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1.
The diversity, taxonomy and distribution of the Opheliidae (Annelida: Polychaeta) in Icelandic waters is reviewed based on material collected during the BIOICE project. Nine opheliid species are recorded from Iceland; of these, three were previously reported in the area (Ophelia limacina, Ophelina cylindricaudata and O. acuminata), four are new for Icelandic waters (Ammotrypanella cf. arctica, Ophelina abranchiata, O. helgolandica and Tachytrypane jeffreisii), and two are new to science. Ophelina basicirra sp. nov. is distinguished by having a narrow anal tube with one short proximal anal cirrus in ventral position. Ophelina bowitzi sp. nov. is characterized by the small size of its anterior branchiae, which become larger in the middle and posterior body regions, and by an upwardly bent anal tube that is wide at the base and narrowing distally. The genera Euzonus, Armandia and Polyophthalmus are not represented in the BIOICE samples. The distribution of each species off Iceland is presented; one species is restricted to shallow waters of northwestern fjords, three species are found south of the GIF Ridge, and five species are circumicelandic. Several body characters with taxonomic relevance in some species are reviewed based on SEM images. Furthermore, as a first step towards a future revision of the genus Ophelina Örsted 1843 in North Atlantic waters, the status of each species originally described or subsequently reported from the area is commented on, and a key to the currently valid species is presented. Ophelina longicephala Hartmann-Schröder, 1977, formerly a subspecies of O. delapidans (Kinberg, 1866), is raised to species status.  相似文献   

2.
Spatial patterns of intertidal peracarids, associated with the alga Corallina elongata, were studied along the whole Iberian Peninsula. A total of 28,215 specimens were collected, comprising 78 different species (57 amphipods, 16 isopods, 4 tanaids and 1 cumacean), most of them with Atlantic-Mediterranean distribution (60%) and only 9% of Mediterranean endemics. Gammarids were dominant in abundance and number of species, representing more than 70% of the total peracarids. The most common species collected during the present study were the caprellid Caprella penantis, the gammarids Hyale schmidti, Hyale stebbingi, Jassa cf. falcata and Stenothoe monoculoides, the isopod Ischyromene lacazei and the tanaid Tanais dulongii. Caprellids and tanaidaceans presented their highest populations in the stations of the Strait of Gibraltar, whereas isopods were more abundant in Atlantic stations. Univariate analyses did not reflected differences in number of species, abundance and Shannon-Weaver diversity between Mediterranean and Atlantic. However, cluster analyses and Whittaker index, as measure of ß-diversity, showed a different species composition between Mediterranean and Atlantic and a replacement of species along the coast, especially at the Strait of Gibraltar. The turnover mainly affected species of the same genera, probably related with sympatric speciation. CCA and BIO-ENV analyses showed high correlations between environmental measures (especially conductivity) and peracarid distribution. Mediterranean species tolerated higher values of conductivity and temperature, while Atlantic species were associated with stations characterized by higher oxygen concentrations.  相似文献   

3.
We document the presence of the bald ibis genus Geronticus Wagler, 1832 (Aves: Threskiornithidae) from the mid-Pliocene (ca. 3–3.5 Ma) of South Africa based on an incomplete skull from the Bolt’s Farm Cave System (Cradle of Humankind, Gauteng, South Africa). The fossil cranium is distinct on morphometric and structural grounds from Geronticus apelex, the only other Pliocene Geronticus described from Southern Africa, but is very close in dimensions and general morphology to the extant G. calvus of South Africa, and the Bolt’s Farm fossil ibis is therefore attributed to G. cf. calvus. Modern Geronticus ibises are localised to temperate, open grasslands and semi-arid steppe, and nest exclusively on cliffs and similar rocky eminences. Given its attribution as G. cf. calvus, the Bolt’s Farm ibis was likely similar in ecology to the extant G. calvus, suggesting that the habitat surrounding the Bolt’s Farm fossil site during the mid-Pliocene featured open grassland and presence of cliffs. This record constrains the divergence between G. calvus and its putative ancestor G. apelex to the mid-Pliocene and implies that G. calvus has possibly been subject to “evolutionary/morphological stasis” for more than 3 million years. This postulated stasis would be consistent with the notion that extant genera with few species (i.e. high genus-to-species ratios) show low rates of phenotypic diversification and change through the Neogene.  相似文献   

