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1.
A new acropomatid, Malakichthys barbatus, is described on the basis of 27 specimens (76.3–180.1 mm SL) collected from Suruga Bay to Tosa Bay, along the southern Pacific coast of Japan. The new species is unique in having numerous pairs of spines on the chin (a pair of spines in other congeners). Although the new species resembles M. elegans in having a slender body (the depth less than 35% SL), the former is further distinguishable from the latter in having a slender first proximal radial of the anal fin with no hollow (broad with a cone-shaped hollow in M. elegans), 43–48 lateral line scales (48–51), modally 21 gill rakers on the lower arm (modally 23), and a dark blotch on the opercle (no remarkable blotch). Received: July 2, 2000 / Revised: September 27, 2000 / Accepted: January 30, 2001  相似文献   

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Triplophysa rosa sp. nov.: a new blind loach from China   总被引:2,自引:0,他引:2  
A new blind loach of Triplophysa Rendahl 1933 was collected from a subterranean pool in a cave at Wulong County, Chongqing City, China, in November 2002. The new species, named Triplophysa rosa sp. nov., can be distinguished from its congeners by the following unique characters: eyes vestigial; 9 branched dorsal‐fin rays; 12 branched pectoral‐fin rays; 7 branched pelvic‐fin rays; 6 branched anal‐fin rays; 7 + 7 branched caudal‐fin rays; distal margin of dorsal‐fin concave; tip of pelvic‐fin surpasses vertical level of anus; caudal‐fin deeply forked; whole body scaleless and colourless.  相似文献   

4.
Climatic and biogeographical associations of southern African dung beetles (Scarabaeinae, Coprinae) were analysed from a collection amassed between 1971 and 1986. Endemism to Africa south of 15°S was much greater in southwesterly climates (winter rainfall, bimodal spring/autumn rainfall, arid late summer rainfall) than to the north‐east in the moist, mid‐summer rainfall region. Major biogeographical groups centred to the south‐west comprised predominantly southern African endemics, Western/Eastern Cape coast, Karoo, Karoo/Namib, northern Namibia and the south‐western Kalahari. Biogeographical groups centred on the south‐eastern highlands and the subtropical east coast (mid‐summer rainfall) also comprised predominantly southern African endemics. All other major groups centred to the north‐east in the mid‐summer rainfall region comprised predominantly species with widespread tropical biogeographical affiliations, pan‐southern Africa but centred in the east, pan‐mid‐summer rainfall region, eastern mid‐summer rainfall region, tropical east Zimbabwe/central Moçambique, subtropical/tropical game reserves (non‐ruminant dung specialists). There were cross‐climatic differences in taxonomic composition of the fauna. Within the winter rainfall region, percentage species composition of Scarabaeinae was greater whereas that of the coprine tribe, Onthophagini, was lower than within the other three climatic regions. Percentage species richness of most other tribes of Coprinae differed little between most climates but that of Scarabaeinae declined from west to east (Canthonini, Scarabaeini), east to west (Sisyphini) or to either side of the late summer rainfall region (Gymnopleurini).  相似文献   

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The effects of site characteristics on the distribution of nests and nesting success were examined in the five‐spotted wrasse Symphodus roissali in the north‐western Mediterranean Sea. Nesting males selected nest sites mainly on flat substrata and close to a margin in the rocky littoral strip; however, substratum slope and degree of shelter from wave action were the determinants for a greater success.  相似文献   

7.
Two living specimens of the Atlantic croaker Micropogonias undulatus have been caught during recent years in Belgian waters (Southern Bight of the North Sea): one in August 1998 as a by‐catch of the commercial shrimp fishery in coastal waters, another in October 2001 on a tidal flat in the brackish part of the Scheldt Estuary. These represent the first records of this north‐west Atlantic species in European waters, and their occurrence is likely to be due to transportation in ship ballast water.  相似文献   

8.
A new chimaerid species closely related to Hydrolagus pallidus is described from 13 specimens captured on the Portuguese continental slope (north‐east Atlantic) by commercial longliners at depths of c . 1600 m. The new species is large‐bodied with a rose to light brown body colouration. Hydrolagus lusitanicus n.sp. presents a combination of external morphological characters that allow it to be clearly differentiated from its congeners, in particular, the ratios of pectoral fin length: pectoral fin width and pelvic fin length: pelvic fin width; in having a serrated posterior edge of the dorsal spine; a high number of ridges in the dental plates. Additionally in males, there are differences on the shape and number of hooks in the frontal tenacula, on the number of spines in the prepelvic tenacula and on the length of the pectoral fin margin.  相似文献   

