Belgian Journal of Zoology最新文献

{"title":"Reproductive capacity of male bank voles (Myodes glareolus Schreber, 1780) – age-dependent changes in functional activity of epididymal sperm","authors":"M. Kruczek, J. Styrna, J. Kapusta","doi":"10.26496/bjz.2013.129","DOIUrl":"https://doi.org/10.26496/bjz.2013.129","url":null,"abstract":"The influence of age on male bank voles’ reproductive tract development, epididymal sperm quantity and functional activity was investigated. Experiments were carried out on male bank voles aged 1.5 to 15 months (n=10 each in 8 age groups). The developmental stage of the reproductive tract was assessed by the weight of testes, seminal vesicles and coagulation glands. In each age group the number of epididymal sperm and their functional activity were examined. Epididymal sperm functional activity was assessed by motility, viability, maturity, head morphology and integrity of the sperm tail membrane. Ageing males were heavier than pre-pubertal and mature ones. Male age also affected the testes, seminal vesicles and coagulation gland development. The heaviest accessory sex glands were noted in 3-month-old males and the lightest in pre-pubertal (1.5-month-old) and older (12- and 15-month-old) males. Sperm counts were significantly higher in 3-, 4- and 5-month-old males than in pre-pubertal and old males. Generally, adult males aged 3- and 4- months, produced sperm of better functional activity. In conclusion, the best male reproductive capacity is found in bank voles of 3 to 4 months of age.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rediscovery of Branchipus schaefferi (Branchiopoda: Anostraca) in Belgium - notes on habitat requirements and conservation management","authors":"B. Vanschoenwinkel, L. Brendonck, Tom Pinceel, Pascal Dupriez, A. Waterkeyn","doi":"10.26496/bjz.2013.119","DOIUrl":"https://doi.org/10.26496/bjz.2013.119","url":null,"abstract":"Fairy shrimps (Crustacea, Anostraca) are specialized inhabitants of inland water bodies that \u0000periodically dry or freeze over. Here we report the first observation since 1997 of a member of this basal crustacean order in Belgium and the first sighting of the species Branchipus schaefferi Fischer, 1834 since 1930. Nineteen populations were found in a restricted area located 55 km SE of Brussels in the Province of Hainaut. Based on a field survey, we discuss the habitat characteristics of these populations. We discuss also the distribution and habitat requirements of the species based on literature and formulate a number of guidelines for the conservation of this species as well as other large branchiopods in densely settled areas with intensive agriculture such as Belgium. Finally, we formulate a number of likely explanations for the lack of recent observations of these organisms in Western Europe and in Belgium.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autecology of the extant ostracod fauna of Lake Ohrid and adjacent waters - a key to paleoenvironmental reconstruction","authors":"Julia Lorenschat, A. Schwalb","doi":"10.26496/bjz.2013.123","DOIUrl":"https://doi.org/10.26496/bjz.2013.123","url":null,"abstract":"Understanding the ecology of bioindicators such as ostracods is essential in order to reconstruct past environmental and climate change from analysis of fossil assemblages preserved in lake sediment cores. Knowledge of the ecology of ancient Lake Ohrid’s ostracod fauna is very limited and open to debate. In advance of the Ohrid ICDP-Drilling project, which has potential to generate high-resolution long-term paleoenvironmental data of global importance in paleoclimate research, we sampled Lake Ohrid and a wide range of habitat types in its surroundings to assess 1) the composition of ostracod assemblages in lakes, springs, streams, and short-lived seasonal water bodies, 2) the geographical distribution of ostracods, and 3) the ecological characteristics of individual ostracod species. In total, 40 species were collected alive, and seven species were preserved as valves and empty carapaces. Of the 40 ostracod species, twelve were endemic to Lake Ohrid. The most common genus in the lake was Candona, represented by 13 living species, followed by Paralimnocythere, represented by five living species. The most frequent species was Cypria obliqua. Species with distinct distributions included Heterocypris incongruens, Candonopsis kingsleii, and Cypria lacustris. The most common species in shallow, flooded areas was H. incongruens, and the most prominent species in ditches was C. kingsleii. C. lacustris was widely distributed in channels, springs, lakes, and rivers. Statistical analyses were performed on a “Lake Ohrid” dataset, comprising the subset of samples from Lake Ohrid alone, and an “entire” dataset comprising all samples collected. The unweighted pair group mean average (UPGMA) clustering was mainly controlled by species-specific depth preferences. Canonical Correspondence Analysis (CCA) with forward selection identified water depth, water temperature, and pH as variables that best explained the ostracod distribution in Lake Ohrid. The lack of significance of conductivity and dissolved oxygen in CCA of Ohrid data highlight the uniformity across the lake of the well-mixed waters. In the entire area, CCA revealed that ostracod distribution was best explained by water depth, salinity, conductivity, pH, and dissolved oxygen. Salinity was probably selected by CCA due to the presence of Eucypris virens and Bradleystrandesia reticulata in short-lived seasonal water bodies. Water depth is an important, although indirect, influence on ostracod species distribution, which is probably associated with other factors such as sediment texture and food supply. Some species appeared to be indicators for multiple environmental variables, such as lake level and water temperature.