摘要:

Bathylychnops exilisis an unusual north‐eastern Pacific mesopelagic fish of which adults have previously been undescribed and the biology is poorly known. Its sensory and digestive systems are highly modified. Sensory modifications include the equivalent of four functional eyes, well developed nasal rosettes, and lateral line canals up to 4 mm in diameter. Digestive adaptations include a peculiar mouth, large tongue, crumenal organ, and a large caecal stomach.Bathylychnops exilisapparently lacks an anal light organ. Ontogenetic changes occur in the morphology of the head, eyes, body, and coloration.Bathylychnops exiliseats crustaceans and may be medusae and microscopic organisms. Reproduction probably occurs in late summer. Adults occur most commonly at about 500 m depth, possibly in groups, and may be diurnal vertical migrator

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04022.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Fecundity, length at first spawning, spawning seasonality and ovarian development ofSpratelloides graciliswere determined by examining preserved ovaries from fish captured over a 5‐year period. Fecundity (F) was estimated from the number of eggs in the most advanced ovarian mode and was related to fish length (L) by the function: logeF=3.764 logeL‐7.308, and to weight (W) by: logeW= 1.210 logeW+7.337. Spawning was observed in most months of the year without any recognizable pattern between the years. Ova diameter frequencies were bimodal but the smaller mode remained stationary regardless of the position of the larger mode. This was interpreted as evidence that individual fish may spawn only once. From data on egg length versus fish length and gonad index versus fish length it was estimated that fish were first capable of spawning at 45 mm (fork leng

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04023.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Acute temperature preferenda and critical thermal maxima were determined for 23°C‐acclimated stocks of grass carp, bighead carp and their F, triploid hybrid. Preferred temperature and critical thermal maximum of the hybrid were significantly higher than those of the grass carp (female parent), which is consistent with prior field observations. The hybrid's values for both parameters also were significantly higher than those of the bighead carp. These results comprise experimental evidence for substantial heterosis in the thermal physiology of fish

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04024.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A biological study of the adult population of the Suez Canal migrant, the squirrelfish,Sargocentron rubrum, in the Mediterranean coast of Israel, was carried out between October 1979 and October 1980.Sargocentron rubrumin the Mediterranean has a short spawning season lasting from July to August. The estimated fecundity varied from 108 000 to 646 000 oocytes per mature female. The largest ripe oocytes reach a diameter of 200 μm. The ratio of males to females was found to be 1:2. Hyaline rings on otoliths were used for aging. Growth rate was obtained by back calculation and by using von Bertalanffy's equation. The results obtained from both methods were close, 94mm S.L. after 16 months, 125–127 mm after 28 months, 143 144mm after 40 months and 155 mm after 52 months. Age groups older than 4 years were not found in the present study. The descriptions of early stages of development were based on samples collected by dip and neuston nets along the Mediterranean coast of Isra

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04025.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Haematological characteristics ofClarias isheriensis, a freshwater teleost, were established as a ‘working document’ upon which to base more extensive studies. Correlations were found with certain blood factors as functions of the physical parameters of length and weight. Other correlations which were not related to the physical size were also found. Factors which affect the haematological picture offish are discus

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04026.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Anterior kidney and splenic cells were taken from rainbow trout and splenic cells from BALB/c mice immunized with a T‐dependent (sheep red blood cells) or T‐independent (DNP‐Ficoll) antigen. The cells were incubated at different temperatures in Jerne plaque assays (direct or passive haemolytic plaque assays). The optimum numbers ofin vitroplaque‐forming cells (PFC) after incubation with homologous complement were directly correlated with normal body temperatures of the respective species. The optimum incubation temperature was 37°C for mouse cells and 10°C for fish cells. Incubation of mouse cells at lower temperatures of 30, 20, 10, 4 or 0°C appeared to yield a direct line reduction in numbers of PFC. Trout cells developed significantly fewer PFC at 4 and 20°C and none at 30°C or above; however, significant numbers still appeared at 0°C. More PFC per million white blood cells were obtained from the anterior kidney; however, related to temperatures, no differences in development of numbers of PFC could be seen between the spleen and anterior kidney cells of trout. When the incubation time was lengthened for both trout and mouse cells held at low temperatures, the numbers of PFC approached those of the cells incubated at the optimum temperat

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04027.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A combination of fixatives and stains were applied to the adenohypophysis of the kelp greenling,Hexagrammus decagrammus, to determine which were the most suitable for observation under a light microscope. Lillie's calcium acetate formalin (LCAF) followed by haematoxylin and eosin, lead haematoxylin/periodic acid‐Schiff and alcian blue/periodic acid‐Schiff/orange G provides the best general staining characteristics. Lactotropes, corticotropes, thyrotropes, somatotropes, gonadotropes and two types of melanotropes were effectively identif

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04028.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The larval ontogeny ofHypseleotris galiiis described and illustrated. ‘Premature’ yolk sac larvae hatch with unpigmented eyes and no mouth. ‘Late’ yolk sac larvae hatch with pigmented eyes and a functional mouth. Hatching glands are distributed on the head and ventral surface of the body. The yolk is absorbed and the larvae begin feeding 6 days after hatching. Larval development is completed 74 days after hatching.Hypseleotris galiilarvae have six pairs of naked neuromasts: two pairs on the head and four pairs on the body. The significance of these results to developmental strategies inHypseleotrisspecies is di

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04029.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The origin and species differentiation of the Philippine medaka,Oryzias luzonensis, was studied by means of karyotype analyses and interspecific hybridyzations. The karyotype revealed2n =48 consisting of 24 pairs of biarmed chromosomes (NF = 96). Characteristic C‐bands were found in three sub‐metacentric pairs. Nucleolar organizer regions (NORs) were detected on the short arms of the satellited sub‐metacentric pair. Estimated DNA‐value was 1.9 pg per nucleus. Interspecific crosses revealed thatO. luzonensiswas allied most closely toO. latipes(biarmed chromosome type), less closely toO. celebensis(fused chromosome type), and least closely toO. melastigmaandO.javanicus(monoarmed chromosome type), which are distributed in east Asia, the Sulawesi, and south‐west Asia and west side of south‐east Asia, respectively. The external appearance ofO. luzonensiswas also more similar to that ofO. latipes. From these results, we concluded thatO. luzonensisis a member of the biarmed chromosome group and the nearest relative toO. latipes. Thus, the Philippine medaka seems to be of east Asiatic origin, having migrated to northern Luzon from the China continent

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04030.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A selection of neoplasias in feral fish is described. It includes olfactory glioma in coalfish,Pollachius virensL.; nephroblastoma with metastases and polycystic kidneys in crucian carp,Carassius carassius;lymphosarcoma in roach,Rutilus rutilus, and bream,Abramis bratna;and stomato‐papilloma in eel,Anguilla anguilla. The olfactory glioma is one of a few recordings of a central nervous system‐derived tumour in teleosts. Although nephroblastoma is relatively common in fish, rarely have metastases been observed. The lymphosarcomas in roach and bream have not been recorded before in the British Isles, but now stomato‐papillomas in eel appear to be established at a low

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1985.tb04031.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY