scholarly journals Protandric hermaphroditism in the bivalve Arca noae (Mollusca: Arcidae)

2013 ◽  
Vol 14 (1) ◽  
pp. 86 ◽  
Author(s):  
G. BELLO ◽  
P. PAPARELLA ◽  
A. CORRIERO ◽  
N. SANTAMARIA
Keyword(s):  
Germ Cells ◽  
Histological Analysis ◽  
Adriatic Sea ◽  
Sex Change ◽  
The South ◽  
Male And Female ◽  
Protandric Hermaphroditism ◽  
Male To Female ◽  
Theoretical Considerations

Following the histological analysis of Arca noae samples from the south-western Adriatic Sea, five hermaphroditic specimens were found out of 168 sexed individuals (3.0%). The hermaphrodite gonads showed the co-occurrence of male and female germ cells within the same acini, i.e. both spermatozoa in the lumen and oogonia lining its wall. Oogonia increased in size through winter, thus suggesting that the direction of sex change is from male to female. Both the biometrical analyses and theoretical considerations strongly suggest that A. noae is an obligate protandric species.

scholarly journals The presence of Tetraodontidae species in the Central Mediterranean

2017 ◽  
Vol 58 (2) ◽  
pp. 325-336 ◽  
Author(s):  
Pierluigi Carbonara ◽  
Maria Teresa Spedicato ◽  
Nicoletta Milone ◽  
Guliem Kroqi ◽  
Zdravko Ikica ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Stomach Contents ◽  
First Record ◽  
The South ◽  
Central Mediterranean ◽  
Male And Female ◽  
Stomach Contents Analysis ◽  
Post Spawning ◽  
Lagocephalus Sceleratus ◽  
Established Population

This paper presents the first record of the Lessepsian migrant fish Lagocephalus sceleratus (silver-cheeked toadfish) on the Italian side of the south Adriatic Sea. In addition, four specimens of Sphoeroides pachygaster (blunthead puffer) were analysed. Meristic and morphometric data of the silver-cheeked toadfish and blunthead puffer are in accordance with data from the Mediterranean. The specimen of silver-cheeked toadfish was a female with gonad in resting stage and the specimens of blunthead puffer were adults (male and female) with gonads in maturing, mature/spawner and post-spawning stage. The stomach contents of the specimen of silver-cheeked toadfish were composed by Mollusca Opistobranchia and Crustacea Brachyura. Stomach contents analysis of S. pachygaster confirmed that Mollusca are the preferred prey for this species. However, the presence of Crustacea (shrimps, crabs) and fish in the stomachs indicates that the blunthead puffer has a broad and variable diet in the south Adriatic Sea. The present study suggests the presence of an established population of blunthead puffer on the continental shelf of the southeast Adriatic Sea.

scholarly journals Reproductive Isolation and Morphogenetic Evolution in Drosophila Analyzed by Breakage of Ethological Barriers

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Lucas Sánchez ◽  
Pedro Santamaria
Keyword(s):  
Reproductive Isolation ◽  
Germ Cells ◽  
Morphological Analysis ◽  
Seminal Fluid ◽  
Germ Line ◽  
Regulatory Gene ◽  
Motile Sperm ◽  
Male And Female ◽  
Drosophila Yakuba

Abstract This article reports the breaking of ethological barriers through the constitution of soma-germ line chimeras between species of the melanogaster subgroup of Drosophila, which are ethologically isolated. Female Drosophila yakuba and D. teissieri germ cells in a D. melanogaster ovary produced functional oocytes that, when fertilized by D. melanogaster sperm, gave rise to sterile yakuba-melanogaster andteissieri-melanogaster male and female hybrids. However, the erecta-melanogaster and orena-melanogaster hybrids were lethal, since female D. erecta and D. orena germ cells in a D. melanogaster ovary failed to form oocytes with the capacity to develop normally. This failure appears to be caused by an altered interaction between the melanogaster soma and the erecta and orena germ lines. Germ cells of D. teissieri and D. orena in a D. melanogaster testis produced motile sperm that was not stored in D. melanogaster females. This might be due to incompatibility between the teissieri and orena sperm and the melanogaster seminal fluid. A morphological analysis of the terminalia of yakuba-melanogaster and teissieri-melanogaster hybrids was performed. The effect on the terminalia of teissieri-melanogaster hybrids of a mutation in doublesex, a regulatory gene that controls the development of the terminalia, was also investigated.