9.
More than 6000 cod Gadus morhua , sampled in coastal and offshore waters stretching from the Barents Sea down to the North Sea, were analysed for frequencies of alleles at the scnDNA pantophysin locus ( Pan I)[formerly called synaptophysin ( Syp I)]. The significant allele frequency difference between the two major stocks of cod in Norway, north‐east Arctic cod (NEAC) and Norwegian coastal cod (NCC), was upheld in all years of the investigation (1993 to 2001), and applied both to larval cod and post‐juveniles of various ages. On a north‐south axis, the appearance of a latitudinal cline of post‐juvenile (≥1 year) allele frequencies was exposed. The intermediate allele frequencies in coastal areas of northern Norway, seem to a large extent to be caused by intermingling of the two stocks, although the existence of populations of coastal cod with alternative Pan I frequencies could not be ruled out. The role of selection is yet unresolved. Depth of the sampling location seemed to have an effect on the allele frequencies and their temporal stability, while there was no indication of seasonal variation in the frequencies. Breeding structure was the most likely cause for upholding the extreme divergence in Pan I frequencies between NEAC and NCC.  相似文献   

10.
Feeding habits and gill raker morphology were examined for the three major planktivorous pelagic fishes, Japanese anchovy Engraulis japonicus , Pacific round herring Etrumeus teres and Japanese jack mackerel Trachurus japonicus , off the northern and western coasts of Kyushu, in the north‐eastern part of the East China Sea in the summer months of 2001. Using fishes in the same size range (80–140 mm, standard length), the stomach contents of the three fish species were compared. The diet of the Japanese anchovy mainly consisted of Oncaeidae copepods, while the diets of the Pacific round herring and Japanese jack mackerel were dominated by calanoid copepods at all stations. Comparisons between prey size in the stomach, zooplankton size in the water and gill raker morphology suggested that the stomach contents of the three species were characterized mainly by the difference in the feeding behaviour between Japanese anchovy (filter‐feeding) and the other two species (particulate‐feeding), rather than by the difference in the morphology of feeding apparatus only. It was concluded that behavioural adaptations in the feeding of these pelagic fishes brought about trophic partitioning to some degree in this pelagic ecosystem in summer. Although the diets of these three species overlapped to some extent, there was still little likelihood of competition between the Japanese anchovy and the other two species. The potential for competition between the Pacific round herring and the Japanese jack mackerel is discussed.  相似文献   

11.
Although goatfishes (Mullidae) include c . 50 specialized bottom foraging species, juvenile and adult spotted goatfish Pseudupeneus maculatus were recorded feeding on plankton on rocky reefs off southern and north‐eastern Brazil, respectively.  相似文献   

12.
 A new liparid, Careproctus parvidiscus, is described on the basis of a single specimen (177 mm in standard length) collected from the southern Okhotsk Sea, off Shiretoko Point, Hokkaido, Japan, at 400–700 m depth. It is distinguished from other congeners by the following combination of the characters: 50 dorsal fin rays, 44 anal fin rays, 10 + 47 = 57 vertebrae, 2 pleural ribs, 14 pyloric caeca being slender and pointed, 2 suprabranchial pores, narrower gill opening, longer lower lobe of pectoral fin, base of uppermost pectoral fin ray almost on a level with center of eye, rudimentary disk, dusky peritoneum, and black stomach. Received: June 13, 2001 / Revised: December 7, 2001 / Accepted: December 22, 2001  相似文献   

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A stichaeid fish, Xenolumpenus longipterus gen. et sp. nov., is described on the basis of 2 specimens (107.1–114.9 mm in standard length) collected from 167 to 300 m in the northern Sea of Japan off southern Hokkaido, Japan. Xenolumpenus is unique among all known genera of the subfamily Lumpeninae in having all pectoral, pelvic, and anal fin rays elongate and unbranched with fin membranes well-incised. Xenolumpenus longipterus can be further distinguished from all species of the subfamily in having the following combination of characters: dorsal fin XLVI–XLVIII; anal fin II, 28–29; pectoral fin 11; large black blotches on pectoral fin; and black ocellus on caudal fin.  相似文献   

15.
One specimen of the largetooth cookiecutter shark Isistius plutodus was caught in the north‐eastern Atlantic at 43°58' N; 28°32' W. This is the first record of this rare species in the north‐eastern Atlantic and the northernmost point of its known distribution.  相似文献   

