non-European records of P. gracilescens (sensu lato).  相似文献   

2.
The digenetic trematode Bucephalus anguillae n. sp. is described from the intestine of eel, Anguilla anguilla L., originating from a brackish water fish farm on the Italian coast of the Adriatic Sea. The new taxon is 1 of 12 Bucephalus species characterized by an anterior rhynchus surrounded by 7 tentacular appendages, each when fully protruded with 2 prongs. Scanning electron microscopy reveals, for the first time in a Bucephalus species, the crescent-shaped, unspined field located between the rhynchus and the dorsal tentacles. A comparison of B. anguillae n. sp. with 11 congeneric species revealed its remarkable similarity with B. polymorphus Baer, 1827; however, the new species has a larger cirrus sac, larger pharynx, vitelline gland fields not extending the level of pharynx, ovary located in the pharyngeal area rather than fairly posterior to pharynx, smaller testes, relatively wider rhynchus, and tegumental armature comprising slightly larger spines. Multivariate discriminant analyses confirmed a differentiation of B. anguillae from populations of B. polymorphus; the combination of 4 variables, namely cirrus sac length, pharynx width, cirrus sac width, and rhynchus width yielded a total separation of compared species.  相似文献   

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5.
Six species of digeneans, including three new host records, are described from the bogue Boops boops off the Spanish NE Atlantic and the Mediterranean coasts. The species involved are: Robphildollfusium martinezgomezi López-Román, Gijón-Botella, Kim & Vilca-Choque, 1992, Magnibursatus caudofilamentosa (Reimer, 1971) Gibson & K?ie, 1991, Lepocreadium album Stossich, 1890, Steringotrema pagelli (van Beneden, 1871) Odhner, 1911, Tetrochetus coryphaenae Yamaguti, 1934 and Stephanostomum euzeti Bartoli & Bray, 2004 (metacercaria). B. boops is a new host for 11 metazoan parasites (six digeneans, three acanthocephalans, one copepod and one isopod) recovered in this study. These are reported and incorporated into a complete checklist of the metazoan parasites of B. boops throughout its distributional range. It comprises summarised information for 67 species in 260 host-parasite records and includes the name of the parasite species, the locality of the host, and the author and date of the published record. The taxonomy is updated and annotations are made on the validity of the records and synonymies.  相似文献   

6.
A new species of Podocotyloides is described from Sillago bassensis caught off the coast of Western Australia. This is the second report of a species of this genus from Australian waters but the first of a new species. P. victori n. sp. is one of four species whose vitelline follicles extend into the forebody. It is distinguished from the other three species with vitelline follicles in the forebody by its relatively shorter forebody, smaller eggs and bipartite seminal vesicle. Pedunculotrema Fischthal & Thomas, 1970 is reduced to synonymy with Podocotyloides Yamaguti, 1934.  相似文献   

7.
Although the majority of onychophorans are viviparous or ovoviviparous, oviparity has been described in a number of species found exclusively in Australia and New Zealand. Light microscopy and scanning and transmission electron microscopy were used to examine developing eggs and the reproductive tract of the oviparous Planipapillus mundus. Deposited eggs and fully developed eggs dissected from the terminal end of the uteri have an outer thick, slightly opaque chorion, and an inner thin, transparent vitelline membrane. The chorion comprises an outermost extrachorion, sculptured with domes equally spaced over the surface; a middle exochorion, with pores occurring in a pattern of distribution equivalent to that of the domes of the extrachorion above; and an innermost, thick endochorion consisting of a spongelike reticulum of cavities comparable to the respiratory network found in insect eggs. The vitelline membrane lies beneath the chorion, from which it is separated by a fluid‐filled space. The vitelline membrane tightly invests the developing egg. Examination of oocytes in the ovary and developing eggs at various stages of passage through the uterus indicate that the majority of chorion deposition occurs in the midregion of the uterus, where vast networks of endoplasmic reticulum are present in the columnar epithelium. The vitelline membrane, however, is believed to begin its development as a primary egg membrane, surrounding the developing oocytes in the ovary. The vitelline membrane is transformed after fertilization, presumably by secretions from the anterior region of the uterus; hence, it should be more accurately referred to as a fertilization membrane. Aspects of the reproductive biology of P. mundus are also included. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.  相似文献   

