Why are the prevalence and diversity of helminths in the endemic Pyrenean brook newt Calotriton asper (Amphibia, Salamandridae) so low?

2013 ◽  
Vol 89 (2) ◽  
pp. 175-181 ◽  
Author(s):  
M. Comas ◽  
A. Ribas

AbstractA cornerstone in parasitology is why some species or populations are more parasitized than others. Here we examine the influence of host characteristics and habitat on parasite prevalence. We studied the helminths parasitizing the Pyrenean brook newt Calotriton asper (n= 167), paying special attention to the relationship between parasites and ecological factors such as habitat, sex, ontogeny, body size and age of the host. We detected two species of parasites, Megalobatrachonema terdentatum (Nematoda: Kathlaniidae) and Brachycoelium salamandrae (Trematoda: Brachycoeliidae), with a prevalence of 5.99% and 1.2%, respectively. Marginally significant differences were found in the prevalence between sexes, with females being more parasitized than males. The present results show significant differences in the body length of paedomorphic and metamorphic individuals, the former being smaller. Nevertheless, no significant correlations between parasite prevalence and either newt body length, ontogenetic stage or age were found. In comparison with other Salamandridae living in ponds, prevalence and diversity values were low. This may be due to a long hibernation period, the species' lotic habitat and its reophilous lifestyle, which probably do not allow for a high parasite load.

2018 ◽  
Vol 11 (2) ◽  
pp. 183-189
Author(s):  
Junardi Junardi

AbstrakCacing Nipah Pendek Namalycastis abiuma memiliki tubuh yang elastis dan mudah putus sehingga diperlukan pendekatan morfometri tubuh lain untuk menentukan panjang tubuh sesungguhnya. Tujuan penelitian ini untuk menentukan panjang tubuh total cacing nipah pendek dengan menggunakan bobot tubuh, jumlah total segmen berseta, panjang tiga segmen anterior pertama (L3) dan lebar segmen berseta atau setiger ke-10 (S-10). Spesimen yang digunakan dipilih hanya individu yang lengkap dan utuh. Pengukuran dilakukan dibawah mikroskop dengan lensa okular yang dilengkapi dengan mikrometer. Data dianalisis dengan analisis korelasi. Cacing yang digunakan sebanyak 258 individu yang terdiri atas 190 immature, 54 submature dan 14 mature dengan ukuran panjang tubuh rata-rata berturut-turut 108,62±34,80 mm, 172,27±42,78 mm dan 123,14±57,40 mm. Cacing betina ditemukan memiliki ukuran tubuh lebih besar dari jantan. Panjang tubuh N. abiuma dapat diduga dengan bobot tubuh, panjang L3 dan lebar S-10 dengan nilai koefisien korelasi (r) berturut-turut 0,82, 0,73 dan 0,78. Pendekatan morfometri dapat digunakan untuk menentukan ukuran tubuh N. abiuma.Abstract The short nypa palm worm Namalycastis abiuma has an elastic and fragile body. Therefore, an alternative approach of morphometrical techniques is needed to determine the total body length. This research aimed to estimate the total body length of the short nypa palm worm based on body weight, the total number of segments, the length of the first three anterior segment (L3) and the tenth setiger width (S10). Body measurement was done using stereomicroscope fitted with the micrometer. Correlation analysis was done to describe the relationship between the length of L3 and the width of S10. A total of 258 complete and whole specimens consisted of 190 immature, 54 submature, and 14 mature individuals. The average body length of immature individuals was 108.62±34.80 mm, 172.27±42.78 mm for sub mature individuals, and 123.14±57.40 mm for mature individuals. Based on sexual dimorphism, the female body size is larger than male. The body length of N. abiuma can be estimated by body weight, the length of L3, and the  width of S10, with  correlation coefficient (r) of 0.82, 0.73 and 0.78, respectively. Morphometry approach can be used to determine the body size of N. abiuma. 


Author(s):  
C. C. E. Hopkins

Analyses of the relationship between the size and the number of eggs per female in various decapods, isopods, cumaceans and mysids were made by Jensen (1958) based upon personal research and information from available literature. Regression analyses indicated that the number of eggs per female is related to the cube of the body length.


2006 ◽  
Vol 66 (1a) ◽  
pp. 85-93 ◽  
Author(s):  
M. I. Hamann

From December 1995 to November 2000, the seasonal maturation of Glypthelmins vitellinophilum Dobbin, 1958, in its definitive host, the frog Lysapsus limellus Cope, 1862, was studied in a subtropical permanent pond in northeastern Argentina. The objectives of this study were: 1) to determine the infrapopulation dynamics of the parasite, analyzing the seasonal maturation cycle throughout the years; and 2) to examine the relationship between the intensity of trematode infection in different developmental stages (recruitment, growth and maturation) and the host's body length. Of a total of 1,400 frogs examined over 60 months (5 years), 38% were found to be infected with G. vitellinophilum, and the intensity of infection was 1-15 trematodes per frog. Specimens of G. vitellinophilum were present in L. limellus throughout the years, but did not show a pronounced seasonal maturation cycle. Possible reasons for these findings are discussed with reference to climatic fluctuations and biotic factors. The infective period of the parasite (stage I) occurred in summer, autumn and spring, coinciding with the time each frog cohort appeared. These infections were found principally in small body sizes (classes 1 and 2) of L. limellus. Juvenile and nongravid specimens of worms (stage II and III) were found in frogs of different body sizes throughout the period of investigation. Gravid specimens of the parasite (stage IV) were generally recorded in autumn, winter and spring, mainly in the bodies of larger frogs. The body length of Trematodes in stages I and IV was significantly and positively correlated with that of the frogs.


