scholarly journals Reproductive aspects of the poorly known and critically endangered freshwater snail Heleobia atacamensis (Gastropoda: Truncatelloidea)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11550
Author(s):  
Gonzalo A. Collado ◽  
Elizabeth Chihuailaf ◽  
Natalia Muñoz-Herrera ◽  
Manuel Contreras ◽  
Fernando Novoa ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Austral Summer ◽  
Freshwater Snail ◽  
Iucn Red List ◽  
Critically Endangered ◽  
Size Frequency Distribution ◽  
Starting Point ◽  
Management Plans

Knowing the reproductive biology of threatened species is essential for conservation and to establish proper management plans. Heleobia atacamensis, a freshwater snail only known from two locations in the Atacama Saltpan, northern Chile, is currently classified as Data Deficient on the IUCN Red List and Critically Endangered by the Ministerio del Medio Ambiente of Chile. Based on size-frequency distribution, multivariate analysis of shell measurements, and microdissections, we studied the reproductive strategy, recruitment period, sex ratio and sexual dimorphism in this species. Heleobia atacamensis is an oviparous species, with direct development (non-planktotrophic). Females lay capsules of a single egg from which a juvenile resembling a miniature adult hatches after intracapsular metamorphosis is completed. The development type was confirmed by the observation of a paucispiral protoconch (= protoconch I) using scanning electron microscopy. Recruitment was observed across the four seasons of the year, with an increment at the end of austral summer. Results also showed that sex ratio was 1:1, whereas sexual dimorphism was not detected using univariate and multivariate analysis of the shell. The reproductive data provided in this study are a starting point for future management plans.

Annual cycle of growth and population structure of the estuarine crab Hemigrapsus crenulatus (Brachyura: Varunidae) off central Chile

2021 ◽  
pp. 1-15
Author(s):  
Ramiro A. Riquelme-Bugueño ◽  
Tomás Luppi ◽  
Gonzalo S. Saldías ◽  
Marcelo E. Lagos ◽  
Mauricio A. Urbina ◽  
...  
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Size Distribution ◽  
Annual Cycle ◽  
Linear Models ◽  
Environmental Variability ◽  
Growth Parameters ◽  
Austral Summer ◽  
Size Frequency Distribution ◽  
Central Chile

Abstract Estuaries and saltmarshes play a fundamental role in the life cycle of many crab species. Diverse studies show that temperature and salinity modulate abundance, size frequency distribution (SFD), sex ratio and growth in crustaceans. These population parameters are usually challenging to estimate due to the high environmental variability of estuaries. Monthly samples of the estuarine crab Hemigrapsus crenulatus were taken from October 2003 to October 2004 (except July 2004) in the Tubul estuary, central Chile. We quantified temporal changes in abundance, size distribution, sex ratio and monthly growth through the annual cycle. A total of 1025 individuals were collected. Sizes ranged from 7.72–33.51 mm carapace length (CL) with a growth rate ranging between 2.13–30.5% mm CL mo−1. Size and growth rates were greater in spring-summer, suggesting a faster growth of younger crabs correlated with increasing sea temperatures in the austral summer. Overall, sex ratio was 1.75:1 in favour of males. Modal analysis identified at least seven cohorts cohabiting throughout the annual cycle. Growth parameters for males and females were the following, respectively: L∞ = 33.6 and 29.6, k = 0.69 and 0.91, t0 = –0.39 and −0.28. Changes in size distribution suggested a recruitment period during autumn and winter seasons when there are lower salinities and temperature fluctuations stresses. Generalized linear models indicated that sea temperature, salinity and chlorophyll were the environmental variables that better predicted the annual patterns in the population structure.

scholarly journals Aspek Biologi Pari Kekeh (Rhynchobatus sp. (Rhinidae:Chondrichthyes)) Studi Kasus di PPN Brondong, Lamongan

