The group Incertae sedis within the Characidae family currently includes 88 genera, previously included in the subfamily Tetragonopterinae. Among them is the genus Astyanax comprising a group of species with similar morphology and widely distributed in the Neotropics. Thus, the present study aimed to analyze the karyotype diversity in Astyanax species from different watersheds by conventional G...

An experiment on the polyculture of carps with high valued small indigenous fish species (SIS) pabda (Ompok pabda) and gulsha (Mystus cavasius) was carried out in six months culture period to evaluate the production performance of carp with small indigenous fish pabda (Ompok pabda) and gulsha (Mystus cavasius) in the on-farm condition. Three stocking densities of pabda and gulsha were tested, k...

ABSTRACT One of the constraints in pirarucu, Arapaima gigas farming is reproduction captivity, due to inconsistent number spawning events per reproductive cycle, thus, unreliable availability juvenile fish. This a first-hand report on predation pirarucu larvae by opportunistic fish species breeding pond. Fish samples were collected for stomach content analysis from pirarucu-breeding pond with r...

Extended maternal care is considered a prerequisite for the evolution of permanent family grouping and eusociality in invertebrates. In spiders, the essential evolutionary transitions to permanent sociality along this ‘subsocial route’ include the extension of care beyond hatching, the persistence of offspring groups to maturation and the elimination of premating dispersal. Subsocial Australian...

Honeybee royal jelly is reported to have body-enlarging effects in holometabolous insects such as the honeybee, fly and silkmoth, but its effect in non-holometabolous insect species has not yet been examined. The present study confirmed the body-enlarging effect in silkmoths fed an artificial diet instead of mulberry leaves used in the previous literature. Administration of honeybee royal jelly...

Aside being a key nocturnal Agricultural pest, the two spotted cricket is an important source of protein for humans and livestock. While control is largely by synthetic pesticides, collection is majorly through hand picking and pouring of water into their burrows. In this study, we determined their phototactic response to LED and incandescent bulb light of different colours. An experiment was s...

The synthetic hormone, 17-α-methyltestosterone (MT), is used in fish hatcheries to induce male monosex. Androgenic effects on various fish species have been reported; however, few studies have assessed possible genotoxic effects, although there are concerns about such effects in target and non-target species. We evaluated genotoxic and gonadal effects of MT in adult tilapia (Oreochromis nilotic...

Understanding speciation hinges on understanding how reproductive barriers arise between incompletely isolated populations. Despite their crucial role in speciation, prezygotic barriers are relatively poorly understood and hard to predict. We use two closely related cricket species, Gryllus bimaculatus and G. campestris, to experimentally investigate premating barriers during three sequential m...

In insects, there are two different modes of segmentation. In the higher dipteran insects (like Drosophila), their segmentation takes place almost simultaneously in the syncytial blastoderm. By contrast, in the orthopteran insects (like Schistocerca (grasshopper)), the anterior segments form almost simultaneously in the cellular blastoderm and then the remaining posterior part elongates to form...