scholarly journals Determination of sexual dimorphism using morphometric techniques in Rachycentron canadum (Perciformes: Rachycentridae) cultivated in captivity

2021 ◽  
Vol 50 (1) ◽  
pp. 79-90
Author(s):  
Roy González ◽  
Adriana Bermúdez ◽  
Gabriel Navas
Keyword(s):  
Sexual Dimorphism ◽  
High Growth ◽  
Cage Culture ◽  
General Shape ◽  
Rachycentron Canadum ◽  
In Captivity ◽  
Environmental Variations ◽  
Apparent Similarity ◽  
Important Fish

Rachycentron canadum is an economically important fish in aquaculture due to its resistance to environmental variations, the feasibility of culture in confinement, high growth rates, and good acceptance by consumers. The profitability of their cage culture is negatively affected by the difficulty of implementing monosex cultures due to the apparent similarity between sexes. In this study, morphometric techniques were used to determine sexual dimorphism by analyzing measurements and the fish’s shape. Differences were found between the sexes in the position of the eyes, lips, pectoral fin and ventral fin, and the body’s general shape. The sexing precision of the individuals was 75.4 % with distances and 82.7 % with geometric morphometry.

scholarly journals Effect of temperature on growth of the threatened annual fish Austrolebias nigrofasciatus Costa & Cheffe 2001

2012 ◽  
Vol 12 (4) ◽  
pp. 68-73 ◽  
Author(s):  
Matheus Vieira Volcan ◽  
Alinca Peres da Fonseca ◽  
Mário Roberto Chim Figueiredo ◽  
Luís André Sampaio ◽  
Ricardo Berteaux Robaldo
Keyword(s):  
Growth Rate ◽  
Sexual Dimorphism ◽  
Effect Of Temperature ◽  
Initial Growth ◽  
Southern Brazil ◽  
Annual Fish ◽  
Annual Killifish ◽  
In Captivity ◽  
Final Length

This study evaluated the effect of temperature on growth of Austrolebias nigrofasciatus, an endemic and threatened annual killifish species of the Patos-Mirim lagoon system in Southern Brazil. In order to verify the effect of temperature on initial growth of A. nigrofasciatus, eggs stored in the laboratory were hatched and juveniles reared for eight weeks at 16 and 22 ºC. The standard length of newly hatched fishes was 4.67 ± 0.25 mm and after eight weeks they reached 23.68 ± 3.73 and 22.68 ± 5.36 mm, respectively at 16 and 22 ºC. However, initial growth of fish reared at 22 ºC was faster and they reached sexual dimorphism at an earlier age compared to those reared at 16 ºC. Final length of females reared at 22 ºC was 23.00 ± 2.83 mm, they were significantly larger than those reared at 16 ºC (17.91 ± 2.47 mm). Males were significantly larger than the females at 16 ºC, but there was no difference for growth between sexes of fish reared at 22 ºC. The sex ratios were 1:0.6 and 1:1.1 (M:F) at 16 ºC and 22 ºC, respectively, suggesting temperature determination of phenotypic sex. Considering the results, it appears that juveniles to be developed in captivity should be kept at 22 ºC during the first six weeks of life, thus ensuring a higher growth rate until puberty.

scholarly journals Effect of captivity on morphology: negligible changes in external morphology mask significant changes in internal morphology

2018 ◽  
Vol 5 (5) ◽  
pp. 172470 ◽  
Author(s):  
Stephanie K. Courtney Jones ◽  
Adam J. Munn ◽  
Phillip G. Byrne
Keyword(s):  
Sexual Dimorphism ◽  
Captive Breeding ◽  
Morphological Changes ◽  
External Morphology ◽  
Wild Animals ◽  
Internal Morphology ◽  
In Captivity ◽  
Two Generations ◽  
Breeding Programmes ◽  
Source Populations