4.
Squids of the family Onychoteuthidae are ecologically important in pelagic food webs and have been reported from every ocean except the Arctic. Although they are abundant and caught frequently as bycatch in fisheries, the biogeography of many species remains poorly understood. Species identification within the Atlantic Ocean is usually restricted to two species: Onychoteuthis banksii and Onykia carriboea. Here, we report the occurrence of four species of the family Onychoteuthidae (Onychoteuthis cf. banksii, Onykia carriboea, Walvisteuthis jeremiahi, and Onychoteuthis sp. AL 2) from the Sargasso Sea in the western Atlantic, identified using DNA barcoding (cytochrome c oxidase subunit I) and morphology. Our results have doubled the known onychoteuthid biodiversity in the Sargasso Sea, which has implications for the ecology of this oceanic region.  相似文献   

5.
Six species that belong to the diatom genus Attheya were found in the Russian waters of the Sea of Japan. A. cf. flexuosa is a new record for the seas of Russia. A. decora is recorded for the first time for the Sea of Japan. The peculiarities of the morphology of A. decora and A. cf. flexuosa are described and illustrated. The study of the seasonal distribution, abundance, and ecology of Attheya species in the northwestern Sea of Japan showed that A. longicornis and A. ussurensis were the most numerous and widespread species, reaching maximum densities (up to 1.5 × 106 and 1.8 × 104 cells/liter, respectively) in the spring, summer, and fall. A. cf. flexuosa and A. septentrionalis were rare and were found in low numbers in the winter and early spring. Based on the ultrastructure of the girdle bands, the form and number of chloroplasts, the presence/absence of rimoportula on the valve, and habitat features, we distinguished two groups of species of the genus Attheya from the Sea of Japan. The first group includes psammophytes A. decora, A. arenicola, and A. ussurensis; the second one comprises A. longicornis and A. cf. flexuosa epiphytic on other diatoms, as well as A. septentrionalis, which is found in the under-ice plankton and is able to attach to the underside of ice.  相似文献   

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Based on light and scanning electron microscopical studies, a new nematode parasite, Pseudodelphis eleginopsis n. sp. (Dracunculoidea: Guyanemidae), is described from tissues behind the gills of the Patagonian blennie Eleginops maclovinus (Cuvier) (Perciformes: Eleginopsidae) off the Atlantic coast (San Matías and San José Gulfs) of Patagonia, Argentina. The new species is mainly characterised by the length of the body (males 10–13 mm, larvigerous females 31–59 mm), the number (14) and arrangement of cephalic papillae, the absence of a buccal capsule, the muscular to glandular oesophagus length ratio (1:3–4) of larvigerous females, the length of the spicules (48–63 µm) and the number (7 pairs) and arrangement of the caudal papillae in the male. Pseudodelphis eleginopsis n. sp. is the first species of this genus described from a marine fish in the Atlantic Ocean and the first known dracunculoid parasitising the fish host belonging to the family Eleginopsidae. As revealed by the examination of very young females of the new species, the female genital tract of Pseudodelphis spp. is monodelphic. The genus Syngnathinema Moravec, Spangenberg & Frasca, 2001 is considered a junior synonym of Pseudodelphis Adamson & Roth, 1990 and, consequently, S. californiense and S. chitwoodi are transferred to Pseudodelphis as P. californiensis (Moravec, Spangenberg & Frasca, 2001) n. comb. and P. chitwoodi (Moravec & Kuchta, 2013) n. comb., respectively. Two dracunculoid species, Pseudodelphis limnicola Brugni & Viozzi, 2006 and the previously established Philonema percichthydis Moravec, Urawa & Coria, 1997, both described from the same freshwater host species, Percichthys trucha (Valenciennes), in the same region (Patagonia), are considered to be identical; therefore, the valid name of this species is Pseudodelphis percichthydis n. comb. and P. limnicola becomes its junior synonym. A key to the species of Pseudodelphis is provided.  相似文献   