2021 ◽  
Vol 10 (1) ◽  
pp. 78-88
Author(s):  
Lara Azidha ◽  
Irwani Irwani ◽  
Munasik Munasik
Keyword(s):  
Sex Ratio ◽  
Iucn Red List ◽  
Red List ◽  
Critically Endangered ◽  
High Price ◽  
Chi Square ◽  
Gonad Maturity ◽  
A Value ◽  
Good Taste ◽  
Biological Aspects

Pari kekeh (Rhynchobatus sp.) adalah organisme laut yang tergolong dalam Subkelas Elasmobranchii dan dikelompokkan ke dalam Kelas Chondrichthyes. Pari kekeh sering ditangkap dikarenakan dagingnya memiliki rasa yang enak, Selain itu, sirip Pari kekeh memiliki harga yang mahal  di China dan Global. Pari kekeh telah masuk kedalam daftar IUCN red list kategori critically endangered akibat eksploitasi berlebihan. Hal ini apabila terus terjadi maka ketersedian sumber daya Pari kekeh di habitatnya terancam punah. Oleh karena itu, perlu adanya pengaturan agar tidak terjadi eksploitasi berlebihan yang berdampak pada populasi pari kekeh, salah satunya dengan melakukan analisis aspek biologi. Tujuan dari penelitian ini untuk mengetahui hubungan panjang berat, nisbah kelamin, tingkat kematangan gonad, ukuran pertama kali matang gonad dan fekunditas Pari kekeh yang didaratkan di PPN Brondong. Sampel yang digunakan yaitu pari kekeh sebanyak 160 ekor. Penelitian ini menggunakan metode deskriptif dengan mengukur data panjang total dan standar, bobot, pengamatan gonad. Pola pertumbuhan Pari kekeh yaitu allometrik negatif (b = 2,52). Nisbah kelamin = 0,625 (Chi Square) dengan X tabel = 3,975, maka jumlah Pari jantan dan betina seimbang. Kematangan gonad Pari Rhynchobatus sp. sebesar 53%. Ukuran pertama kali matang gonad Pari kekeh jantan memiliki panjang total 48,97-49,16 cm dan Pari kekeh betina memiliki panjang total 95,29-98,60 cm. Nilai fekunditas Pari kekeh berkisar antara 5-16 butir pada kisaran panjang total tubuh 86-114 cm.  Kekeh Stingrays (Rhynchobatus sp.) are marine organisms that classified to the Elasmobranchii subclass and grouped into the Chondrichthyes Class. Kekeh Stingrays is often caught because has a good taste. In addition, Kekeh Stingrays fins have a high price in the Stingray and Shark fin trade in China and Global. Kekeh Stingrays has entered into the IUCN red list in the critically endangered category due to overexploitation. If excessive exploitation continues, the availability of Stingray resources in their habitat will be threatened. Therefore, there is a need for control to avoid overexploitation that affects the population of Kekeh Stingrays, one of which is by analyzing the biological aspects. The purpose of this study was to determine the length and weight correlation, sex ratio, gonad maturity level, size of the first gonad maturity, and fecundity of Kekeh Stingray which was landed in PPN Brondong. The samples used were 160 Kekeh Stingrays. This research uses descriptive method by measuring the total and standard length, weight, also gonad observations. The results obtained are the length and weight correlation of Stingray Kekeh which is negative allometric with a value of b = 2.52. The sex ratio based on Chi Square (x2) = 0,625 with X table = 3,975, that means the number of male and female Stingray is balanced. The value of  TKG II and TKG III of Rhinchobatus sp.that is, 53% is dominated by matured Rays. The first size of gonad maturity for rays was in a range 48,97-49,16 cm, while for female rays was in a range 95,29-98,60 cm. The Value of Kekeh Stingrays’s fecundity was around 5-16 eggs with the total length range is 86-114 cm.

scholarly journals Range extension of the poorly known and Critically Endangered freshwater snail, Heleobia transitoria (Biese, 1947) (Gastropoda, Cochliopidae), in the Atacama Desert, northern Chile

