Background: In this study, we report the first case of a male reef manta ray, Mobula alfredi, becoming sexually mature in captivity and present its reproductive characteristics. Methods: We investigated changes in external morphology, behavior, and levels of steroid hormones in a male M. alfredi during its sexual maturation process. Results: At 2 years and 6 months of age, the male exceeded 300...

The orthodontic treatment is most favorable and effective during growth and hence the assessment of growth is significant in treatment planning for dental and maxillofacial malocclusion [1,2]. Several features such as body height, weight and sexual characteristics, dental and skeletal development are used to evaluate the pubertal growth. The stage of tooth maturation can determine the dental ma...

Early and regular blood transfusion therapy in patients with homozygous beta-thalassemia decreases the complications of severe anemia and prolongs survival. In the long term, however, the beneficial effects of transfusions are limited by the organ damage resulting from iron overload. Endocrine complications in patients with thalassemia major in developing countries may be frequent due t o ...

data related to yazd native fowls (obtained during 2000-2008) yazd native fowls were made use of in the present study. the investigated traits consisted of body weight at 8 (bw8) and 12 weeks (bw12), age at sexual maturity (asm), egg number during the first three months of production period (en) and the mean egg weight at 28, 30 and 32 weeks of age (ew). the genetic and phenotypic parameters we...

BACKGROUND Few human studies have evaluated the impact of childhood exposure to organochlorine pesticides (OCP) on pubertal development. OBJECTIVE We evaluated associations of serum OCP concentrations [hexachlorobenzene (HCB), β-hexachlorocyclohexane (βHCH), and p,p-dichlorodiphenyldichloroethylene (p,p´-DDE)] with age at attainment of sexual maturity among boys. METHODS From 2003 through 2...

Mutagenic and epigenetic effects of environmental stressors and their transgenerational consequences are of interest to evolutionary biologists because they can amplify natural genetic variation. We studied the effect of parental exposure to radioactive contamination on offspring development in lesser marsh grasshopper Chorthippus albomarginatus. We used a geometric morphometric approach to mea...

Climate change modelers predict increasingly frequent "extreme events," so it is critical to quantify whether organismal responses (such as reproductive output) measured over the range of usual climatic conditions can predict responses under more extreme conditions. In a 20-year field study on water pythons (Liasis fuscus), we quantified the effects of climatically driven annual variation in fo...

The testicular growth of guinea-fowls in relation to age was compared under 3 constant photoperiods (7L: 17D; 14L: 10D; 20L: 4D) from 3 weeks of age. Although long daylength (14L or 20L) caused precocious development of the gonads, it also limited total adult gonadal weight to around 1 800 +/- 200 mg. Short daylengths (7L) delayed the development of the gonads but their adult weight was enhance...