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1.
The fungus Schizoxylon albescens occurs both as lichen and as saprobe. Lichenized colonies grow on the bark of Populus tremula; saprotrophic morphs grow on dead Populus branches. We wanted to (1) test whether lichenized and saprotrophic S. albescens are genetically distinct, (2) investigate photobiont association and diversity, (3) investigate the interactions between fungi and algae that occur during co-cultivation and (4) test whether Schizoxylon shows algal selectivity during lichenization. Fungal and algal genetic diversity were investigated for three markers. Algae from lichenized thalli were isolated in axenic cultures, and isolate sequence diversity was compared with algae amplified directly from thallus fragments. Co-culture experiments of fungi and algae were performed to study the morphological interaction patterns. Two distinct phylogenetic units are revealed in S. albescens, which are interpreted as phenotypically cryptic species. The algae are related to Coccomyxa and Pseudococcomyxa, and form two distinct sister clades separating samples isolated in cultures from those amplified directly from thallus fragments, indicating that more easily cultured strains of algae are not necessarily major components of the lichens. Schizoxylon albescens interacts with isolated algal strains, similar to fungal-Coccomyxa symbioses in nature. As the system is maintained without difficulty in culture, it can potentially be an easily controlled lichen symbiosis study system under laboratory conditions.  相似文献   

2.
Three species of the bunocotyline genus Saturnius Manter, 1969 are described from the stomach lining of mugilid fishes of the Mediterranean and Black Seas. Two of the species are new: S. minutus n. sp. occurs in Mugil cephalus off the Mediterranean coast of Spain; and S. dimitrovi n. sp., a parasite of M. cephalus off the Bulgarian Black Sea coast and the Spanish Mediterranean coast, was originally described as S. papernai by Dimitrov et al. (1998). In addition, S. papernai Overstreet, 1977 is redescribed from M. cephalus off the Spanish Mediterranean coast and from Liza aurata and L. saliens off the Bulgarian Black Sea coast. The three species are distinguished morphometrically using univariate and multivariate analyses. These results were verified using Linear Discriminant Analysis which correctly allocated all specimens to their species designations based on morphology (i.e. 100% successful classification rate) and assigned almost all specimens to the correct population (locality). The following variables were selected for optimal separation between samples: the length of the forebody, ventral sucker and posterior testis, the length and width of the posteriormost pseudosegment, and the width of the muscular flange at ventral sucker level.  相似文献   

3.
Aphanurus stossichii (Monticelli, 1891) is redescribed from Boops boops (L.) from various localities in the NE Atlantic region (off Spain), the Mediterranean (off Spain and Turkey) and the Black Sea (off Bulgaria). The material from the Atlantic coast of Spain showed differences in egg-size and shape and a characteristic ornamentation of the anterior third of the hermaphroditic duct. A comparison with samples from B. boops collected off Antalya (Turkey) and off the Bulgarian Black Sea coast revealed a considerable size variation and confirmed the presence of tubercles in the terminal part of the hermaphroditic duct. A. virgula Looss, 1907, previously considered a synonym of A. stossichii, is redescribed on the basis of voucher material from Engraulis encrasicolus ponticus Alexandrov collected off the Bulgarian Black Sea coast and previously identified as A. stossichii. A. virgula can be distinguished from A. stossichii by its smaller size and substantially lower range limits for all metrical features, the more posterior position of the base of sinus-sac, and the eggs being less numerous and larger in relation to the size of the body and gonads.  相似文献   

4.
 Significant coral reef ecosystems occur along the northwest (NW) coast of Australia in an oceanographic setting somewhat similar to that of the Great Barrier Reef off the northeast (NE) Australian coast. Seasonal and inter-annual variations of several surface climate variables are described for the NW coastal region of Australia from 10°–30°S over the period 1960 to 1992. Average climatic conditions in this region are compared with those for similar latitudes on the Great Barrier Reef. On average, sea surface temperatures (SSTs) along the NW Australian coast are warmer than at similar latitudes along the NE coast north of ∼20°S and cooler than the NE coast at higher latitudes. The annual range of SSTs along the NW coast is lower than found along the NE coast. There is also lower average cloud amount (and greater incoming solar radiation) along the NW coast compared with the NE coast. Corals reefs off the NW Australian coast are less likely to be influenced by freshwater and associated terrestrial impacts than nearshore reefs of the GBR. Although the latitudinal distribution of tropical cyclone activity is similar along the NW and NE Australian coasts, the total number of tropical cyclones and tropical cyclone days is substantially higher on the NW coast compared with the NE coast. Accepted: 22 June 1998  相似文献   