Check List ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 785-792
Author(s):  
Gonzalo A. Collado ◽  
Carmen Gloria Fuentealba
Keyword(s):  
New Record ◽  
Conservation Status ◽  
Atacama Desert ◽  
Freshwater Snail ◽  
Morphological Characters ◽  
Iucn Red List ◽  
Red List ◽  
Critically Endangered ◽  
Northern Chile ◽  
Current Conservation

The range distribution of Heleobia transitoria (Biese, 1947) is confined only to its type locality, Quebrada Cachina, a ravine located on the Atacama Desert coast in the Antofagasta Region, northern Chile. The species is classified as “En Peligro Crítico” according to Ministry of the Environment of Chile, a category equivalent to Critically Endangered (CR) of the IUCN Red List of Threatened Species, in part for its restricted distribution. This paper reports the occurrence of H. transitoria in the Atacama Region, Chile, after the study of morphological characters using light and scanning electron microscopy. This new record highlights considering the limited distribution and current conservation status of the species.

Genetic Diversity and Structure of the Nile Soft-Shelled Turtle (Trionyx triunguis) Along the Mediterranean coast of Turkey

2020 ◽  
Vol 27 (6) ◽  
pp. 307-315
Author(s):  
Özgür Güçlü ◽  
Bülent Bozdoğan
Keyword(s):  
Microsatellite Loci ◽  
Geographic Distance ◽  
Iucn Red List ◽  
Genetic Variations ◽  
Mediterranean Coast ◽  
Critically Endangered ◽  
Mediterranean Populations ◽  
Genetic Diversity And Structure ◽  
Polymorphic Microsatellite ◽  
The Mediterranean

The Nile soft-shelled turtle (Trionyx triunguis) is distributed between Dalyan and Samandağ throughout the Mediterranean coast in Turkey. The Mediterranean subpopulation of the Nile soft-shelled turtle is listed as critically endangered in the IUCN Red List Categories. This investigation aimed to determinate levels of genetic variations and patterns of genetic structures among Mediterranean populations in Turkey by using T. triunguis-specific microsatellite primers. A total of 13 polymorphic microsatellite loci were studied among samples of 121 individuals collected from five populations in Turkey. Of 13 polymorphic microsatellite loci used, 3 new were identified in this study. The genetic differentiation among the 5 studied populations of T. triunguis was significant (p 0.001). The analysis of molecular variance (AMOVA) indicated that genetic variations occurred mainly within populations (89.7%) rather than among populations (10.3%). Structure analysis showed presence of two main groups among the Mediterranean T. triunguis populations. However genetic variations among populations were not correlated with geographic distance between the locations. Analysis of data showed that one of the populations (Dalyan) had undergone a bottleneck effect. Migration analysis indicates that T. triunguis migrates between five Mediterranean populations in Turkey. We concluded that based on our results the status of ‘critically endangered’ of T. triunguis should be maintained. Long term population genetic survey studies should be undertaken and changes in habitats of T. triunguis populations, as well as their population size and structure should be monitored for each population to be able to establish a clear strategy for protection of T. triunguis.

scholarly journals Advances on the Implementation of Circular Economy Techniques in Rural Areas in Colombia under a Sustainable Development Framework

2021 ◽  
Vol 13 (7) ◽  
pp. 3816
Author(s):  
Javier Rodrigo-Ilarri ◽  
Camilo-A. Vargas-Terranova ◽  
María-Elena Rodrigo-Clavero ◽  
Paula-A. Bustos-Castro
Keyword(s):  
Sustainable Development ◽  
Waste Management ◽  
Circular Economy ◽  
Rural Areas ◽  
Development Framework ◽  
Starting Point ◽  
Management Plans ◽  
Good Starting Point ◽  
Depressed Regions ◽  
First Time