8.
The Strait of Gibraltar has been proposed to be the divide between two marine biogeographical regions, the Mediterranean Sea and the Northeast Atlantic. Intraspecific studies have shown, for several of the examined species, a reduction of gene flow between the two basins. The present study examines genetic variation at nuclear and mitochondrial loci in five marine teleost species belonging to the family Sparidae. Four samples for each species were analysed spanning the Northeast Atlantic and the Mediterranean. For all individuals 17 allozyme loci were scored and a combined single strand conformation polymorphism-sequencing approach was used to survey approximately 190 bp of the mitochondrial DNA (mtDNA) D-loop region. All five species share similar biological features. For three species, namely Lithognathus mormyrus, Spondyliosoma cantharus, and Dentex dentex, large mtDNA divergence was observed between Atlantic and Mediterranean samples. Little or no mtDNA differentiation was found in the other two species, Pagrus pagrus and Pagellus bogaraveo. Allozyme data revealed strong differentiation when comparing Atlantic and Mediterranean samples of L. mormyrus and D. dentex, moderate for P. pagrus, and no differentiation for P. bogaraveo and S. cantharus. These results provide evidence for a sharp phylogeographical break (sensu Avise) between the Atlantic and the Mediterranean for two (or possibly three) sparid species of the five investigated. At the same time, the obtained results for the other two species raise the question on which ecological/historical factors might have caused the observed discrepancy in the geographical distribution of genetic variation among otherwise biologically similar species.  相似文献   

9.
Four species of digeneans parasitic in the bogue Boops boops from the Spanish coast of the NE Atlantic are described. All are new records for this host, but one species is new and the other three are considered to be accidental parasites. Wardula bartolii n. sp. (Mesometridae) is distinguished from its two congeners on the basis of a range of morphometrical features, such as the post-ovarian extent of the uterus, the relative length of the attachment organ, the position of the pharynx and vitelline fields, and the absence of anterior caecal diverticula. The other three species are Lecithaster confusus Odhner, 1905, Aponurus laguncula Looss, 1907 (Lecithasteridae) and Accacladium serpentulum Odhner, 1928) (Accacoeliidae).  相似文献   

10.
Three new genera ( Araphura, Leptognathioides and Stenotanais ) and six new species of tanaid crustaceans from below 1000 m depth in the north-east Atlantic are described. Two of the new species belong to the genus Leptognathiella Hansen, 1913, which is redescribed and removed from synonymy with Leptognathia Sars, 1882 ( sensu Lang 1968). These species are relatively common in the tanaid material examined and have a widespread distribution in the area under study, i.e. the Rockall Trough, Porcupine Seabight and Bay of Biscay. All six species are found at depths between 2070 and 2892 m. A further nine species previously belonging to the genus Leptognathia are removed to the new genera or to Leptognathiella. New records of Leptognathioides polita (Hansen, 1913) comb.n. and Leptognathiella abyssi (Hansen, 1913) have been obtained.  相似文献   

11.
Grateloupia doryphora (Montagne) Howe, originally described from Peru, has repeatedly been reported as an invasive species in Atlantic and Mediterranean waters. Various attempts to explain this species' route of introduction have been unsatisfactory. New evidence from comparative rbcL sequence analysis and morphology suggests that this adventive species in the NE and NW Atlantic corresponds with G. turuturu Yamada, originally described from Japan. This provenance follows a well-recognized trend of invasive marine organisms that have colonized the Atlantic Ocean and Mediterranean Sea from Pacific NE Asia.  相似文献   

