918 resultados para introduced marine species
Resumo:
Morphology and taxonomy of four species of Ulva i.e. U. anandii Amjad et Shameel sp. nov., U. bifrons Ardre, U. saifullahii Amjad et Shameel sp. nov. and U. taeniata (Setchell) et Gardner were described for the first time from Pakistan. Their anatomy has been investigated in detail and compared with the allied species. A taxonomic comment has been written on U. grandis Saifullah et Nizamuddin.
Resumo:
The study deals with a series of experiments to investigate feeding and excretion in three species of bivalves: Perna viridis (Linné), Marcia cor (Sowerby) and Cassostrea gryphoides (Gould) from Manora Channel, Karachi. Bivalves were fed with suspensions of Ankistrodesmes labelled with P³². These animals showed a considerable variation in the average filtration rates depending upon species and the body lenght. Exceptionally high content of the P³² introduced with Akistrodesmes, got excreted as pseudofaeces and faeces within first three days following its absorption as a meal. The assimilated P³² is partly released as faecal material and its major proportion is directly transferred to the solution. As expexted the gonad and kidney are the main organs found responsible for excretion as comared to other body parts. Although, the assimilated P³² is mostly concentrated in the digestive glands, the results also show a significant presence of P³² in the gonads. Accumulation of P³² was the least in the foot.
Resumo:
Aquous extracts of 24 species of green seaweeds, 13 of Caulerpa Lamour and 11 of Ulva Linn, were collected from the coastal areas near Karachi, Pakistan and tested for haemagglutination against human erythrocytes of blood groups A,B,AB and O and compared. All the species of Caulerpa and seven of Ulva exhibited a positive activity, the former genus (a member of Bryopsidophyceae) appeared to possess more phycohaemagglutinins than the latter (a member of Ulvophyceae). The haemagglutinic activity proved to be quite helpful in the distinction of various species of both the genera.
Resumo:
This paper deals with the male reproductive organs of nine species of penaeid prawns; Penaeus penicillatus Alcock, P. merguiensis De Man, P. semisulcatus De Haan, Metapenaeus affinis (H.Milne Edwards), M. monoceros (Fabricius), M. stebbingi Nobili, Parapenaeopsis hardwickii (Miers), P. sculptilis (Heller) and P. stylifera (H. Milne Edwards). The male reproductive organs exhibited structural variations, which were more pronounced at generic level. These variations are mainly due to the type of spermatophore they possess. One species of each genus, that is, P. merguiensis, M. affinis and P. sculptilis were also studied histologically to examine the internal structure of the male reproductive organs. Spermatophores of the six species belonging to the genera Penaeus and Parapenaeopsis are also described and illustrated.
Resumo:
A female of Penaeus merguiensis de Man collected from Karachi fish harbour (8 May, 1993) was with a large specimen of bopyrid in its right gill chamber. Since this was the second record (see Tirmizi and Bashir, 1973) of a bopyrid from a species other than Parapenauopsis stylifera H. Milne-Edwards the specimen was examined out of curiosity.
Resumo:
In India the chief marine timber boring organisms are 2 species of Martesia, 28 species of shipworms, 4 species and a variety of Sphaeroma and 9 species of Limnoria besides bacteria and fungi. The occurrence, abundance and activity of the various species of borers show remarkable variations and fluctuations in the different harbours of India, each harbour or area having its own dominant set of species and an assemblage of less important forms. These species have their own characteristic preferences, life history and seasons of attachment and a scheme evolved for one locality may prove ineffective for another. Through a delicate and complex ecological adjustment the borers occurring in a locality have reached an interrelationship reducing interspecific and intraspecific competition. The seasons of settlement of the dominant borers in the different harbours of India are indicated. The need for a detailed biological enquiry is stressed.
Resumo:
The paper contains a brief review of the studies on the life histories of Indian species of prawns chiefly belonging to the family Penaeidae. References to similar work carried out outside India are furnished where significant variations have been observed. The three main larval stages viz., Nauplius, Protozoea and Zoea (Mysis) and their important characteristics, including modes of locomotion, are described. The post-larval development of one species that has been studied in detail (Metapenaeus dobsoni) is indicated in outline. Some aspects of the bionomics of these prawns, especially breeding and migration, are also briefly dealt with in view of their relevance in their life cycle. An outline of the life histories of some Palaemonid prawns of both fresh water and marine habitats is added at the end and the need for well- planned investigations in regard to species of such economic value as Palaemon carcinus (Macrobrachium rosenbergii) is indicated.
Resumo:
Marine fish doma (Sciaenoids) (Small spp.) from Bombay coast was studied for total bacterial counts on the surface and gut. Large number of Micrococcus species (77.4%) was found whereas few species from Achromobacter, Bacillus, Bacterium, Flavobacter, Pseudomonas and Sarcina were noted.
Resumo:
Since his last publication "Contribution to the Study of the Marine Algae of Ceylon"(1961), the author has made several collections which contain interesting material which he has not hitherto described. This and any other material which he come across in future surveys will be described in a series of papers of which this is the first. The present paper includes the description of fourteen species of which three are new to science. These are deposited in the Herbarium of the Royal Botanical Gardens, Peradeniya, Ceylon.
Resumo:
A new species Amphisolenia nizamuddinii Mansoor and Saifullah sp. nov. and a new variety Amphisolenia schroederi var. pakistanensis Mansoor and Saifullah var. nov. are hereby described from Pakistan's shelf and deep sea vicinity during the transition period between the northeast and southwest monsoon seasons.
Resumo:
Sphaeromopsis minutus, sp. nov., the sixth species of Splitteromopsis Holdich and Jones is described and figured in detail. The genus Sphaeromopsis and species S. serriguberna Holdich and Harrison, 1981 is recorded for the first time from northern Arabian Sea, Karachi (Pakistan).
Resumo:
The present paper includes a new species and a new record of majid crabs. The new species is referable to the genus Cyphocarcinus, subfamily Mithracinae of which only the genus Micippa was known from the region. Macropodia formosa Rathbun is being recorded for the first time from Karachi and belongs to the subfamily Inachinae. Both the species are described and illustrated. The new species is compared with its allied species.
Resumo:
Sinum haliotoideum (Linnaeus, 1758) was collected on only two occasions. However, it was given attention when the recently collected specimen netted on 24 August, 1993 was brought live to the laboratory where its movement towards the source of light was noticed, leading to a careful examination and illustration. The specimen survived for 4 days. Illustrations and shell from the earlier collected specimen (August, 1991) were sent to Dr. Alan R. Kabat, division of Mollusck, National Museum of Natural History, Smithsonian Institution, USA, who confirmed that the specimen was Sinum haliotoideum (Linnaeus, 1758). He further informed that this is a moderately common Indo-Pacific species. The material has been deposited in the collections of the Marine Reference Collection and Resource Centre. (MRC) The species being new to the region is briefly described.
Resumo:
Five species of crabs and three species of fishes were the main marine organisms found damaging embankments owing to their burrowing nature. Among crabs, Scylla serrata was in the highest percentage, while among fishes, Boleopthalamus dussumieri was recorded in maximum percentage calcium carbide 10-15 per burrow was effective in eradicating the crabs.
Resumo:
The herbarium material belonging to the genus Laurencia kept at the Royal Botanical Gardens, Peradeniya together with my collections of material belonging to this genus from various parts of Ceylon have been examined. Most of the material belonging to the genus Laurencia had been incorrectly identified and their true identity has been determined. A key to the Ceylon species of Laurencia is given.