Sexual dimorphism and morphometric relationships in pelvic bones of Commerson's dolphins (Cephalorhynchus c. commersonii) from Tierra del Fuego, Argentina

2014 ◽  
Vol 31 (2) ◽  
pp. 734-747 ◽  
Author(s):  
Iris Cáceres-Saez ◽  
Natalia A. Dellabianca ◽  
Lida E. Pimper ◽  
Federico Pereyra-Bonnet ◽  
Guillermo Hernán Cassini ◽  
...  
2006 ◽  
Vol 63 (1) ◽  
pp. 105-116 ◽  
Author(s):  
Natalia L. Ruocco ◽  
Luis O. Lucifora ◽  
Juan M. Díaz de Astarloa ◽  
Otto Wöhler

AbstractSize at maturity, sexual dimorphism, gonad development, and abundance of white-dotted skate, Bathyraja albomaculata, were assessed along its geographic range in the Southwest Atlantic, from Uruguay to Tierra del Fuego (Argentina). In all, 291 specimens from eight research cruises conducted between 1998 and 2003 were examined. Length–mass relationships were sexually dimorphic, adult females being significantly heavier than males of the same length. The largest female observed was 762 mm total length (LT), and 50% maturity (LT50) was attained at 653 mm LT. The largest male was 732 mm LT, and male LT50 was 628 mm LT. Female and male LT50 were not significantly different and were about 86% of observed maximum size, similar to other Bathyraja species. The lack of sexual dimorphism in size at maturity and the slight difference in maximum size between sexes support the hypothesis of relaxation of selection for large female size in oviparous elasmobranchs. Liver size was not sexually dimorphic. Mature female gonads were symmetrical in terms of mass, and similar in ovarian follicle number and size. Females carried egg cases in April, September, and October, consistent with previous observations around the Islas Malvinas and suggesting year-round egg laying. Bathyraja albomaculata was most abundant on the outer continental shelf and slope between 36°30′S and 45°S (northern area). In contrast, it was generally absent between 48°S and 52°S (southern area), a region where it was formerly reported as abundant. These differences are coincident with the development of a fishery targeting skates in the southern area, whereas in the north B. albomaculata taken as bycatch are mostly discarded alive.


1968 ◽  
Vol 07 (01) ◽  
pp. 28-36 ◽  
Author(s):  
Władysław Jasiński ◽  
Janina Malinowska ◽  
Henryk Mackiewicz ◽  
Henryk Siwicki ◽  
Krystyna Lukawska

SummaryThe purpose of this investigation was to study the accumulation of 87mSr in the proximal parts of the femoral bones of patients treated previously by external irradiation due to cancer of the uterine cervix. It was assumed that this method may be used in the future for the early diagnosis of postirradiation changes of bone (osteoradionecrosis).The incidence of postirradiation changes of the femoral neck among 5735 patients treated between 1950 and 1961 at the Department of Gynaecology of the Institute, was 0.8%. In the early period of postirradiation changes the patients complain only of pain and limitation of physical activities. If radiological and gynaecological findings were negative, the differential diagnosis between early recurrence and early osteoradionecrosis became impossible.49 selected patients were scanned after intravenous injection of 10—115 μCi of 87mSr per kg of body weight (0.5 up to 6.0 mCi). Illustrative cases of normal pelvic bones as well as postirradiation changes are presented and discussed. The authors conclude that the findings justify further systematic studies on the morphology of accumulation of 87mSr in the bones.


Author(s):  
I. R. Khuzina ◽  
V. N. Komarov

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.


2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.


2019 ◽  
Author(s):  
Marcia Hiriart ◽  
Myrian Velasco ◽  
Marcia Hiriart

Sign in / Sign up

Export Citation Format

Share Document