Establishment of a Genetically Confirmed Breeding Colony of Mastomys natalensis from Wild-Caught Founders from West Africa

Mastomys natalensis are a ubiquitous and often dominant rodent across sub-Saharan Africa. Importantly, they are a natural reservoir for microbial pathogens including Lassa virus (LASV), the etiological agent of Lassa fever in humans. Lassa-infected rodents have been documented across West Africa and coincide with regions where annual outbreaks occur. Zoonotic transmission to humans most often occurs directly from infected rodents. Little is known about LASV infection kinetics and transmissibility in M.natalensis, primarily due to available animals. Here, we describe the establishment of a laboratory breeding colony of genetically confirmed M.natalensis from wild-captured rodents. This colony will provide a convenient source of animals to study LASV and other emerging pathogens that utilize M. natalensis in their enzootic lifecycles.

Биологоэкологические особенности развития и размножения фасолевой зерновки (Acanthoscelides obtectus Say.) В условиях лаборатории

When mass laboratory breeding of bean seeds (Acanthoscelides obtectus Say.), it should be taken into account that the hatching of larvae from eggs and their settlement of beans should take place in the dark. Subsequent phases of development and maintenance of beetles are carried out in natural light at an optimal temperature of 24-30 degrees with the use of bean seeds of the Belskaya 16 variety.

Microbiota potentialized larvicidal action of imidazolium salts against Aedes aegypti (Diptera: Culicidae)

Mosquitoes are important vectors of pathogens due to their blood feeding behavior. Aedes aegypti (Diptera: Culicidae) transmits arboviruses, such as dengue, Zika, and Chikungunya. This species carries several bacteria that may be beneficial for its biological and physiological development. Therefore, studying the response of its microbiota to chemical products could result in vector control. Recently, imidazolium salts (IS) were identified as effective Ae. aegypti larvicides. Considering the importance of the mosquito microbiota, this study addressed the influence of IS on the bacteria of Ae. aegypti larvae. After exposition of larvae to different IS concentrations, the cultured microbiota was identified through culturomics and mass spectrometry, and the non-cultivated microbiota was characterized by molecular markers. In addition, the influence of the IS on axenic larvae was studied for comparison. There was an alteration in both cultivable species and in their diversity, including modifications in bacterial communities. The axenic larvae were less susceptible to the IS, which was increased after exposing these larvae to bacteria of laboratory breeding water. This highlights the importance of understanding the role of the larval microbiota of Ae. aegypti in the development of imidazolium salt-based larvicides. Such effect of IS towards microbiota of Ae. aegypti larvae, through their antimicrobial action, increases their larvicidal potential.

Description of the third instar larva of a hypogean ground beetle, Trechus alicantinus (Coleoptera: Carabidae: Trechinae)

Description and illustrations are provided for the third instar larva of Trechus alicantinus Español, 1971 obtained from a laboratory breeding. This paper aims to contribute to increase the general knowledge about microendemic hypogean species of the east of the Iberian Peninsula. Besides, it expands the existing knowledge about the preimaginal stages of the genus Trechus and the whole tribe Trechini (Coleoptera, Carabidae). Larvae can give additional information about the life style of the species. Larvae can also express, even more than the imagos, some apomorphic characters, traditionally considered a result of adaptation to the hypogean habitat, such as the regression of ocular structures. The characteristic lack of stemmata is discussed. This type of event, which also appears in other Trechini larvae, is probably more related to phylogenetic lineages than with an adaptive response to hypogean environment.

Kijing Taiwan Flour Subtitution in 3-5 cm Tilapia Fish Feed Frmulation (Substusi Tepung Kijing Taiwan Dalam Formulasi Pakan Ikan Nila Ukuran 3-5 cm)

The research was conducted in the Nutrition and Fish Feed Technology Laboratory. Breeding container used is 15 units of Aquarium and each container stocked with 10 fishes at size 3-5 cm. The objectives of this research is: to determine the effect of feeding with different composition of Kijing Taiwan flour to the Relative growth of tilapia fish and to determine which Kijing Taiwan feed composition that has the best feed efficiency value for tilapia. The research design used was a Completely Randomized Design (CRD) using five (5) different treatments and three (3) repetitions. Where Treatment A (0% without flour Kijing Taiwan), treatment B (10% flour Kijing Taiwan), treatment C (20% flour Kijing Taiwan), treatment D (30% flour Kijing Taiwan) and treatment E (40% flour Kijing Taiwan ). The frequency of feeding was 3 times a day with a weight of 5% from the fish total weight. An observation of growth was done once a week. The analysis results of the five treatments applied, showed that the relative growth value during the research for Treatment E contribute (387.62%), followed by treatment D (268.57%), treatment C (202.86%), treatment B (182, 86%) and treatment A (131.43%). Meanwhile for the Feed Efficiency Value in treatment E contribute (48.73%) followed by treatment B (40.14%), treatment C (37.03%), treatment D (36.70%) and treatment A (28.91%). It can be concluded that the feed with additional 40% of Kijing Taiwan flour provide better relative growth and better feed efficiency value than any other feeds. Keywords: Substitution, flour Kijing Taiwan, relative growth, feed efficiency and tilapia

Metaplasia in swim bladder epithelium of the endangered annual fish Austrolebias nigrofasciatus (Cyprinodontiformes: Rivulidae) results in inadequate swimming and delayed growth

ABSTRACT Laboratory breeding of annual fish is often impaired when fish fail to inflate the swim bladder after hatching. These fish, which are known as belly-sliders, cannot swim in the water column, moving mainly on the bottom of water. Therefore, we wanted to understand the factors underlying failed inflation of swim bladder in the annual fish Austrolebias nigrofasciatus and determine the implications of this condition on the growth of juveniles. To identify how the initial filling of the gaseous vesicle is compromised, and to determine the implications of this condition on juvenile growth, we analysed the histology of the swim bladder of both normal swimming fish and belly-sliders during their initial growth phase (first month of life). In addition to slower growth rate compared with fish swimming normally, we found that belly-sliders have metaplasia characterized by epithelium peeling of the swim bladder and the presence of haemorrhage. Based on our findings, it can be concluded that metaplasia of the swim bladder is recurrent in annual fish bred in the laboratory, which explains the large number of unviable larvae. However, its causes remain unknown.

Habitat establishment, captive breeding and conservation translocation to save threatened populations of the Vulnerable European mudminnow Umbra krameri

In Europe 37% of freshwater fish are threatened. However, conservation activity is less widespread for fish compared to other vertebrate groups. The Vulnerable European mudminnow Umbra krameri is a marshland fish endemic to the Carpathian Basin. Its range and population have declined significantly since the 1990s. The main threats to the species are habitat loss and the invasive Chinese sleeper Perccottus glenii. During 2008–2012 a species conservation programme was established to rescue broodstocks from threatened populations, breed them under controlled conditions, translocate both rescued fish and their laboratory-reared offspring to surrogate habitats, and finally reintroduce offspring to their original habitats. Broodstocks from three threatened habitats were bred in the laboratory and produced offspring appropriate for stocking. Six artificial ponds were created in the pilot study area according to the environmental needs of the species, four of which proved to be suitable surrogate habitats in which translocated fish survived and reproduced successfully. Populations in the original habitats were supplemented with fish from laboratory breeding and from the natural recruitment of surrogate habitats, with special care of the corresponding broodstocks. Future challenges include improving our knowledge about the ecological processes in which the European mudminnow participates, identifying the most threatened populations, habitats suitable for restoration and potential areas for creation of surrogate habitats, and enhancing induced propagation methodology.