For the first time in the scientific literature, this research shows an analysis of the implementation of circular economy techniques under sustainable development framework in six municipalities with a depressed economy in Colombia. The analysis is based on solid waste data production at a local scale, the valuation of the waste for subsequent recycling, and the identification and quantification of the variables associated with the treatment and final disposal of waste, in accordance with the Colombian regulatory framework. Waste generation data are obtained considering three different scenarios, in which a comparison between the simulated values and those established in the management plans are compared. Important differences have been identified between the waste management programs of each municipality, specifically regarding the components of waste collection, transportation and disposal, participation of environmental reclaimers, and potential use of materials. These differences are fundamentally associated with the different administrative processes considered for each individual municipality. This research is a good starting point for the development of waste management models based on circular economy techniques, through the subsequent implementation of an office tool in depressed regions such as those studied.

Multivariate analysis of sexual dimorphism in two types of dermatoglyphic traits in five endogamous populations of West Bengal, India

HOMO ◽  
2003 ◽  
Vol 53 (3) ◽  
pp. 263-278 ◽  
Author(s):  
B. Karmakar ◽  
K. Yakovenko ◽  
E. Kobyliansky
Keyword(s):  
Multivariate Analysis ◽  
Sexual Dimorphism ◽  
West Bengal ◽  
Endogamous Populations ◽  
Dermatoglyphic Traits

Do secondary sexual dimorphism and female intolerance to drought influence the sex ratio and extinction risk of Taxus baccata?

Plant Ecology ◽  
2008 ◽  
Vol 200 (2) ◽  
pp. 229-240 ◽  
Author(s):  
Grzegorz Iszkuło ◽  
Anna K. Jasińska ◽  
Marian J. Giertych ◽  
Adam Boratyński
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Extinction Risk ◽  
Taxus Baccata ◽  
Secondary Sexual Dimorphism ◽  
Secondary Sexual

Updating the knowledge of the flower flies (Diptera: Syrphidae) from Chile: Illustrated catalog, extinction risk and biological notes

Zootaxa ◽  
2021 ◽  
Vol 4959 (1) ◽  
pp. 1-178
Author(s):  
RODRIGO M. BARAHONA-SEGOVIA ◽  
PAMELA RIERA ◽  
LAURA PAÑINAO-MONSÁLVEZ ◽  
VICENTE VALDÉS GUZMÁN ◽  
PATRICIA HENRÍQUEZ-PISKULICH
Keyword(s):  
Extinction Risk ◽  
Critical Role ◽  
Floral Biology ◽  
Iucn Red List ◽  
Decomposition Of Organic Matter ◽  
Management Plans ◽  
Flower Flies ◽  
Iucn Red List Criteria ◽  
Definition Of ◽  
First Time

Syrphidae, more commonly known as flower flies, are considered one of the most important Diptera families worldwide because of their critical role in pollination, biological control and decomposition of organic matter. The study of these flies in Chile has stagnated due to a lack of local experts as well as the absence of an updated catalog of species. This study is an attempt to remedy the latter of these issues by providing an illustrated and updated catalog to the Syrphidae of Chile. Species are presented under currently accepted names, with synonyms and previous combinations listed and original references. Type localities, world and Chilean distribution by geopolitical Chilean regions, taxonomic and biological notes, a complete record of bibliographic references and extinction risk under IUCN Red List criteria are provided. This catalog recognizes 132 species of Syrphidae, belonging to four subfamilies (Eristalinae, Microdontinae, Pipizinae and Syrphinae), 13 tribes and 47 genera. A total of 46 species (34.84 %) is restricted to the geopolitical territory of Chile. Eight species are considered exotic, one is considered incertae sedis and three are based on doubtful records. Seventeen species of 10 different genera (Copestylum Macquart, 1846; Dolichogyna Macquart, 1842; Eosalpingogaster Hull, 1949b; Eupeodes Osten Sacken, 1877; Meromacrus Rondani, 1848; Palpada Macquart, 1834; Paragus Latreille, 1804; Sphiximorpha Rondani, 1850; Sterphus Philippi, 1865 and Toxomerus Macquart, 1855) are reported from Chile for the first time. A total of 44 species (33.33 %) reported from Chile are directly threatened by human activities such as agriculture, forestry, mining and/or urbanization and indirectly by climate change. The gaps found in the geographic distribution of Chilean flower fly species and what it means for its use by disciplines such as ecology, floral biology and agronomy, are discussed. In addition, the use of this illustrated catalog for biological conservation, the potential definition of priority areas and ecosystem management plans based on this group of Diptera are also discussed. 