5.
The taxonomic classification of large head hairtail (Trichiurus lepturus) is controversial because of similar body appearance and silvery coloration. Ten samples of T. lepturus caught off the west coast of Africa and 43 samples of T. lepturus caught off the western Atlantic coast and Indo-Pacific waters were used for sequence comparison of mitochondrial DNA encoded partial 16S ribosomal RNA(16S rRNA) gene. Ten samples of T. japonicus (obtained from various parts of southern Japan) were also included in the comparative analysis. For the 509 bp sequence determined, 58 sites were variable, of which 53 were parsimony informative. Phylogenetic analyses using maximum parsimony, maximum likelihood and Bayesian algorithm with Eupleurogrammus muticus as outgroup, showed that the haplotypes of T. lepturus obtained from the West coast of Africa, Indo-Pacific and Western Atlantic coast constituted clearly distinct and well supported lineages without any sharing and overlapping between them. Previous morphological analyses and this genetic study strongly indicate that the morphotypes of T. lepturus obtained from the West African coast are genetically distinct and probably represents a separate species.  相似文献   

6.
儒艮在中国近海的分布   总被引:5,自引:3,他引:2  
儒艮Dugong dugon(Muller,1776)隶属海牛目Sirenia,儒艮科Dugongidae,俗称海牛,又称人鱼,海南岛渔民称海马。以往中国沿海产儒艮的研究甚少,只Hirasaka(1932)和寿振黄(1958)有过头骨及骨骼的描述报道,对其生态及分布方面的调查研究还没有深入的开展。1962年、1981年和1984年我们对儒艮在中国沿岸的分布进行了调查访问,并对近年所得儒艮的外形作了一些测量。现将所得资料整理报道。  相似文献   

7.
Pop-up satellite archival tags were attached to six Atlantic bluefin tuna (Thunnus thynnus) off the west coast of Ireland in autumn 2003 and 2004. The satellite tags measured pressure, ambient temperature and light for the term of deployment. Radio pop-up satellite endpoint positions, light and sea surface temperature estimations of geolocation indicate that two fish tagged minutes apart off the coast of County Donegal, migrated to the eastern and western Atlantic Ocean over the following 8 months. The two fish were 5218 km apart at the termination of the experiment. After tagging in September and popping up the following March and April, one fish had traveled to the western Atlantic while the other was located in the waters off the southwest coast of Portugal. A third fish tagged off the coast of County Donegal in October 2004 moved into the Mediterranean Sea and was caught by a fishing vessel southeast of Malta on 11 June 2005. The results link bluefin tuna feeding on European foraging grounds with known eastern breeding regions and western Atlantic waters.  相似文献   

8.
9.
Photographic identification of the Korean-Okhotsk gray whale Eschrichtius robustus population has been conducted since 2002 by researchers of the Institute of Marine Biology at the Far East Branch of the Russian Academy of Sciences (IMB FEB RAS), with financial support provided by Exon Neftegas, Ltd. and Sakhalin Energy Investment Co., in order to study the migration features and biology of this species. In 2008, photo-ID studies were carried out in two areas, off the northeastern coast of Sakhalin Island and off the southeastern coast of Kamchatka. As a result of the studies, 122 whales known from the Sakhalin gray whale catalogue were photographed. Of them, 97 individuals were registered off Sakhalin, 24, off Kamchatka, and one whale was observed at both sites. In addition, 25 more gray whales that had not been sighted off Sakhalin Island before were found off the coast of Kamchatka. Based on these photographic materials, the whales physical and skin conditions were also analyzed. Cases of sightings of gray whales in areas that are remote from their traditional summer and fall feeding grounds in the Far Eastern seas of Russia are discussed.  相似文献   