Dynamics of Prokaryotic Community in the Montenegrin Part of the South Adriatic Sea

2021 ◽  
Author(s):  
Aleksandra Huter ◽  
Dragana Drakulović ◽  
Sandra Jokanović
Keyword(s):  
Adriatic Sea ◽  
Prokaryotic Community ◽  
The South

scholarly journals The earliest example of sexual dimorphism in bivalves—evidence from the astartid Nicaniella (Lower Jurassic, southern Germany)

2021 ◽  
pp. 1-10
Author(s):  
Baran Karapunar ◽  
Winfried Werner ◽  
Franz T. Fürsich ◽  
Alexander Nützel
Keyword(s):  
Principal Component Analysis ◽  
Life History ◽  
Shape Analysis ◽  
Principal Component ◽  
Sex Change ◽  
Lower Jurassic ◽  
Allocation Of Resources ◽  
Fourier Shape Analysis ◽  
Lower Height ◽  
Male To Female

Abstract Protandrous sex change (sex change from male to female) is one of the diverse sexual expressions exhibited by bivalves, but its expression in the shell is quite rare. Previous studies on living and fossil astartids suggest a relationship between protandrous sex change and the formation of crenulations on the ventral shell margin at later ontogenetic stages. Here we report the formation of such crenulations in the Early Jurassic astartid Nicaniella rakoveci (Kuhn, 1935) from the Amaltheenton Formation at Buttenheim, Franconia. This is the earliest known record of protandrous hermaphroditism in fossil bivalves, predating previous reports by at least 13 Myr. A principal component analysis of linear size measurements and Fourier shape analysis of the shell outlines revealed that the outline of Nicaniella rakoveci specimens varies from subquadrate to subcircular, but this variation is independent of the presence or absence of crenulations and therefore not associated with sex. Crenulated specimens exhibit a lower height/inflation ratio than non-crenulated ones, suggesting that the protandrous females have more inflated valves than the males. The formation of crenulations was probably related to allocation of resources for reproduction. The most likely function of the crenulations was to increase the internal shell volume in the female stage to accommodate more eggs rather than being an adaptation against predation as often assumed for other bivalves. The formation of crenulations is part of the protandrous life history and probably is controlled by a genetic mechanism that is also responsible for sex change.

scholarly journals The Risk of Partner Aggression Research: Impact of Laboratory Couples Conflict Protocols on Participants

2006 ◽  
Vol 21 (4) ◽  
pp. 483-497 ◽  
Author(s):  
Daniela J. Owen ◽  
Richard E. Heyman ◽  
Amy M. Smith Slep
Keyword(s):  
Intimate Partner Violence ◽  
Partner Violence ◽  
Research Impact ◽  
Intimate Partner ◽  
Partner Aggression ◽  
Male And Female ◽  
Impact Measure ◽  
The Impact ◽  
Male To Female ◽  
Couples Conflict

The impact of male-to-female intimate partner violence (IPV) research on participants is unknown. A measure of impact was given to participants in an IPV study to assess systematically the impact of completing questionnaires, engaging in conflict conversations, and being interviewed individually about anger escalation and de-escalation during the conversations. Participants completed a six-question, Likert-scaled impact measure. Both male and female participants rated the impact of the study as helpful to them personally and to their relationships. Female participants rated different segments of the study as more helpful to themselves and their relationships, while male participants did not find any segment of the study to have a different impact than other segments.

Systematic revision and cladistic analysis of the South American genus Endeius Coiffait & Sáiz (Coleoptera: Staphylinidae)

2008 ◽  
Vol 39 (4) ◽  
pp. 381-406 ◽  
Author(s):  
Mariana Chani-Posse de Maus
Keyword(s):  
Cladistic Analysis ◽  
Identification Key ◽  
External Morphology ◽  
Female Genitalia ◽  
Valid Species ◽  
South American ◽  
The South ◽  
Systematic Revision ◽  
Male And Female

AbstractThe genus Endeius Coiffait & Sáiz, 1968 (Staphylininae: Staphylinini), distributed from Chile and Argentina through Juan Fernández Is. and Galapagos Is., is revised using characters of external morphology and male and female genitalia. Endeius comprises seven valid species: E. punctipennis (Solier), E. nitidipennis (Solier), E. subpunctipennis Coiffait & Sáiz, E. loensis Coiffait & Sáiz, E. franzi Sáiz, E. lugubris Sáiz and E. ovaliceps Coiffait. Belonuchus multipunctatus (Coiffait), comb. nov., is excluded from Endeius. An identification key to all species of the genus is provided. Monophyly of Endeius, as considered in the present study, is supported by one synapomorphy from the external morphology. Within the genus, the best supported subgroup consists of E. punctipennis (Solier), E. subpunctipennis Coiffait & Sáiz, E. loensis Coiffait & Sáiz and E. ovaliceps Coiffait.

scholarly journals The developing ovary of the South American plains vizcacha, Lagostomus maximus (Mammalia, Rodentia): massive proliferation with no sign of apoptosis-mediated germ cell attrition

Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 633-641 ◽  
Author(s):  
N P Leopardo ◽  
F Jensen ◽  
M A Willis ◽  
M B Espinosa ◽  
A D Vitullo
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Tissue ◽  
Tunel Assay ◽  
South American ◽  
Follicular Atresia ◽  
The South ◽  
Cell Degeneration ◽  
Lagostomus Maximus ◽  
Apoptotic Activity

