scholarly journals Morphology, anatomy and ecology of critically endangered endemic Crocus pestalozzae Boiss. (Iridaceae) in North-West Turkey

1970 ◽  
Vol 38 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Nezahat Kandemir
Keyword(s):  
Early Spring ◽  
Morphological Properties ◽  
Vascular Bundles ◽  
Population Status ◽  
North West ◽  
Plant Parts ◽  
The North ◽  
Anatomical Characters ◽  
Stems And Leaves ◽  
Bulbous Plant

Morphology, anatomy and ecology of endemic species Crocus pestalozzae Boiss. (Iridaceae), have been investigated during flowering period in early spring. The bulbous plant grows in moist heath, meadowland and rocky areas in the North-West of Turkey. Morphological properties of plant parts have been described in detail. Transverse sections of roots, stems and leaves have been illustrated and the anatomical characters of arms, keel, papillae, mesophyll and vascular bundles of leaf have been described. Population status of the plant has also been determined.   Key words: Crocus pestalozzae Boiss.; Endemic; Morphology; Anatomy; Ecology; Turkey   DOI: 10.3329/bjb.v38i2.5136 Bangladesh J. Bot. 38(2): 127-132, 2009 (December)  

Plankton succession and assemblage structure in two neighbouring littoral ecosystems in the north-west Mediterranean Sea

2005 ◽  
Vol 56 (1) ◽  
pp. 69 ◽  
Author(s):  
J.-L. Jamet ◽  
N. Jean ◽  
G. Bogé ◽  
S. Richard ◽  
D. Jamet
Keyword(s):  
Mediterranean Sea ◽  
Physical Environment ◽  
Human Activities ◽  
Early Spring ◽  
North West ◽  
Classical Scheme ◽  
The North ◽  
Seasonal Factors ◽  
Northern Winter ◽  
Plankton Communities

We studied seasonal variations in bacterial abundance and succession in phyto- and zooplankton assemblages (particularly small taxa) in two neighbouring shallow bays (near Toulon, Mediterranean Sea, France): Little Bay (polluted, eutrophic), and Niel Bay (less polluted, oligotrophic). In Little Bay, bacteria developed in northern spring and phytoplankton (Dinophyceae > 20 µm) in late northern winter–early spring. Zooplankton levels peaked at the end of northern spring and in autumn; this community was dominated by Oithona nana. In Niel Bay, bacterial levels peaked during northern spring and autumn. Phytoplankton (Dinophyceae, Bacillariophyceae) abundance was low and only peaked in June. Zooplankton levels peaked in northern mid-summer. Little Bay was influenced more by the land and by human activities than by the sea. Seasonal factors (e.g. water temperature) and sudden influences (e.g. rain and, indirectly, Mistral wind) may have modified the succession of the plankton communities in this bay. Successions did not follow Margalef’s model and the classical scheme for zooplankton. Conversely, Niel Bay functioning and plankton assemblages were most influenced by the physical environment of the sea than by the land or by human activities. Successions were closely related to the classical scheme of the Mediterranean Sea.

The Paradox of Rattus Tunneyi: Endangerment of a Native Pest.

1996 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
RW Braithwaite ◽  
AD Griffiths
Keyword(s):  
Fire Regime ◽  
Wet Season ◽  
North West ◽  
Plant Parts ◽  
The North ◽  
European Colonization ◽  
Riparian System ◽  
The Impact ◽  
North Western ◽  
Population Numbers

An analysis of mark-recapture data for Rattus tunneyi in Kakadu National Park from a 7-year period was performed. Capture rates declined 500-fold during this period. The species exhibits a strong preference for riparian vegetation. The diet is primarily herbivorous, with little insect material. High-nutrient plant parts are generally chosen. Reproduction is most common in the wet season but some breeding extends throughout the year if unseasonal rain occurs during the dry season. Fire regime seems to have little effect on population numbers. The level of groundwater irrigating the riparian system and to a lesser extent current rainfall have a much stronger influence. Museum records show a contraction since European colonization from a near-total continental distribution to one-seventh of its former distribution along the north-west Australian and southern Queensland coast. The contraction from the more arid regions is likely to be due to the impact of introduced mammalian herbivores on the riparian habitats which previously functioned as refuge areas during periods of low water availability. Historically, R. tunneyi is likely to have fluctuated in distribution and abundance throughout the continent. In recent times, this has included irruptions into commercial crops in some areas. The loss of local refuges plus relatively poor powers of dispersal have resulted in the distribution now being fragmented, with the north-western and central east coasts of Australia providing the most significant habitat for the species.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

The North West Passage

2014 ◽  
Author(s):  
Roald Amundsen ◽  
Godfred Hansen
Keyword(s):  
North West ◽  
The North

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

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