10.
Five species of mouse or forest shrews (Myosorex) are endemic to South Africa, Lesotho and Swaziland, four of which (Myosorex varius, Myosorex cafer, Myosorex longicaudatus and Myosorex cf. tenuis) are associated with montane or temperate grassland, fynbos and/or forest habitats while a fifth (Myosorex sclateri) is associated with lowland subtropical forests. Due to their small size, specialised habitat, low dispersal capacity, high metabolism and sensitivity to temperature extremes, we predicted that, particularly for montane species, future climate change should have a negative impact on area of occupancy (AOO) and ultimately extinction risks. Species distribution models (SDMs) indicated general declines in AOO of three species by 2050 under the A1b and A2 climate change scenarios (M. cafer, M. varius, M. longicaudatus) while two species (M. sclateri and M. cf. tenuis) remained unchanged (assuming no dispersal) or increased their AOO (assuming dispersal). While temperate species such as M. varius appear to be limited by temperature maxima (preferring cooler temperatures), the subtropical species M. sclateri appears to be limited by temperature minima (preferring warmer temperatures). Evidence for declines in AOO informed the uplisting (to a higher category of threat) of the Red List status of four Myosorex species to either vulnerable or endangered as part of a separate regional International Union for Conservation of Nature (IUCN) Red List assessment.  相似文献   

11.
Variability of microsatellite DNA loci Gmo3, Gmo34, and Gmo35 is studied in samples of Pacific cod Gadus macrocephalus and Atlantic cod G. morhua. The results show high values of identity of the samples within the North Pacific basin (0.9766–0.9924) and within the Northeast Atlantic basin (0.9580). Based on the pairwise assessment of genetic differentiation, the F ST values are significantly different in all variants between the samples of Pacific and Atlantic cod (F ST = 0.5235–0.6719, p < 0.001). Within the basins, the significant differences in the frequencies of main alleles are revealed in the loci Gmo3 and Gmo34 for the samples from the Pacific and Atlantic oceans, respectively.  相似文献   

12.
From the Bavarian Early/Middle Miocene (MN5) site Sandelzhausen, nine species of carnivoran mammals are identified including the hemicyonine ursid Hemicyon stehlini, the amphicyonids Amphicyon cf. major and Pseudarctos bavaricus, the mustelids Ischyrictis zibethoides and Martes cf. munki, the mephitid Proputorius pusillus, the viverrid Leptoplesictis cf. aurelianensis, the felid Pseudaelurus romieviensis, and finally the recently described barbourofelid Prosansanosmilus eggeri. With these taxa present, Sandelzhausen shows a carnivoran community typical, though deprived, for the Lower to Middle Miocene of Europe, but different from roughly contemporary Mediterranean faunas such as those from Çandir or Pa?alar in Turkey.  相似文献   

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The genus Leptodes was erected by Dejean (1834) for a single species, Sepidium boisduvalii Zubkoff, 1833, which is, consequently, the type species by monotypy. Kaszab (1959) established in Leptodes the subgenus Leptodinopsis based on the same type species, Sepidium boisduvalii. Thus the names Leptodes and Leptodinopsis are objective synonyms: Leptodes Dejean, 1834 = Leptodinopsis Kaszab, 1959, syn. n. A new subgenus Mesoleptodes G. Medvedev et Iljina subgen, n. (type species Leptodes semenowi Reitter, 1892) is established for species which Kaszab included in Leptodes s. str. A new species, Leptodes daghestanicus G. Medvedev et Iljina, sp. n., is described from Daghestan.  相似文献   

15.
The intraspecies variability of Spermophilus relictus sensu lato was studied based on 27 measurements of skulls from 67 specimens of relict ground squirrels (S. relictus) and 66 specimens of Tien Shan ground squirrels (S. ralli), as well as six specimens of the relict ground squirrel from the Gissar Ridge (Tien Shan). A colorimetric analysis of skins of relict ground squirrels (19 specimens, including three individuals from the Gissar Ridge) and Tien Shan ground squirrels (19 specimens) was made. Significant intraspecies variability was found in the relict and Issyk-Kul ground squirrels, whereas the interspecies differences were small, raising questions about the species independence of the Tien Shan ground squirrel (S. ralli).  相似文献   

