scholarly journals Sexual dimorphism and morphometric analysis of Filopaludina martensi martensi (Gastropoda: Viviparidae)

2021 ◽  
Vol 31 (2) ◽  
pp. 87-92
Author(s):  
Weerachon Sawangproh ◽  
Chetsada Phaenark ◽  
Supatra Chunchob ◽  
Paiphan Paejaroen

Sexual dimorphism is the condition where individuals of different sex in the same species exhibit different characteristics beyond the differences in their sexual organs. In this study, individuals of a viviparid species Filopaludina martensi from the Kwai Yai River in Kanchanaburi Province (Thailand) were examined for eight shell and operculum characteristics. Sexual differences were observed in size of shell and operculum, with females being larger than males. The results indicated that morphometric analyses are useful to detect subtle differences between sexes in this species.

Author(s):  
Karen J. Escalante-Flórez DDS ◽  
Daniel G. Suárez-Ponce DDS, MSc, PhD ◽  
Ymelda W. Velezmoro-Montes DDS, MSc

Objective: Determine sexual dimorphism precision via palatal vault morphometric analysis in craniums sourced from the Laboratorio de Investigación Forense del Equipo Forense Especializado (EFE) de Ayacucho del Ministerio Público - Perú. Materials and Methods: Cross-sectional design consisting of a sample of 43 skulls with pre-established biological gender, (24 males and 19 females). Sexual dimorphism was established by means of the method proposed by Meera Jacob and co., based on palatal width and length measurements, after which the palatal index was calculated, establishing the method’s precision and accuracy. The inferential analysis was made with a level of significance of 5% through the T student test, Shapiro Wilk and Pearson’s coefficient. Results: Palatal width had a mean of 3.43 (+0.31cm) for males and 3.62 (+0.25) for females and in palatal length a mean of 5.07 (+0.44) cm. for males and 4.79 (+0.41) cm. for females is established; on palatal index, 100% of the male skulls correspond to hard narrow palate and on females 73.7% to narrow, 21% to intermediate and 5.3% to wide. Furthermore, it was determined that there were statistically significant differences between width and length of palatal vault for both genders, and a discriminating analysis formula was proposed. Conclusion: Morphometric analyses of palatal vaults establish an 83.72% precision on the estimation of sexual dimorphism.


Zootaxa ◽  
2019 ◽  
Vol 4563 (1) ◽  
pp. 83
Author(s):  
ALEJANDRA P. PÉREZ ◽  
CORINA A. COVIAGA ◽  
LORENA Y. RAMOS ◽  
JULIO LANCELOTTI ◽  
MARTA S. ALPERIN ◽  
...  

In this study we redescribe an ostracod species belonging to the subfamily Cypridopsinae Kaufmann, 1900, sampled in seven localities of northern and southern Patagonia, Argentina. A new taxonomical combination is proposed, Cypridopsis silvestrii comb. nov., based on detailed description of females and the first descriptions of males. Cypridopsis silvestrii occurred on a wide geographical distribution range, from 40º to 48º S latitude, as well as broad environmental tolerance ranges. We evaluated morphological variations in two populations of C. silvestrii from northern (El Toro lake) and southern (El Sello lake) Patagonia, with contrasting limnological conditions. El Toro is a small shallow lake with high salinity waters and El Sello is a large deep lake with lower salinity. Based on morphometric analysis, our results showed intraspecific variation in valve shape and size between populations. Sexual dimorphism in El Toro population was identified through morphometric analyses. Additionally, comparison of valve outlines in living and subfossil individuals from El Toro lake allowed specimens previously described as juveniles of Eucypris fontana (Graf, 1931) to be identified as adults of C. silvestrii comb. nov. The present contribution increases knowledge of the taxonomic identity, the ecological requirements and the geographical distribution of C. silvestrii, and shows that morphometric analyses are a feasible and useful tool for exploring intraspecific shape differences and assisting in taxonomic identification. Furthermore, the results presented herein provide tools for C. silvestrii identification in paleolimnological studies, and emphasize the usefulness of studying living representatives for clarification of the taxonomic status of species widely distributed in Quaternary sediments. 