16.
The biology of elasmobranchs makes them very vulnerable to fishing pressure and there is increasing international concern over their exploitation. In northern Australia the stocks of some species may be shared with those in southern Indonesia. Indonesia has the highest landings of elasmobranchs worldwide (>100,000 t p.a.) and millions of Indonesian artisanal fishers rely heavily on elasmobranchs taken in target fisheries. They are also taken by industrial trawlers and as bycatch in pelagic tuna fisheries. This paper, resulting from a collaborative project between Australia and Indonesia, summarises the elasmobranch fisheries; the characteristics of the fisheries are outlined, the status of the stocks are assessed, and management options described and discussed. The project focussed on representative markets and fish landing sites in southern Indonesia from 2001 to 2005. Data were from market surveys, the records of the Indonesian Directorate General of Capture Fisheries, and from research cruises. Data from the ongoing tuna monitoring programme showed that shark bycatch from the tuna fleets forms about 11% of shark landings in Indonesia. Yield per recruit and related analyses were used to integrate biological information to indicate the productivity of each species to allow for management policy options and constraints. Research cruise data show that catch rates of elasmobranchs in the Java Sea declined by at least one order of magnitude between 1976 and 1997. The results indicate strongly that many of the shark and ray species in Indonesia are overfished and that the most effective management strategy may need to involve capacity control, such as licencing, gear restrictions and catch limits, together with controls on the fin trade.  相似文献   

17.
A 2 year (2000–2001) radio‐tagging study was undertaken to investigate the movements of 51 golden perch Macquaria ambigua in the Murray River at Nyah in north‐western Victoria, Australia. During the winter of both years, golden perch did not undertake movements >5 km and displayed strong home range fidelity. In the first year of the study there was an increase in the distance of golden perch movement during late spring which coincided with increasing water temperature and river discharge. Nineteen golden perch were tracked during this period, of which 10 travelled downstream between 11 and 290 km. Seven of these fish moved to an area below the junction of the Murray and Wakool Rivers. Five golden perch travelled upstream between 13 and 35 km, four of which travelled to an area around the junction of the Murray River and Speewa Creek. The remaining four golden perch undertook localized movements of <5 km. Many of the long distance movements undertaken in spring 2000 were rapid and 53% of these golden perch returned to within 3 km of their release locations, indicating homing behaviour. Given that the rapid movements of golden perch in spring coincided with the known spawning season of this species, these long distance movements may be associated with reproductive strategy.  相似文献   

18.
The marginal increment growth in sagittal otoliths of the myctophid larvae Diaphus slender‐type spp. collected in the north‐eastern East China Sea was examined based on specimens collected at different times of the day. The calcification of the incremental zone began after midnight and took place throughout the day, and the discontinuous zone was formed only around midnight. These results indicate that otolith increments are formed daily.  相似文献   

19.
Reproductive biology of gag in the southern Gulf of Mexico   总被引:1,自引:0,他引:1  
Aspects of the reproductive biology of gag Mycteroperca microlepis in the southern Gulf of Mexico were studied by following seasonal variations in the gonado‐somatic index and through histological examination of gonads. Gag were collected from inshore and offshore waters of the Campeche Bank, Yucatan, Mexico, between April 1996 and December 2001. This species is a protogynous hermaphrodite, and appeared to be depth‐size distributed. The smallest gag (9–49 cm L F) collected were all juvenile females, and were caught in inshore waters (1–10 m depth), while the largest (49–116 cm L F), mainly adult females, males and transitionals, were captured in offshore waters (33–167 m depth). Overall the offshore male to female ratio was female‐biased (1 : 3·3) and differed significantly from unity. The species spawns at depths of c . 50–53 m, from early winter to mid‐spring, with peak spawning activity occurring between January and March. Fifty per cent of females reached first maturity at 72·1 cm L F. At 103 cm L F, 50% of sampled females had changed into males. Gag can be considered a monandric species, and sexual transition for this grouper seemed to occur in fish distributed within a narrow size range (85–111 cm L F). The results are compared with those of other authors for gag stocks from the south‐east Atlantic coast of the U.S.A. and the north‐east Gulf of Mexico.  相似文献   

20.
An undescribed goby has been collected from several localities in the western troplcal Pacific, from Japan to Australia. This species is described as a new species,Fusigobius signiplnnis. It differs from other species ofFusigobius in pectoral ray counts, colouration, largely separate pelvic fins, and shape of the first dorsal fin. The species is found in groups on sand, frequently flicking its first dorsal fin. Males are larger than females in mean size. Sex ratios are uneven, and females are twice as numerous as males.  相似文献   

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