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hurdles in investigating UVB damage in the putative ancient asexual Darwinula stevensoni (Ostracoda, Crustacea)","authors":"L. V. D. Broecke, J. Vanfleteren, K. Martens, I. Schön","doi":"10.26496/bjz.2013.131","DOIUrl":"https://doi.org/10.26496/bjz.2013.131","url":null,"abstract":"Ostracoda or mussel-shrimps are small, bivalved Crustacea. Because of their excellent fossil record and their broad variety of reproductive modes, ostracods are of great interest as a model group in ecological and evolutionary research. Here, we investigated damage and repair from one of the most important biological mutagens, namely UVB radiation, in the putative ancient asexual ostracod Darwinula stevensoni from Belgium. We applied three different methods: the Polymerase Inhibition (PI) assay, Enzyme-Linked Immuno Sorbent Assay (ELISA) and dot blot. All three techniques were unsuccessful in quantifying UVB damage in D. stevensoni. Previous experiments have revealed that the valves of D. stevensoni provide an average UVB protection of approximate 60%. Thus, UVB damage could be too little to make quantitative experiments work. Additionally, variation between individual ostracods due to season and age most likely contributed further to the failure of the three used experimental approaches to quantify damage. In a second experiment, we investigated the influence of temperature on survival of D. stevensoni during UVB exposure. The estimated relative lethal UVB dose at 4°C was with 50 kJ/m2, significantly lower than at room temperature, with 130 kJ/m2. This could either indicate lack of adaptation to low temperatures and/or the presence of metabolic processes active at room temperature protecting against UVB damage in D. stevensoni. The latter possibility could also explain why the estimated relative lethal UVB dose of D. stevensoni is similar to that of other non-marine ostracods where valves provide around 80% protection, despite the valves of D. stevensoni providing less protection. If such metabolic processes can repair UVB damage quickly, this may provide an alternative explanation why we could not quantify UVB damage in D. stevensoni.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal Changes in the thermal tolerances of Odontophrynus occidentalis (Berg, 1896) (Anura: Cycloramphidae)","authors":"E. Sanabria, L. Quiroga, A. Martino","doi":"10.26496/bjz.2013.121","DOIUrl":"https://doi.org/10.26496/bjz.2013.121","url":null,"abstract":"We studied the thermal tolerances of Odontophrynus occidentalis during the dry and wet seasons of the Monte Desert in San Juan Province, Argentina. This toad had differences in CTmax between dry and wet seasons, with CTmax values being greater in the wet season (Austral summer). Operative temperature, body temperature, and environmental maximal temperature were related to CTmax suggesting seasonal acclimatization in O. occidentalis. Additionally, the CTmax recorded for O. occidentalis was 36.1ºC, and the maximum ambient temperature measured during the toads’ activity time was 37ºC. The CTmin of O. occidentalis was 4.1ºC while the minimum environmental temperature recorded was 7.2 ºC. The wide tolerance range observed and the relationship between tolerance limits and the environmental extremes indicate that seasonal acclimatization is an effective mechanism by which toads can raise their thermal tolerance. This is a highly relevant adaptation allowing them to survive in the challenging conditions of the Monte Desert.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140245210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective use of forest habitat by Biłgoraj horses","authors":"Daniel Klich, Magdalena Grudzień","doi":"10.26496/bjz.2013.132","DOIUrl":"https://doi.org/10.26496/bjz.2013.132","url":null,"abstract":"Primitive horses are quite often kept in nature reserves with access to the forest, which they sometimes penetrate to use the vegetation. Horses, as grazers, use specific foraging and anti-predator strategies that differ from typical browsers. The aim of the study was to assess the factors influencing the pattern of forest use by Bilgoraj horses. We hypothesized that the essential factors influencing their pattern of foraging are: browse abundance, distance to pasture, and openness of the habitat. Data were collected at the Biłgoraj Horse-Breeding Centre near Janów Lubelski, Poland. The horses browsed significantly more on woody vegetation in parts of the forest more exposed to sunlight and more abundant in browse material (especially containing preferred species). Distance to the main pasture had a significant effect upon browsing intensity only when an interaction with the abundance of preferred browse was considered.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic analysis of swimming ontogeny in seabass (Dicentrarchus labrax)","authors":"D. Olivier, N. Vandewalle, Q. Mauguit, É. Parmentier","doi":"10.26496/bjz.2013.125","DOIUrl":"https://doi.org/10.26496/bjz.2013.125","url":null,"abstract":"Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus labrax, a marine fish from cold, temperate waters. The data were compared with results from previous studies on two subtropical freshwater catfish species (Clarias gariepinus and Corydoras aeneus). The three species have different modes of locomotion each during their adult stage (anguilliform, subacarangiform and carangiform). The swimming of Dicentrarchus labrax was recorded with a high-speed video camera (500 fps) from 0 to 288 hours and from 960 to 2496 hours post-hatching. Three indices, i.e. coefficient of determination (r²), coefficient of variation (CV), and Strouhal number (St), were used to investigate the establishment and efficiency of swimming. Important differences in the timing of swimming establishment were observed between the seabass and the two catfish species. The two catfish species display a sine-shaped swimming mode immediately or soon after hatching, and the efficiency of movement substantially improves during the first days of life. For seabass, however, establishment of swimming is slower during the same developmental period. These differences may be related to a faster developmental rate in the catfishes that allows them to swim rapidly in an intermediate regime flow and to develop the required morphology to establish efficient movements earlier.