2007 ◽  
Vol 21 (3) ◽  
pp. 216-221 ◽  
Author(s):  
Marilene Issa Fernandes ◽  
Eduardo José Gaio ◽  
Rui Vicente Oppermann ◽  
Pantelis Varvaki Rados ◽  
Cassiano Kuchenbecker Rosing

The purpose of this study was to compare histologic and morphometric procedures of bone height measurement. Microscopic measurements are the most frequent methods in periodontal studies with animals, but have limited capacity to identify bone levels associated with both healthy tissues and periodontal disease. Ligatures were placed in the maxillary left second molars of 10 male 60-day-old Wistar rats for 30 days. Left and right maxillary sides of 5 rats were processed for histologic analysis (H), sectioned buccolingually, and stained with HE. The maxillae of the other 5 rats were defleshed and used for morphometric analysis (M). Histometric measurements from the cementoenamel junction to the bone crest were performed. Standardized photographs were used for morphometric analysis. The t test was used for dependent or independent samples (alpha = 0.05%). Distances from cementoenamel junction to bone crest were 0.95 ± 0.25 and 1.07 ± 0.30 mm for H and M, respectively. Buccal measurements were 0.92 ± 0.16 and 1.08 ± 0.35 mm for H and M. The values obtained using H and M for areas without ligatures were 0.44 ± 0.15 and 0.47 ± 0.11 mm for lingual measurements and 0.23 ± 0.08 and 0.41 ± 0.10 mm for buccal measurements. No significant differences were found between the two methods in the detection of bone height associated with the placement of ligatures in rats.


2019 ◽  
Vol 04 (12) ◽  
pp. 762-765
Author(s):  
Dr. Gaurav Katheriya ◽  
Dr Nida Khan ◽  
Dr. Vikram Khanna ◽  
Dr. Ranjitkumar Patil ◽  
Dr. Anurag Tripathi ◽  
...  

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Abdelnasser Ibrahim ◽  
Aspalilah Alias ◽  
Mohamed Swarhib Shafie ◽  
Faridah Mohd Nor

The present systematic review explores the most sexually dimorphic parameters by using geometric morphometric analysis of human skull. An extended search was conducted in Google Scholars and PubMed (published between 2005 and 2017). The main inclusion criteria were research articles published in English, and studies that used geometric morphometric analysis for classification of human skull. The literature search identified 54 potential relevant articles whereby, five had met the inclusion criteria. Most studies reported positive contribution of geometric morphometric as an alternative and accurate tool for classification of unknown human crania. Geometric morphometric method resulted in a high classification accuracy of sexual dimorphism among different populations. Further studies are required to approach the best method used for varied types of postcranial bones equipped with a more advanced meta-analysis of the results.


2018 ◽  
Vol 96 (8) ◽  
pp. 801-817 ◽  
Author(s):  
C.A. Coviaga ◽  
A.P. Pérez ◽  
L.Y. Ramos ◽  
P. Alvear ◽  
G.C. Cusminsky

Two species of ostracods new to Patagonia, Argentina, are described. One of them, Riocypris whatleyi sp. nov., is described for the first time, and the second, Riocypris sarsi (Daday, 1902) comb. nov., is reallocated from genus Eucypris to genus Riocypris. Inter- and intra-specific variations in shape, size, and sexual dimorphism were evaluated based on geometric morphometric analysis. Moreover, morphological and morphometric comparative analyses were applied to re-examine living and quaternary specimens recovered from previous studies. Based on these results, a generic reassignment for the Patagonian Eucypris fontana (Jurine, 1820) into the genus Riocypris is proposed. Contributing to the knowledge on the systematic and autecology of this enigmatic species, widely distributed in Patagonia and frequently used in paleolimnological reconstructions, generates science-based evidence for their use as indicator species. Additionally, our results emphasize the usefulness of studying the living representatives (i.e., with valves and appendages) for elucidating the taxonomic status of the individual specimens, especially those present in paleontological records and used as bioproxies in paleolimnological studies.


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 484
Author(s):  
Łukasz Sobczyk ◽  
Michał Filipiak ◽  
Marcin Czarnoleski

Nutritional limitations may shape populations and communities of organisms. This phenomenon is often studied by treating populations and communities as pools of homogenous individuals with average nutritional optima and experiencing average constraints and trade-offs that influence their fitness in a standardized way. However, populations and communities consist of individuals belonging to different sexes, each with specific nutritional demands and limitations. Taking this into account, we used the ecological stoichiometry framework to study sexual differences in the stoichiometric phenotypes, reflecting stoichiometric niches, of four spider taxa differing in the hunting mode. The species and sexes differed fundamentally in their elemental phenotypes, including elements beyond those most commonly studied (C, N and P). Both species and sexes were distinguished by the C:N ratio and concentrations of Cu, K and Zn. Species additionally differed in concentrations of Na, Mg and Mn. Phosphorous was not involved in this differentiation. Sexual dimorphism in spiders’ elemental phenotypes, related to differences in their stoichiometric niches, suggests different nutritional optima and differences in nutritional limitation experienced by different sexes and species. This may influence the structure and functioning of spider populations and communities.


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