Influence of 17β-oestradiol (E2) and 17α-hydroxyprogesterone (OHP) on ovarian maturation in Penaeus semisulcatus De Haan, 1844 (Decapoda, Dendrobranchiata, Penaeidae) from the Mediterranean Sea off Alexandria, Egypt

Crustaceana ◽  
2021 ◽  
Vol 94 (8) ◽  
pp. 903-932
Author(s):  
Ibrahim Gaber ◽  
Oleg Latyshev
Keyword(s):  
Mediterranean Sea ◽  
Steroid Hormones ◽  
Maximum Temperature ◽  
Basal Cells ◽  
Ovarian Maturation ◽  
High Concentration ◽  
Spawning Period ◽  
Gonadal Maturation ◽  
Penaeus Semisulcatus ◽  
The Mediterranean

Abstract This study searches to provide appropriate conditions to trigger spawning in Penaeus semisulcatus in aquaculture. The aim was to test the effect of 17β-oestradiol and 17α-hydroxyprogesterone on ovarian maturation and to study the correlation between the different stages of ovarian maturation and hormonal levels in the ovaries, hepatopancreas, and haemolymph. Female shrimps were collected from Ras El-Tin beach and the fishing port to Abu Qir Bay of the Mediterranean Sea off Alexandria, Egypt from June 2018-August 2019. Shrimps were individually weighed and subsequently killed by thermal shock at a maximum temperature of 45°C. Gonadosomatic and hepatosomatic indices were calculated. The correlation between the gonadosomatic and hepatosomatic indices indicates the presence of endogenous and exogenous vitellogenesis. The haemolymph, hepatopancreas, and ovaries were studied by stereo- and electron microscopy. From 15 females in each season the mentioned tissues were isolated for the extraction and quantification of steroid hormones during the different stages of gonadal maturation using radioimmunoassay. An ecdysteroid- and steroid-extraction protocol was applied. Aliquots were collected from the haemolymph to identify 17β-oestradiol and 17α-hydroxyprogesterone by mass spectrometry. Five stages of gonadal maturation were observed. The hepatopancreas was formed by a set of tubules lined with pseudostratified epithelium composed of five cell types, cell E (undifferentiated), cell F (fibrillar), cell B (vesicular), R (reabsorbing), and M (basal) cells. Steroidogenic tissues were small in size and numerous. The ultrastructure of the ovary and hepatopancreas were studied during oocyte development. There was a high concentration of 17β-oestradiol and 17α-hydroxyprogesterone in stages I and II of ovarian maturation, coinciding with the preparation phase for vitellogenesis. A progressive decrease of these steroid hormones occurred during the course of gonadal maturation, and reached its lowest concentration in the spawning period. The ecdysone concentration did not fluctuate in ripe females. Its level increases from stages I-IV of vitellogenesis onward.

Morphological response of the larvae of Arbacia lixula to near-future ocean warming and acidification

2017 ◽  
Vol 74 (4) ◽  
pp. 1180-1190 ◽  
Author(s):  
Giulia Visconti ◽  
Fabrizio Gianguzza ◽  
Emanuela Butera ◽  
Valentina Costa ◽  
Salvatrice Vizzini ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Larval Development ◽  
Thermal Tolerance ◽  
Population Connectivity ◽  
Mediterranean Population ◽  
Spawning Period ◽  
Increased Temperature ◽  
The Mediterranean ◽  
The Impact ◽  
Arbacia Lixula

The distribution of the sea urchin Arbacia lixula, a warm affinity species, has been expanding in the Mediterranean Sea. To address questions on potential for future success of this species in the region, the thermotolerance of larval development was investigated in context of regional warming. The larvae were reared in present day spawning period (20 °C) and warming conditions (+4 = 24 and +6 = 26 °C). As the calcifying larvae of sea urchins are vulnerable to stunted growth caused by ocean acidification, the impact of lower pH (−0.3 pH units) on larval development was also investigated in combination with warming. Morphological traits of the larvae, post-oral length arms, overall length of larvae and body length, were affected by increased temperature across pH treatments, indicating that for the larvae of southern Mediterranean population here, 24 °C appears to approximate the optimal temperature for development. A slightly negative effect of pH was evident. Increased temperature ameliorated the stunting effect of acidification on growth. The thermal tolerance of A. lixula development overlaps with projections for warming in the region by 2100 and also indicates that this species has acclimatized or adapted its reproductive biology to the broad environmental conditions of the Mediterranean Sea. Due to the broad thermal range (∼10 °C) of development of A. lixula across its distribution, this species is likely to be a winner in the climate change stakes. The broad thermal tolerance of the larvae is likely to assure population connectivity between Mediterranean sub-basins populations. The continued success of A. lixula can have a strong consequences for the ecological structure of Mediterranean rocky habitat.

Aeromonas dhakensis pneumonia and sepsis in a neonate Risso’s dolphin Grampus griseus from the Mediterranean Sea

2015 ◽  
Vol 116 (1) ◽  
pp. 69-74 ◽  
Author(s):  
L Pérez ◽  
ML Abarca ◽  
F Latif-Eugenín ◽  
R Beaz-Hidalgo ◽  
MJ Figueras ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Grampus Griseus ◽  
The Mediterranean ◽  
Risso's Dolphin

Dolphin Morbillivirus in the Mediterranean Sea

2008 ◽  
Vol 34 (4) ◽  
pp. 514-515 ◽  
Author(s):  
Giovanni Di Guardo
Keyword(s):  
Mediterranean Sea ◽  
Dolphin Morbillivirus ◽  
The Mediterranean

The Mediterranean Action Plan: A Regional Approach to Pollution Control

1986 ◽  
Vol 18 (9) ◽  
pp. 197-205
Author(s):  
Lj Jeftié ◽  
L. J. Saliba
Keyword(s):  
Mediterranean Sea ◽  
Action Plan ◽  
Control Measures ◽  
Industrial Wastes ◽  
Pollution Monitoring ◽  
Environmental Preservation ◽  
Agricultural Pesticides ◽  
The Mediterranean ◽  
A Prospective Study ◽  
And Control

Increasing concern over the deterioration of the Mediterranean sea as a result of increasing pollution by untreated sewage and industrial wastes, agricultural pesticides and fertilizers and oil discharges, led to a series of meetings between 1970 and 1974, and finally to the UNEP-sponsored Mediterranean Action Plan, adopted by governments of the region in 1975 and ongoing since that time. The legal component of the Plan includes a framework Convention and four protocols; the environmental assessment component (the MED POL programme) consists of national pollution monitoring programmes, and research projects conducted by Mediterranean institutions; the environmental management component consists of the Blue Plan (a prospective study combining socio-economic development with environmental preservation) and the Priority Actions Programme (a series of sub-region sectoral projects in defined areas). The Plan has been financed by Mediterranean States since 1979, and is managed by UNEP with the cooperation of other competent UN Agencies. During the last ten years, activities undertaken have improved knowledge of the state of pollution of the Mediterranean sea, and facilitated joint regional action in the form of preventive and control measures.

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