Captive breeding programmes are increasingly relied upon for threatened species management. Changes in morphology can occur in captivity, often with unknown consequences for reintroductions. Few studies have examined the morphological changes that occur in captive animals compared with wild animals. Further, the effect of multiple generations being maintained in captivity, and the potential effects of captivity on sexual dimorphism remain poorly understood. We compared external and internal morphology of captive and wild animals using house mouse ( Mus musculus ) as a model species. In addition, we looked at morphology across two captive generations, and compared morphology between sexes. We found no statistically significant differences in external morphology, but after one generation in captivity there was evidence for a shift in the internal morphology of captive-reared mice; captive-reared mice (two generations bred) had lighter combined kidney and spleen masses compared with wild-caught mice. Sexual dimorphism was maintained in captivity. Our findings demonstrate that captive breeding can alter internal morphology. Given that these morphological changes may impact organismal functioning and viability following release, further investigation is warranted. If the morphological change is shown to be maladaptive, these changes would have significant implications for captive-source populations that are used for reintroduction, including reduced survivorship.

scholarly journals Adjacent digit fingerprint white line count differences: a pointer to sexual dimorphism for forensic application

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Magaji Garba Taura ◽  
Lawan Hassan Adamu ◽  
Abdullahi Yusuf Asuku ◽  
Kabiru Bilkisu Umar ◽  
Musa Abubakar
Keyword(s):  
Logistic Regression ◽  
Sexual Dimorphism ◽  
Binary Logistic Regression ◽  
Stepwise Logistic Regression ◽  
Regression Analyses ◽  
Forensic Application ◽  
White Line ◽  
Study Population ◽  
Right And Left Hands

Abstract Background Sex determination is one of the leading criterion in identification and verification of an individual. However, the potential roles of differences in adjacent fingerprint white line count (FWLC) in sex inference are not well elucidated in the literature especially among Hausa population. The study was conducted to determine sexual dimorphism and predict sex using adjacent digit FWLC difference (adj. DFWLCD) among Hausa population of Kano state, Nigeria. Methods The study population involved 300 participants. FWLC was determined from a plain fingerprint captured using live scanner. The formula for adj. DFWLCD of thumb and fifth digit is dR15 for right hand. The same applied for possible combination in cephalocaudal direction. Mann-Whitney and t tests were used for comparison of variables between sexes. Binary logistic regression analyses were employed for determination of sex. Results We observed a significantly larger adj. DFWLCD in males compared with females in most of the digit combination. A significant sexual dimorphism was observed in most of the adj. DFWLCD involving ring digit in both right (dR14, dR24, and dR34) and left (dL14, dL24, and dL34). The best discrimination was observed in adjacent FWLC difference of second and fourth digits in both right and left digits (dR24 and dL24). This was further supported by stepwise logistic regression analyses. Conclusion The adj. DFWLCD exhibits sexual dimorphism. The best prediction potentials were found to be dR24 and dL24 for right and left hands respectively.

scholarly journals Determination of sexual dimorphism via maxillary first molar teeth in Himachali population

2015 ◽  
Vol 7 (2) ◽  
pp. 90
Author(s):  
Swati Singla ◽  
Rakhi Gupta ◽  
Abhiney Puri ◽  
Sucheta Bansal ◽  
Smita Singla ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Molar Teeth

scholarly journals SEXUAL DIMORPHISM IN PSEUDOPUS APODUS (REPTILIA: SAURIA: ANGUIDAE) FROM THE STEPPE CRIMEA

2018 ◽  
Vol 19 ◽  
pp. 1-21
Author(s):  
Oleg V. Kukushkin ◽  
Igor V. Dovgal
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Parameters ◽  
The Body ◽  
Body Proportions ◽  
Reliable Determination ◽  
Kerch Peninsula ◽  
The Crimea ◽  
Males And Females ◽  
Almost All