12.
The distribution of species is expressed by their occurrence in local faunal lists often compiled by non‐taxonomists. In the case of rare or cryptic species, this can pose a severe limitation on the validity and thus the application of the resulting biodiversity data. Here, we show an example of a shallow‐water echinoid to illustrate problematic distribution data based on misidentification. This species, Arbaciella elegans, was established on the basis of Central African material and later reported from various places in the Mediterranean and the Northern Atlantic. Morphological comparison with the type material casts considerable doubt on the validity of these records. Genetical characterization of material from the Azores clearly shows that the dark Arbaciella phenotype reported to the Mediterranean and north‐east Atlantic in fact represents juveniles of another species, namely Arbacia lixula.  相似文献   

13.
Alcicornis haroldi n. sp. is described from Carangoides fulvoguttatus from off New Caledonia, South Pacific. It differs from all other Alcicornis spp. in its large protuberant pharynx, and from the most similar species, A. baylisi Nagaty, 1937, in its broader rhynchus, indistinct withdrawn tentacles and vitelline distribution.  相似文献   

14.
Probothriocephalus alaini n. sp. is described from the intestine of the deep-sea fish Xenodermichthys copei (Gill) (Osmeriformes: Alepocephalidae) from the North Atlantic. It resembles most closely the type-species of Probothriocephalus, P. muelleri Campbell, 1977 described from Alepocephalus agassizi Goode & Bean (Alepocephalidae), but it differs in the distribution of the vitelline follicles that form two medially well-separated bands (versus almost circum-cortical in P. muelleri), in the shape of gravid proglottids that are elongate, much longer than wide (always wider than long in P. muelleri), in the size of the body (much larger in the latter species) and a somewhat different shape of the scolex (widely lanceolate versus elongate and tapering anteriorly in P. muelleri). Other congeneric species, described from deep-sea fish of different orders (Myctophiformes and Beryciformes), lack a distinct neck region, their eggs were reported to be non-operculate and they have much more pronounced external segmentation.  相似文献   

15.
Two new species of bucephalids (Digenea: Bucephalidae) were found parasitizing freshwater fishes of Argentina. Prosorhynchoides cambapuntaensis sp. n. from Salminus maxillosus (Characidae) is characterised by the tegument covered with two kinds of spines, scale-like spines anteriorly and fine spines posteriorly; uterine loops reaching the vitelline arch in the pre-oral region; and the Laurer's canal short, opening dorsally immediately posterior to the ovary. Rhipidocotyle santanaensis sp. n. from Acestrorhynchus pantaneiro (Acestrorhynchidae) is characterised by the rhynchus with two lateral projections; the testes arranged in tandem or slightly diagonal; and the vitelline follicles forming an arch in the pre-oral region.  相似文献   

16.
Previous studies on the common ragworm Hediste diversicolor (Polychaeta: Nereididae) revealed a marked genetic fragmentation across its distribution and the occurrence of sibling taxa in the Baltic Sea. These results suggested that the phylogeographic patterns of H. diversicolor could reflect interactions between cryptic differentiation and multiple colonization events. This study aims to describe the large-scale genetic structuring of H. diversicolor and to trace the phylogeographic origins of the genetic types described in the Baltic Sea. Samples of H. diversicolor (2 <  n  < 28) were collected at 16 locations across the NE Atlantic coasts of Europe and Morocco and in the Mediterranean, Black and Caspian Seas and sequenced at two mitochondrial gene fragments (COI and cyt b , 345 and 290 bp, respectively). Bayesian analyses revealed deep phylogeographic splits yielding three main clades corresponding to populations (i) from the NE Atlantic coasts (from Germany to Morocco) and from part of the Western Mediterranean, (ii) from the Mediterranean Sea, and (iii) from the Black and Caspian Seas. These clades are further divided in well-supported subclades including populations from different regions of NE Atlantic and Mediterranean (i.e. Portugal/Morocco, Western Mediterranean, Adriatic Sea). The Baltic Sea comprises three sympatric lineages sharing a common evolutionary history with populations from NE Atlantic, Western Mediterranean and Black/Caspian Seas, respectively. Hence, the current patterns of genetic structuring of H. diversicolor appear as the result of allopatric isolation, multiple colonization events and possible adaptation to local environmental conditions.  相似文献   