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific morphological and genetic variation in South African populations of a polystomatid flatworm parasite","authors":"A. L. Schoeman, N. Kmentová, M. Vanhove, L. D. du Preez","doi":"10.26496/bjz.2024.118","DOIUrl":"https://doi.org/10.26496/bjz.2024.118","url":null,"abstract":"The African Clawed Frog Xenopus laevis, a global invader, exhibits a marked phylogeographic divergence among native populations in southern Africa, which seems to enhance its invasive potential. The polystomatid flatworm, Protopolystoma xenopodis, is the frog’s most frequently co-introduced metazoan parasite. In an integrative approach, we utilised morphometrics and molecular markers to assess variation in P. xenopodis in its native range. We measured twelve key morphological characters from 23 flatworms and compared these statistically between flatworms collected from the northern- and southernmost distribution in South Africa. Phylogenetic analyses were based on three concatenated markers, namely 28S and 12S rDNA and COX1, from six flatworms. The combination of five morphological characters, which involve egg size, gut morphology and size of the attachment hooks, differentiated northern and southern populations of P. xenopodis. The multilocus phylogenetic analyses showed a cluster of northern P. xenopodis and two southern lineages with more basal positioning. These findings demonstrate a relatively high level of intraspecific variation in P. xenopodis in its native range. The presented intraspecific variation of P. xenopodis could be potentially informative to trace geographic origin in its non-native range.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139833731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific morphological and genetic variation in South African populations of a polystomatid flatworm parasite","authors":"A. L. Schoeman, N. Kmentová, M. Vanhove, L. D. du Preez","doi":"10.26496/bjz.2024.118","DOIUrl":"https://doi.org/10.26496/bjz.2024.118","url":null,"abstract":"The African Clawed Frog Xenopus laevis, a global invader, exhibits a marked phylogeographic divergence among native populations in southern Africa, which seems to enhance its invasive potential. The polystomatid flatworm, Protopolystoma xenopodis, is the frog’s most frequently co-introduced metazoan parasite. In an integrative approach, we utilised morphometrics and molecular markers to assess variation in P. xenopodis in its native range. We measured twelve key morphological characters from 23 flatworms and compared these statistically between flatworms collected from the northern- and southernmost distribution in South Africa. Phylogenetic analyses were based on three concatenated markers, namely 28S and 12S rDNA and COX1, from six flatworms. The combination of five morphological characters, which involve egg size, gut morphology and size of the attachment hooks, differentiated northern and southern populations of P. xenopodis. The multilocus phylogenetic analyses showed a cluster of northern P. xenopodis and two southern lineages with more basal positioning. These findings demonstrate a relatively high level of intraspecific variation in P. xenopodis in its native range. The presented intraspecific variation of P. xenopodis could be potentially informative to trace geographic origin in its non-native range.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139774093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sexual dimorphism and allometry in the head and body size of two viperid snakes (genus Vipera)","authors":"B. Borczyk, Przemysław Puszkiewicz, Stanisław Bury","doi":"10.26496/bjz.2024.117","DOIUrl":"https://doi.org/10.26496/bjz.2024.117","url":null,"abstract":"Sexual dimorphism in the size and shape of the body and head is the result of manifold selective pressures acting on organisms. In snakes, sexual size dimorphism is common and has been well-studied. However, intersexual differences in relative head size and shape have attracted far less attention. Similarly, the allometric properties of head shape and size in snakes are poorly known. Here, we analyse sexual dimorphism in two viperid species: European adder Vipera berus (Linnaeus, 1758) and Steppe viper Vipera renardi (Christoph, 1861). We measured body length, tail length and several head characteristics: head length, head width, head height, pileus length, interorbital distance and internarial distance. Our findings were that males and females of both species did not differ in body length (SVL), but that males tended to have significantly longer tails; there were also significant differences in head characteristics – males tended to have higher heads, and larger internarial and interorbital distances. The head dimensions displayed negative allometry when compared against SVL but when scaled against head length, dimensions like head height and head width exhibited positive allometry. We argue that these differences may be related to sexual selection and that the wider heads may also serve as antipredatory signal.","PeriodicalId":8750,"journal":{"name":"Belgian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}