Novelties in Begonia (Begoniaceae) from the campos rupestres of Serra do Padre Ângelo, Minas Gerais, Brazil: a new species and a new record

Phytotaxa ◽  
2021 ◽  
Vol 510 (1) ◽  
Author(s):  
LUDOVIC JEAN CHARLES KOLLMANN ◽  
PAULO MINATEL GONELLA
Keyword(s):  
New Species ◽  
High Elevation ◽  
Iucn Red List ◽  
Minas Gerais ◽  
Small Population ◽  
Critically Endangered ◽  
Campos Rupestres ◽  
Rock Outcrops ◽  
Critically Endangered Species ◽  
Minas Gerais State

Begonia piranga (Begoniaceae) is a new narrowly endemic species from the campos rupestres of Serra do Padre Ângelo, a quartzitic massif in Conselheiro Pena, eastern Minas Gerais state, Brazil. Description, diagnosis, taxonomic comments, detailed illustrations, field photographs, and a provisional IUCN Red List Assessment are provided. The new species is considered Critically Endangered due to its restricted occurrence in high elevation rock outcrops, small population size, and decline in the quality of the habitat. Begonia vasconcelosiana, another Critically Endangered species, is also newly reported here for Serra do Padre Ângelo. These discoveries add to the increasing list of novelties from Serra do Padre Ângelo, reinforcing the urge for conservation actions to protect the endemic flora of this Serra and other areas of campos rupestres in eastern Minas Gerais state.

scholarly journals Population biology of the crab Armases angustipes (Crustacea, Decapoda, Sesarmidae) at Brazilian tropical coast

2014 ◽  
Vol 104 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Marina de Sá Leitão C. de Araújo ◽  
Deusinete de O. Tenório ◽  
Daniela da S. Castiglioni
Keyword(s):  
Population Structure ◽  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Population Biology ◽  
Carapace Width ◽  
Reproductive Activity ◽  
Coastal Regions ◽  
Phytoplankton Productivity ◽  
Number Of Individuals ◽  
Tropical Coast

The semi terrestrial crabs are important elements of the fauna of coastal regions. The aim of this study was to analyze the population structure of Armases angustipes (Dana, 1852) at estuaries of the Ariquindá River, considered a non impacted area, and Mamucabas River, considered a few impacted area, on the south coast of state of Pernambuco, Brazil. The species occurred in all months of the year. The number of individuals per month varied, being higher in the months of transition between the seasons. This is probably due to significant seasonal variations of air and burrow temperature and burrow salinity. There was no sexual dimorphism in size of A. angustipes in the mangrove of Ariquindá River, but males were larger than females in the mangrove of Mamucabas River. In both estuaries, the sex ratio did not differ from Mendelian proportion, but showed a deviation for females. The analysis of temporal variation in sex ratio showed significant differences in some months of the year. These variations are due to cyclical events that act distinctly on each sex. In both estuaries, size classes of carapace width were equally represented by both sexes. The ovigerous females of A. angustipes occurred only in some months of the year, especially in summer, in both estuaries. Probably the high phytoplankton productivity observed in summer favors the reproductive activity, since these algae serve as food for the larvae. Specimens of the population of Rio Ariquindá are largest and wider than those of Mamucabas River. This fact, associated with the low abundance of crabs and the lower frequency of ovigerous females observed in Mamucabas River, is an indication that this population may be influenced by the environmental impacts that this estuary has received.

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