17.
The genus Adeonella Busk (1884) comprises 41 species, 15 of which are considered to be new to science. Adeonella lichenoides (Lamarck) is regarded as the senior synonym of A. platalea (Busk) (= A. polymorpha Busk), the type species of the genus. Adeonella is distributed throughout the Indo-West Pacific realm, the Mediterranean, and the South Atlantic Ocean. Its highest diversity is found off the east coasts of southern Africa. Thirty-one species (15 new to science) are described and illustrated, morphology and geographical distribution are discussed and a key is provided to all recognized species.  相似文献   

18.
A new species,Paralepidapedon williamsi, is described from the fishCottunculus microps and an unidentified fish of the suborder Cottoidei in the NE Atlantic Ocean. This species is the first member of the genus to be recognized in the Atlantic Ocean. Its general morphology is similar to that of the other members of the genus, but it is distinguished by its large eggs and the relatively few gland-cells associated with the external seminal vesicle. The genusParalepidapedon, which differs fromNeolepidapedon in the possession of a uroproct, is reviewed and a key to the species given. The genus is considered to include five species.  相似文献   

19.
Three cestode species are recorded from Podiceps auritus at Lake Myvatn, Iceland: Tatria minor Kowalewski, 1904 (Amabiliidae), Confluaria furcifera (Krabbe, 1869) and C. islandica n. sp. (Hymenolepididae). C. islandica n. sp. is described on the basis of specimens reported by Baer (1962) as 'Hymenolepis capillaris (Krabbe, 1869)' and newly-collected specimens. It is unique among Confluaria spp. in having: a muscular, thick-walled genital atrium with its proximal end divided into male and female canals; distinct microtriches covering the surface of the rhynchus; and a short, cylindrical cirrus. The shape and the total length of the rostellar hooks are most similar to those of C. capillaris (Rudolphi, 1810), but differ in having a long handle and a relatively small epiphyseal thickening rather than a short handle and the large epiphyseal thickening. The allopatry of the NE Atlantic population of P. auritus is believed to have been a prerequisite for the formation of its specific helminth fauna. Both C. furcifera and T. minor are recorded for the first time in Iceland.  相似文献   

20.
The distribution of Octopus vulgaris has not yet been completely clarified. For a long time, a cosmopolitan distribution with unknown distribution limits had been assumed. This assumption has recently been questioned and it has been postulated that the distribution is restricted to the Mediterranean and the northeastern Atlantic. However, as our previous studies show, the existence of O. vulgaris can be confirmed for the Mediterranean and the whole eastern Atlantic, and evidence is provided for its occurrence in the western Atlantic. The aim of the present work is to extend our previous data matrix and to clarify whether O. vulgaris exists in the northwestern Pacific. Therefore, the sequence variation in ostensible O. vulgaris from 13 localities in the Mediterranean (France), the Atlantic Ocean [Lanzarote, Senegal, South Africa (Atlantic, Indian Ocean), Tristan da Cunha, north, middle and south Brazil], the Caribbean Sea (Venezuela) and the Pacific Ocean (Taiwan, Japan and Costa Rica) was examined using the mitochondrial genes coding for the 16S rRNA and cytochrome oxidase subunit III (COIII). Sequence divergence was relatively low between populations of O. vulgaris from the Mediterranean, the eastern and western Atlantic (except north Brazil), Venezuela, Taiwan and Japan compared with other species of the genus Octopus . Trees constructed by using maximum likelihood, neighbour joining and maximum parsimony algorithms (PAUP) show the above-mentioned populations from the Mediterranean, the western and eastern Atlantic, Venezuela and the northwestern Pacific (Japan and Taiwan) as a monophyletic cluster. Thus, even if the Octopus vulgaris -like octopus from north Brazil should turn out a cryptic species, the data of this work not only support our hypothesis of the distribution of O. vulgaris in the Mediterranean, the eastern and western Atlantic but also show that O. vulgaris is present in the northwestern Pacific, namely in the waters of Taiwan and Japan.  相似文献   

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