40 resultados para new forms of resistance
Resumo:
A feeding strategy model is proposed using stomach content and resource availability data as a modification to Costello (1990) and Amundsen et al. (1996). Incorporation of feeding electivity index (E) instead of the prey-specific abundance signifies the importance of resource availability in prey selection as well as the predator's ability to specialize, generalize or avoid particular prey items at the individual and population level.
Resumo:
During the stay of the vessel "Ob" (Soviet Antarctic Expedition) at Colombo, May, 1957, the author received from Dr. C. H. Fernando some specimens of different species of fishes from Ceylon, preserved in formalin, as a present for the Zoological Institute (Academy of Sciences of the U.S.S.R.) New species of Monogenoidea have been found when examining the gills of the fishes received and the present paper deals with their description. The material was preserved in strong formalin which highly condensed the tissues of the parasites. Therefore the details of the anatomical structure in most of the specimens could not be recognized even by means of phase-contrasting equipment. So the description is confined almost exclusively to the chitinoid armature of the haptor and copulatory organ. The terms and the measurements used in this paper are the same as those used previously (Gussev, 1955).
Resumo:
Excirolana orienta/is (Dana, 1853) belonging to the Cirolanidae, hitherto unknown from Pakistan, is collected from the rocky intertidal region of Manora Island, Karachi coast The specimens are fully described and illustrated. A list of the known species of the genus Excirolana is also provided since the genus is also first time reported from here.
Resumo:
Result of experimental lobster fishing with three new designs, namely rectangular, Australian pot and ink-well traps at Muttam, Kadiapatnam, Colachal, Enayam and Vizhinjam, south-west coast of India during 1979-80 are reported. Preliminary studies show that Australian pot and rectangular traps as more efficient to the ink-well type.
Resumo:
Descriptions with suitable illustrations of two species of palaemonid prawns - Macrobrachium aemulum and Palaemon (Palaemon) concinnus are furnished. M. aemulum has been enjoying an isolated distribution in New Caledonia. It is reported for the first time from India and is therefore a clear case of discontinuous distribution. Studies revealed that M. aemulum is distinct from M. nobilii and the reasons for separating the two species are discussed. New distributional records for P. (P.) concinnus in the south-west coast of India are also given.
Resumo:
Total concentrations and chemical forms of heavy metals in sediment samples from the Gulf of Suez and the northern part of the Red Sea, collected during January 2003, were determined by atomic absorption spectrometry. Maximum concentrations of 49.56, 65.42, 33.52 and 3.52 µg/g were recorded for total Cu, Zn, Pb and Cd respectively at Adabiya location. These may reflect the high contribution of land-based activities in the northern part of the Gulf. Also, high percentages of heavy metals were found in the residual fraction (Cu=78.61, Zn=77.10 and Pb=66.80%) while a high percentage of Cd was found in the carbonate fraction (45.82%). However, few or negligible percentages were recorded in the exchangeable fractions (Cu=0.51, Zn=1.57 and Pb=1.74%). Concentration of Cd in the exchangeable fraction was too low to be detected.
Resumo:
Berea clava, new species, is described based on the specimens recovered from the gill filaments of a flounder, Pseudorhombus arsius (H.-B.), collected in Kuwait Bay of Arabian (Persian) Gulf. This is the second species of Berea.
Resumo:
The tetraclitid fauna at Elat, Israel, on the Gulf of Aqaba, Red Sea, consists of three morphologically distinct species. Tetraclita rufotincta Pilsbry, 1916 was reported previously from this region and may have been confounded with T. achituvi n.sp. and T. barnesorum n.sp. Although these species occur sympatrically, according to previous studies, and recent observations, they apparently occupy different levels in the narrow intertidal zone (=50 cm) of this area. Cirral morphology suggests that each differs in the manner by which they capture and manipulate prey. Little is known about the occurrence of these new species elsewhere in the Red Sea and adjoining Arabian Sea.
Resumo:
This paper describes six species of polychaete worms, which are new records from Pakistan. The species are: Arabella iricolor (Montagu), Capitella capitata (Fabricius), Mesochaetopterus sagittarius (Claparede), Phyllochaetopterus herdmani Willey, Lysidice natalensis Kinberg and Marphysa depressa (Schmarda).
Resumo:
A new species of myxosporida, Henneguya clariae, is described from the gills of Claria’s Iazera caught from various waters in Nigeria. Pathogenic effects in the destruction of the components of the branchial system are about 25% of Clarias lazera. A review of the genera Henneguya myxobilatus, and Neohenneguya is made and these were synonymised, with some reservations in the case of to Henneguya. A checklist of the genus Henneguya is given.