16.
A parasitological study was performed of chars of the genus Salvelinus inhabiting Lake Kronotskoe (Kamchatka Peninsula)—S. malma, S. albus, S. schmidtii, and S. kronocius, as well as of juvenile Salvelinus spp. Twenty-three species of parasites, including six species new for the lake, Hennequya zschokkei, Protteocephalus longicollis, Diphyllobothrium dendriticum, Crepidostomum sp., Echinorhynchus salmonis, and Paracanthobdella livanowi, were found. With consideration of published data, in chars of this water body, 28 species of parasites were recorded, including seven species (N. cf. pungitius, B. luciopercae, Crepidostomum sp., Cr. fausti, Cr. cf. cooperi, Eubothrium crassium, and Proteocephalus sp.), whose presence or species identification in the lake ecosystem need confirmation. Two species (N. rutili and Diphyllobothrium sp.) are removed from the list. Parasites common for all species of chars were revealed. They include Myxobolus arcticus, E. salvelini, D. ditretum, Crepidostotum sp., Cr. farionis, Cr. metoecus, Cystidicola farionis, Cucullanus truttae, Philonema oncorhynchi, and Salmincola carpionis. Cluster analysis of the fauna of parasites of different species of chars demonstrated considerable differences in infestation, which indicates differences between them in preference for food items and occupied biotopes and thereby supports the ecological differentiation of chars in the basin of Lake Kronotskoe. S. albus and S. kronocius are most similar in parasitofauna, which is determined by their predation; S. malma as a benthophage is infected by the same species of parasites, but considerably less intensively. Extremely high indices of population numbers of some parasite species are considered as a manifestation of the Krebs cycle in parasites under the conditions of an isolated lake.  相似文献   

17.
Since their recent introductions into Florida waters, three sessile invertebrates [Perna viridis (Asian green mussel), Mytella charruana (charru mussel) and Megabalanus coccopoma (pink titan acorn barnacle)] have expanded their range along the Atlantic coast in estuarine waters. Little research has been done to understand how these nonnative species interact with the ecologically and economically important eastern oyster Crassostrea virginica. To assess the potential effects of P. viridis, M. charruana and M. coccopoma on C. virginica, the following questions were addressed in manipulative experiments. (1) Does the presence of nonnative species decrease oyster larval settlement? (2) Do oyster larvae avoid settling on nonnative species? (3) Do nonnative species decrease survival of juvenile oysters (spat)? (4) Do nonnative species hinder spat growth? We included two controls: absence of nonnative species and presence of the native mussel Geukensia demissa. The nonnative species influenced settlement, growth and survival of C. virginica in different ways. M. coccopoma and P. viridis negatively influenced larval settlement, whereas M. charruana had no influence on the total number of settled larvae. Oyster larvae avoided settling on all three nonnative species and the native G. demissa. Both nonnative mussels negatively affected survival of juvenile oysters but only M. charruana also reduced spat growth. The native mussel, G. demissa, had no negative impacts on total settlement, survival and growth of C. virginica; in fact, it increased larval settlement in some trials. These three nonnative species should be classified as invasive because all had negative effects on native C. virginica.  相似文献   

18.
Gerres japonicus Bleeker, 1854, and Gerres subfasciatus Cuvier in Cuvier and Valenciennes, 1830, are redescribed, and Gerres akazakii sp. nov. (Japanese endemic), Gerres ryukyuensis sp. nov. (Okinawa I., Japan), and Gerres shima sp. nov. (Indo-Malayan region, including the Andaman Sea, Southeast Asia, southern China and Taiwan, and Ryukyu Is., Japan) are described. Gerres ovatus Günther, 1859, and Gerres kapas Bleeker, 1854, are recognized as junior synonyms of G. subfasciatus and Gerres oyena (Forsskål, 1775), respectively. All species (except G. oyena) have a small (<170?mm in standard length: SL), moderately deep (depth 36–48% SL), body with dark vertical bars, dorsal fin rays X, 9 or IX, 10, and 31/2 or 41/2 scale rows between the 5th dorsal fin spine base and lateral line, defined as the G. subfasciatus complex. The five species can be variously differentiated from each other by dorsal head squamation, and differing meristic, morphometric, and color characters. They are generally distributed sympatrically in the Indo-West Pacific. Other nominal species of uncertain status or relationship are discussed.  相似文献   

19.
The most important center of speciation in the genus Gagea is thought to be in Central Asia. Here, we focus on species diversity in southeastern Kazakhstan (around Almaty, Ili-Alatau range of the Western Tian-Shan mountains). We studied an elevational transect, reaching from lowland steppes to the alpine zone (500–2750 m a. s. l.), and carried out detailed morphological and molecular investigations for populations of Gagea spp. Nine species were identified in different altitudinal zones; one of these (Gagea almaatensis) is described as new to science. We could detect two altitudinal contact zones between closely related species: G. filiformis and G. granulosa (sect. Minimae), and G. almaatensis and G. kuraminica (sect. Gagea). Morphological and molecular investigations (ITS data and cpDNA networks) indicate ongoing hybridization of co-occurring G. filiformis into G. granulosa and putative bidirectional hybridization events between G. almaatensis and G. kuraminica.  相似文献   

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