10.
Thaumatocotyle roumillati n. sp. is described from specimens collected in the nasal fossae of the Atlantic stingray, Dasyatis sabina (Lesueur) from the southeastern coast of the United States, off South Carolina. Thaumatocotyle roumillati is distinguished from congeners by the size and shape of its penis as well as the presence of a spinelike accessory piece associated with the penis.  相似文献   

11.
Results of analysis of similarity of size series of mature females of the lumpfish Cyclopterus lumpus collected on the spawning grounds in the Barents and Norwegian seas (Russian and Norwegian coasts), as well as in the areas of its feeding, are provided. The trajectories of feeding migrations of lumpfish in the southern part of the Barents Sea have been revealed. A clinal decrease in the average length of females in the range from west to east is shown. The area of feeding aggregations of lumpfish spawning off the Russian coast is distinguished. The boundaries of the census water area used to assess the commercial stock of lumpfish and to determine the values of its possible catch off the coast of Murmansk are specified.  相似文献   

12.
Orlov  A. M.  Sytov  A. M.  Marí  N.  Figueroa  D. E.  Barbini  S. A.  Costa  P. A. S.  Marin  Y. H.  Mincarone  M. M. 《Journal of Ichthyology》2019,59(2):174-185
Journal of Ichthyology - Long-term data on spatial and bathymetric distributions, preferred bottom temperatures, length and weight of blue hake Antimora rostrata caught off the Atlantic coast of...  相似文献   

13.
Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.  相似文献   

14.
A total of 690 herring Clupea harengus L. and 88 sprat Sprattus sprattus L. caught off the west coast of Sweden, in the North Sea and off the west and south coasts of the United Kingdom, were examined for gill parasites. The monogenean Pseudanthocotyloides heterocotyle (van Beneden, 1871) Euzet & Prost, 1969 was found in 38 (5.5%) herring and one (1.1%) sprat. The parasite was significantly (P>0.05) more common off the west coast of Sweden than elsewhere and most specimens (62.5%) were found on the pseudobranchs. Only the smaller herring were infected. P. heterocotyle is redescribed and its taxonomy discussed, together with the possibility of host and parasite misidentification in previous reports.  相似文献   

15.
Galil  Bella S.  Mienis  Henk K.  Hoffman  Razy  Goren  Menachem 《Hydrobiologia》2021,848(9):2011-2029
Hydrobiologia - Of the 452 multicellular non-indigenous species (NIS) recorded off the Israeli Mediterranean coast, nearly 90% are considered to have been introduced through the Suez Canal...  相似文献   

16.
Chimaericola ogilbyi n. sp. and C. colliei n. sp. are proposed for chimaericolids found on the gills of the ghost shark, Hydrolagus ogilbyi taken off the coast of southeastern Australia, and the ratfish, H. colliei, taken off the coast of Vancouver Island, respectively. Supplementary observations on C. leptogaster, the type-species of the genus Chimaericola, are included. The two new species are differentiated on the size and shape of the median sucker sclerite, hamuli, spines of the male copulatory apparatus and eggs. Amended diagnoses for the family Chimaericolidae and genus Chimaericola are provided.  相似文献   

17.
18.
Wajira albescens Thulin (Leguminosae–Papilionoideae–Phaseoleae–Phaseolinae) is described as a new monotypic genus confined to the arid bushlands of E Kenya.  相似文献   

19.
Most coral species off Australia??s west coast spawn in the austral autumn (March?CApril), with a few species also spawning in the southern spring or early summer (November?CDecember). This is the reverse timing to spawning recorded off Australia??s east coast. Porites lutea, a gonochoric broadcast spawner that is common on Australia??s west coast, is shown here to spawn in the months of November or December, as it does on Australia??s east coast. Spawning occurred between 2 and 5 nights after full moon, with the majority of spawning activity on night 3. Gametes developed over three to four months with rapid development in the last two weeks before spawning. Zooxanthellae were typically observed in mature oocytes, only a week before spawning so their presence may provide a useful indicator of imminent spawning.  相似文献   

20.
Systematic Parasitology - Eutetrarhynchus pacificus n. sp. is described from the spiral valve of Raja inornata Jordan & Gilbert off the coast of California, USA. The new species is...  相似文献   

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