Apoptosis-dependent massive germ cell death is considered a constitutive trait of the developing mammalian ovary that eliminates 65–85% of the germinal tissue depending on the species. After birth and during adult lifetime, apoptotic activity moves from the germ cell proper to the somatic compartment, decimating germ cells through follicular atresia until the oocyte reserve is exhausted. In contrast, the South American rodent Lagostomus maximus shows suppressed apoptosis-dependent follicular atresia in the adult ovary, with continuous folliculogenesis and massive polyovulation, which finally exhausts the oocyte pool. The absence of follicular atresia in adult L. maximus might arise from a failure to move apoptosis from the germinal stratum to the somatic compartment after birth or being a constitutive trait of the ovarian tissue with no massive germ cell degeneration in the developing ovary. We tested these possibilities by analysing oogenesis, expression of germ cell-specific VASA protein, apoptotic proteins BCL2 and BAX, and DNA fragmentation by TUNEL assay in the developing ovary of L. maximus. Immunolabelling for VASA revealed a massive and widespread colonisation of the ovary and proliferation of germ cells organised in nests that disappeared at late development when folliculogenesis began. No sign of germ cell attrition was found at any time point. BCL2 remained positive throughout oogenesis, whereas BAX was slightly detected in early development. TUNEL assay was conspicuously negative throughout the development. These results advocate for an unrestricted proliferation of germ cells, without apoptosis-driven elimination, as a constitutive trait of L. maximus ovary as opposed to what is normally found in the developing mammalian ovary.

Development of the germ cells and reproductive primordia in male and female embryos of Rhodnius prolixus Stål (Hemiptera: Reduviidae)

1994 ◽  
Vol 72 (6) ◽  
pp. 1100-1119 ◽  
Author(s):  
B. S. Heming ◽  
E. Huebner
Keyword(s):  
Germ Cells ◽  
Dorsal Surface ◽  
Interstitial Cells ◽  
Rhodnius Prolixus ◽  
Posterior Pole ◽  
Male And Female ◽  
Functional Aspects ◽  
Pole Plasm ◽  
Blastodermal Cells ◽  
Sheath Cells

Newly deposited eggs of Rhodnius prolixus lack a visible pole plasm and require 14 days to develop at 27 °C and 70% RH. The first germ cells originate at 9% of embryogenesis by asynchronous mitosis of blastodermal cells behind the germ Anlage at the posterior pole of the egg. From 9 to 17%, these proliferate to a mean of 270 cells and, from 13 to 18%, migrate forward over the dorsal surface of the mesoderm and lodge in abdominal segments 3–7. Between 22 and 30%, they shift laterally and segregate into three or four paired clumps between segments 3 and 4, 4 and 5, 5 and 6, and, sometimes, 6 and 7 and, from 30 to 37%, gradually assemble into a continuous longitudinal mass on either side of segments 3–6, where they begin to associate with mesodermal cells. Between 37 and 46%, these collect between (males) and around the germ cells to form the rudiments of the terminal filaments (females), inner and outer gonadal sheaths, interstitial cells (males), and primary exit ducts. Dorsally situated sheath cells then invaginate ventrally into each gonadal rudiment, partitioning it into seven compartments, each containing a mean of 15 oogonia or 16 spermatogonia. These seem to fuse into a rosette, at least in females, but do not begin to divide again until after hatch. Excluded germ cells lodge within the rudiments of one or both exit ducts. The evolutionary and functional aspects of our findings are addressed and new observations are presented on the mechanism of anatrepsis.

scholarly journals Operability Guidelines For Product Tanker In Heavy Weather In The Adriatic Sea

2014 ◽  
Vol 21 (1) ◽  
pp. 95-106
Author(s):  
Luka Mudronja ◽  
Marko Katalinić ◽  
Rino Bošnjak ◽  
Pero Vidan ◽  
Joško Parunov
Keyword(s):  
Wave Height ◽  
Adriatic Sea ◽  
Wave Spectrum ◽  
Extreme Weather ◽  
The South ◽  
Sea State ◽  
M Wave ◽  
The North ◽  
Limiting Values ◽  
Deck Wetness

AbstractThis paper presents operability guidelines for seafarers on a product tanker which navigates in the Adriatic Sea during heavy weather. Tanker route starts from the Otranto strait in the south to the island Krk in the north of Adriatic Sea. Heavy weather is caused by south wind called jugo (blowing from E-SE to SS-E, sirocco family). Operability guidelines are given based on an operability criteria platform for presenting ship seakeeping characteristics. Operability criteria considered in this paper are propeller emergence, deck wetness and bow acceleration of a product tanker. Limiting values of mentioned criteria determine sustainable speed. Heavy weather is described by extreme sea state of 7.5 m wave height. Wave spectrum used in this paper is Tabain spectrum which is developed specifically for Adriatic Sea. Seafarer's approach of decisions making in extreme weather is also shown and servers as a guideline for further research of the authors.

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