The current paper is focused on sexual dimorphism of a giant glass lizard, or sheltopusik, Pseudopus apodus apodus (Pallas, 1775) from its northernmost populations inhabiting the Crimea. In total, 72 P. apodus individuals (45 males and 27 females) were collected at the Kerch Peninsula during 2013–2017. To estimate the variability, 13 morphometric parameters and 18 indices characterizing the head and body proportions were used. It was found that males and females differed significantly by means of almost all parameters, except the body and tail sizes. Besides that, the differences by 10 ratios characterizing head proportions were revealed as well. However, a reliable determination of the lizard sex using linear sizes and/or ratios values seems to be impossible because of the strong overlap of the variability ranges in both sexes. At the same time, the use of the canonical discriminant analysis by the complex of morphometric parameters and by ratios has shown that the males and females in both datasets are classified correctly basing on the sex with an accuracy approximating 100%. The differences in the allometric growth of males and females partially define the sexual dimorphism of P. apodus on head size and shape. A sex-related differences in the development of at least one pair of parameters (head and snout lengths) were clearly evident, since isometry was established for males, while allometry ‒ for females. Moreover, the systems of correlation between the body and head parts differ in both sexes. Thus, male characterisitics correlate significanly, while the female ones were less toughly connected, and some pairs of parameters did not correlate at all.

Ecological and economic analysis for cobia Rachycentron canadum commercial cage culture in Taiwan

2008 ◽  
Vol 17 (2) ◽  
pp. 125-141 ◽  
Author(s):  
Sha Miao ◽  
Chen Cheun Jen ◽  
Cheng Ting Huang ◽  
Sing-Hwa Hu
Keyword(s):  
Economic Analysis ◽  
Cage Culture ◽  
Rachycentron Canadum

scholarly journals Determination of Hematological Values of Common Crocodile (Caiman Crocodilus fuscus) in Captivity in the Magdalena medio of Colombia

2020 ◽  
Vol 25 (1) ◽  
pp. 75-81
Author(s):  
Juana Valentina Grijalba Otálora ◽  
Ekin Josué Forero Rojas ◽  
Angie Fernanda Contreras ◽  
Julio Cesar Vargas ◽  
Roy Jose Andrade
Keyword(s):  
Blood Cells ◽  
Hemoglobin Concentration ◽  
Good Health ◽  
Corpuscular Volume ◽  
Corpuscular Hemoglobin ◽  
Blood Samples ◽  
Caiman Crocodilus ◽  
In Captivity ◽  
Hematological Values

Caiman zoo breeding (Caiman crocodilus fuscus) has been developing with greater force in Colombia since the 90s. It is essential to evaluate the physiological ranges of the species to be able to assess those situations in which their health is threatened. The objective of the present study was to determine the typical hematological values of the Caiman (Caiman crocodilus fuscus) with the aid of the microhematocrit, the cyanmethemoglobin technique, and a hematological analyzer. The blood samples were taken from 120 young animals of both sexes in good health apparently (males 44 and females 76). The samples were taken from the coccygeal vein between the second and third interscalar space with lilac lid vacutainer tube whit acid ethylene-diamine-tetra-acetic as an anticoagulant. The animals are located in the middle of the Magdalena area in Colombia. The results obtained on average were Hematocrit: 23.36 %, Hemoglobin: 7.78 g/dl, Red blood cells: 3.89 106/μL, Average corpuscular volume: 60 fl, Average corpuscular hemoglobin concentration: 33.33 g/dl and Average corpuscular hemoglobin: 73.9 pg. This is the first study of hematological values for this particular species in Colombia.

Reproduction in the red-legged pademelon, Thylogale stigmatica Gould (Marsupialia : Macropodidae), and age estimation and development of pouch young

1994 ◽  
Vol 21 (5) ◽  
pp. 553 ◽  
Author(s):  
PM Johnson ◽  
K Vernes
Keyword(s):  
Age Estimation ◽  
Post Partum ◽  
General Pattern ◽  
Age Determination ◽  
Gestation Period ◽  
Growth Equation ◽  
In Captivity ◽  
In The Wild ◽  
The Mean

The reproduction of Thylogale stigmatica in captivity was studied and a predictive growth equation for age determination of the pouch young was developed. The general pattern of reproduction involved an oestrous cycle of 29-32 days, a gestation period of 28-30 days and a mean pouch life of 184 days. A post-partum oestrus and mating generally followed birth. Births were observed in all months in captivity, and from October to June in the wild. Mean age of weaning of young was 66 days following permanent pouch emergence, and the mean ages at maturity for females and males was 341 and 466 days, respectively.

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