2019 ◽  
pp. 137-142
Author(s):  
Baaloudj Affef

Urothemis edwardsii is one of the most threatened dragonfly species in the Mediterranean. Recent investigations and conservation efforts have increased the local geographic distribution of the species in Northeast Algeria, where a new population (named El Graeate) has been discovered. In the absence of information about the biology and behavior of U. edwardsii in this new site, a study was conducted on the emergence ecology of the species taking into account the temporal pattern of emergence, sex ratio, body size and microhabitat selection. Emergence, which was quite asynchronous, lasted for 50 days, with 50% of the population emerging within the first half of the period. Sex ratio at emergence was slightly female biased despite the absence of sexual size dimorphism, suggesting that size is not the only driving force behind mortality bias during the larval stage. There was a slight seasonal increase in the body size of exuviae (exoskeletons) in both sexes. Microhabitat selection, assessed as the vertical stratification of exuviae at ecdysis, was positively correlated with the height of supporting plants, but the relationship reached a plateau suggesting that there are predetermined limits to the vertical distribution of exuviae. These data will be essential for the future species protection, restoration and management attempts in the region.


2019 ◽  
Vol 56 (2) ◽  
pp. 168-174 ◽  
Author(s):  
D. M. Amorim ◽  
R. W. Ávila

SummaryClimatic and ecological factors can influence the parasite load of a host. Variation in rainfall, body size, and sex of the hosts may be related to the abundance of parasites. This study investigated the helminth fauna associated with a population of Norops brasiliensis, together with the effect of host biology (sex, body size, and mass) and variation in rainfall regime on the abundance of helminths. Species of three groups of endoparasites were found (Nematoda, Cestoda, and Trematoda), with nematodes as the most representative taxa with eight species, prevalence of 63.2 %, mean intensity of 4.0 ± 0.58 (1 – 25), and mean abundance of 2.66 ± 0.44 (0 – 25). Nine helminth species are new host records for N. brasiliensis. The nematode Rhabdias sp. had the highest prevalence (53.3 %). There was no significant relationship between abundance of the trematode Mesocoelium monas and host sex or season, although the abundance of this parasite increased significantly with host body size and mass, while abundance of nematodes was related to season and host mass. This study increases the knowledge about the diversity of helminth fauna associated with N. brasiliensis, revealing infection levels of hosts from northeastern Brazil.


2018 ◽  
Vol 59 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Tamara Kanjuh ◽  
Danilo Mrdak

This study examined the relationship between the sagittal otolith morphometric variables (length, height and weight) and body growth of the European eel. Eels that were studied ranged in total length from 11.2 to 79.5 cm. The relationships between the sagittal otolith variables and fish somatic growth were described with a non-linear function. The resulting coefficients of determination \((r^2)\) ranged from 0.782 to 0.914. The variable most strongly related to fish size was found to be the sagittal otolith length (OL) with 91.4 % of the variability. The results of this study provide the first comprehensive data regarding the relationship between the sagittal otolith morphometric variables with the body length of Anguilla anguilla.


2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Furkan Herry ◽  
Mohammad Agus Nashri A. ◽  
Asril Asril

