Growth and reproductive characteristics of the Bluefish Pomatomus saltatrix (Linnaeus, 1766) in the Marmara Sea

To obtain further perspective on reproduction and particularly gamete function among so-called primitive mammals presently grouped in the Order Insectivora, we have examined the African hedgehog, Atelerix albiventris, in light of unusual features reported in shrews and moles. Atelerix proves to share many but not all of the characteristics seen in these other insectivores. The penis of Atelerix has a 'snail-like' form, but lacks the surface spines common in insectivores and a number of other mammals. Hedgehog spermatozoa display an eccentric insertion of the tail on the sperm head, and they manifest the barbs on the perforatorium that, in shrews, probably effect the initial binding of the sperm head to the zona pellucida. As a possible correlate, the structural matrix of the hedgehog acrosome comprises only two main components, as judged by immunoblotting, rather than the complex of peptides seen in the matrix of some higher mammals. The Fallopian tube of Atelerix is relatively simple; it displays only minor differences in width and in the arborized epithelium between the isthmus and ampulla, and shows no evidence of the unusual sperm crypts that characterize the isthmus or ampulla, depending on the species, in shrews and moles. In common with other insectivores, Atelerix appears to be an induced ovulator, as judged by the ovulation of some 6-8 eggs by about 23 h after injection of hCG. The dense cumulus oophorus appeared to have little matrix, in keeping with the modest dimensions of the tubal ampulla and, while it was not quite as discrete as that of soricids, it did show the same insensitivity to 0.5% (w/v) ovine or bovine hyaluronidase.

Download Full-text

Reproductive Characteristics of Winter Wheat Cultivars Subjected to Postanthesis Shading

Crop Science ◽

10.2135/cropsci1990.0011183x003000040002x ◽

1990 ◽

Vol 30 (4) ◽

pp. 771-774 ◽

Cited By ~ 10

Author(s):

L. J. Grabau ◽

D. A. Van Sanford ◽

Q. W. Meng

Keyword(s):

Winter Wheat ◽

Wheat Cultivars ◽

Reproductive Characteristics ◽

Winter Wheat Cultivars

Download Full-text

The Black Sea factor influencing the wastewater disposal strategy for Istanbul

Water Science & Technology ◽

10.2166/wst.1995.0202 ◽

1995 ◽

Vol 32 (7) ◽

pp. 63-70

Author(s):

I. Ethem Gönenç ◽

Oguz Müftüoglu ◽

Bilsen Beler Baykal ◽

Ertugrul Dogan ◽

Hüseyin Yüce ◽

...

Keyword(s):

Black Sea ◽

Satellite Images ◽

The Black Sea ◽

Marmara Sea ◽

Research Institutions ◽

Trophic Conditions ◽

Wastewater Disposal ◽

The World ◽

Collaborative Efforts

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.

Download Full-text

Environmental model studies for the Istanbul master plan. Part I: hydrodynamical design basis and marine disposal of wastewater

Water Science & Technology ◽

10.2166/wst.1995.0090 ◽

1995 ◽

Vol 32 (2) ◽

pp. 141-148 ◽

Cited By ~ 1

Author(s):

I. S. Hansen ◽

H. J. Vested ◽

M. A. Latif

Keyword(s):

Black Sea ◽

Layer Structure ◽

The Black Sea ◽

Marmara Sea ◽

Junction Area ◽

3 Dimensional ◽

Model Studies ◽

Model Set ◽

Characteristic Features ◽

Set Up

A modelling study of the hydrodynamics and spreading of wastewater from existing and future outfalls in the Bosphorus region has been conducted applying a 3-Dimensional model. The modelling is based on SYSTEM 3, which is a general modelling system for baroclinic flow simulating unsteady currents, waterlevels, salinity and temperature within the model area. The model set-up covers the Black Sea-Bosphorus-Marmara Sea junction area. The set-up is calibrated by data from a dedicated field program and previous field experience. The model is designed to describe the characteristic features of the flow in the junction area such as the effects of variations in waterlevel differences between the Sea of Marmara and the Black Sea on the important two-layer structure in the strait and the flow fields generated by the upper layer jet in the Bosphorus-Marmara junction. This model has been applied for evaluation of disposal of wastewater and for the subsequent water quality studies. The general use of a baroclinic 3-D hydrodynamic model to simulate disposal of wastewater is discussed. Examples of the application of the model of the junction area to evaluate the different strategies for disposal of wastewater are presented.

Download Full-text

Analysis of the reproduction mode in Psidium spp. using the pollen:ovule ratio

Acta Scientiarum Agronomy ◽

10.4025/actasciagron.v43i1.44062 ◽

2020 ◽

Vol 43 ◽

pp. e44062

Author(s):

Maria Lorraine Fonseca Oliveira ◽

Telma Nair Santana Pereira ◽

Rodrigo Miranda Barbosa ◽

Alexandre Pio Viana

Keyword(s):

Pollen Grains ◽

Flower Bud ◽

Reproduction Mode ◽

Reproductive Characteristics ◽

Reproduction Strategy ◽

Pollen:Ovule Ratio ◽

Floral Bud

This research aimed to explore the reproductive characteristics of three species of Psidium (P. guajava L., P. cattleyanum Sabine, and P. guineense Sw.) and estimate a probable reproduction strategy based on the pollen:ovule (P:O) methodology. The number of pollen grains per floral bud (NGPB), number of pollen grains per anther (NGPA), number of anthers per flower bud (NAB), number of ovules per flower bud (NOB), and the P:O ratio of each species were estimated. All species had a P:O ratio over 2,000 and were classified as xenogamous. P.guajava presented the highest values for all characteristics evaluated, with the NGPB at 3,777,519, the NOB at 584.50 and a P:O ratio of 6,462.82. Similarly, P. cattleyanum had a P:O ratio of 5,649.89 (NGPB 762,736 and NOB 135). However, P. guineense was considered facultative xenogamous, with P:O of 2,085.75, the NGPB at 741,484 and the NOB at 355.50. Thus, it was concluded that the studied species have a preference for allogamy and require many pollen grains to fertilize each ovule, demonstrating that the transfer of pollen to the stigma is not very specialized.

Download Full-text