Penelitian ini dilaksanakan di 3 desa yang berbeda di Kecamatan Indrapuri, Kabupaten Aceh Besar. Penelitian berlangsung selama 30 hari yang dimulai dari tanggal 18 Februari - 19 Maret 2017. Penelitian ini bertujuan untuk mengevaluasi ukuran tubuh turunan sapi aceh pada umur sapih dengan sisitem pemeliharaan yang berbeda. Materi  yang digunakan dalam penelitian ini adalah anak sapi Aceh lepas sapih sebanyak 24 ekor. Metode penelitian ini menggunakan metode observasi yaitu dengan cara mengukur ternak turunan sapi Aceh lepas sapih tersebut. Penentuan desa dengan mempertimbangkan adanya sistem pemeliharaan sapi secara ekstensif dan intensif dan jumlah ternak sapi lepas sapih terpenuhi untuk pengambilan sampel. Parameter yang diamati dalam penelitian ini adalah lingkar dada, panjang badan, dan tinggi pundak. Hasil penelitian menunjukkan ukuran lingkar dada turunan sapi Aceh pada umur sapih yang di pelihara dengan system intensif menunjukkan ukuran yang lebih tinggi di bandingkan dengan ukuran lingkar dada yang dipelihara dengan system pemeliharaan ekstensif dan pada pengukuran panjang badan dan tinggi gumba turunan sapi Aceh yang di pelihara dengan system ekstensif menunjukkan ukuran yang lebih tinggi dibandingkan dengan ukuran  panjang badan dan tinggi gumba yang di pelihara dengan sistem intensifEvaluation of Body Size of Aceh Cow Beans with Different Maintenance System in Indrapuri Sub-district, Aceh BesarThis research was conducted in 3 different villages in Indrapuri Sub-district, Aceh Besar District. The study lasted for 30 days starting from February 18 to March 19, 2017. This study aims to evaluate the body size of aceh cows at the weaning age with different maintenance systems. The material used in this study is Aceh calf off weeds as much as 24 tail. This research method using the observation method that is by measuring the cattle of Aceh cattle derivatives off the weaning. Determination of the village taking into account the existence of an extensive and intensive cattle breeding system and the number of loose weaning cattle is fulfilled for sampling. Parameters observed in this study were chest circumference, body length, and shoulder height. The results showed that the size of the chest circumference of cows of Aceh cattle at the age of weaning with intensive care system showed a higher size in comparison with the size of the chest circumference maintained with extensive maintenance system and on the measurement of the length and height of the gumba derived from Aceh cows Extensive systems show a higher size compared to the size of the body length and height of the gumba maintained in an intensive system


2016 ◽  
Vol 25 (2) ◽  
pp. 225-230
Author(s):  
Cristina Fernandes do Amarante ◽  
Wagner de Souza Tassinari ◽  
Jose Luis Luque ◽  
Maria Julia Salim Pereira

Abstract The present study used regression models to evaluate the existence of factors that may influence the numerical parasite dominance with an epidemiological approximation. A database including 3,746 fish specimens and their respective parasites were used to evaluate the relationship between parasite dominance and biotic characteristics inherent to the studied hosts and the parasite taxa. Multivariate, classical, and mixed effects linear regression models were fitted. The calculations were performed using R software (95% CI). In the fitting of the classical multiple linear regression model, freshwater and planktivorous fish species and body length, as well as the species of the taxa Trematoda, Monogenea, and Hirudinea, were associated with parasite dominance. However, the fitting of the mixed effects model showed that the body length of the host and the species of the taxa Nematoda, Trematoda, Monogenea, Hirudinea, and Crustacea were significantly associated with parasite dominance. Studies that consider specific biological aspects of the hosts and parasites should expand the knowledge regarding factors that influence the numerical dominance of fish in Brazil. The use of a mixed model shows, once again, the importance of the appropriate use of a model correlated with the characteristics of the data to obtain consistent results.


1993 ◽  
Vol 14 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Barbara Plytycz ◽  
Janusz Bigaj

AbstractYellow-bellied toads were studied in their natural environment in a mountain locality in southeastern Poland. 608 specimens were captured, marked by yellow skin autografts placed in different parts of their dorsal surface according to body length, and released. Some of them were recaptured and measured from one to nine years later to estimate their growth and longevity. Yellow-bellied toads grew rapidly in early life; thereafter their growth was very limited. Body size was not an accurate age indicator of an individual of this species. The body length 51-55 mm was maximal in this locality. Yellow-bellied toads were long-lived in nature, some individuals surviving for much more than ten years, and perhaps even more than 20 years. The skeletochronological technique (counting the growth lines in phalangeal cross-sections of the clipped toes of some marked individuals) underestimated the actual age of these animals.


2008 ◽  
Vol 53 (1-4) ◽  
pp. 37-47
Author(s):  
Ewa Działa-Szczepańczyk

Gut Morphometrics in the Long-Tailed DuckClangula HyemalisWintering on the Polish Baltic CoastThe study included guts of 140 individuals of the long-tailed duckClangula hyemalisobtained in autumn and winter of 1993-2000 in the western part of the Polish Baltic Coast. The following morphometric characters were analysed: duodenum length (DL), combined jejunum and ileum length (JIL), small intestine length (SIL), combined terminal intestine and cloaca length (TCL), and combined length (CBL) and weight (CBW) of both caeca. In the analysis the birds' sex and age were taken into consideration, as well as their body size characterised by body weight, body length, and sternum length. Ontogenetic differences in the gut morphometric characters were more pronounced in males than in females, and immature drakes were characterised by higher average values of JIL and CBW, compared to adult males. Besides the CBL and CBW, sexual dimorphism was manifest in the body size and other gut measurements - those parameters achieved higher average values in males than in females. No such differences were recorded with respect to relative parameters: DL, SIL, and TCL expressed as the percentage of the birds' body length. In case of JIL, CBL, and CBW no relation with any of the body size parameters was found. No relevant relations between SIL and JIL, and the measurements of CBL and TCL were noticed.


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