In the dusky pipefish Syngnathus floridae, like other species in the family Syngnathidae, 'pregnant' males provide all post-zygotic care. Male pregnancy has interesting implications for sexual selection theory and the evolution of mating systems. Here, we employ microsatellite markers to describe the genetic mating system of S. floridae, compare the outcome with a previous report of genetic pol...

Visual responses of adult male and female Colorado potato beetles CPB, Leptinotarsa decemlineata (Say) (Coleoptera, Chrysomelidae) to 10 × 20 cm coloured paper-boards, beetle-sized coloured beads or dead CPB, and to combinations of these in laboratory experiments in an arena of 52 cm diameter were investigated. In addition, visual discriminatory abilities of males exposed to female-specific sub...

Most theoretical models of unsteady aquatic movement in organisms assume that including steady-state drag force and added mass approximates the hydrodynamic force exerted on an organism's body. However, animals often perform explosively quick movements where high accelerations are realized in a few milliseconds and are followed closely by rapid decelerations. For such highly unsteady movements,...

Grasshoppers are divided into two major subgroups: the short-horned grasshoppers (Figure 1) and the long-horned grasshoppers, Mormon crickets and katydids (Figure 2). Short-horned grasshoppers are responsible for most of the reported crop losses. As a result, individuals of this subgroup are popularly referred to as “grasshoppers.” Figure 1. A mature two-striped female grasshopper (Melanoplus b...

Seahorses, pipefish and their syngnathiform relatives are considered unique amongst fishes in using elastic recoil of post-cranial tendons to pivot the head extremely quickly towards small crustacean prey. It is known that pipefish activate the epaxial muscles for a considerable time before striking, at which rotations of the head and the hyoid are temporarily prevented to allow energy storage ...

In monogamous animals, males are usually the predominant competitors for mates. However, a strictly monogamous pipefish Corythoichthys haematopterus exceptionally exhibits a reversed sex role. To understand why its sex role is reversed, we measured the adult sex ratio and the potential reproductive rate (PRR), two principal factors influencing the operational sex ratio (OSR), in a natural popul...

In the year 2000, three hundred and eighty-one animals werw caught in 11 locations in the pedunculate oak forests extending across the wider region of the Sava River valley, an area known as an old natural focus of leptospires. Two hundred and twenty-seven animals were investigated for leptospiral carriership, 381 were tested for the existence of specific antibodies to leptospira. Through culti...

A stripe pattern is an aposematic or camouflage coloration often observed among various caterpillars. However, how this ecologically important pattern is formed is largely unknown. The silkworm dominant mutant Zebra (Ze) has a black stripe in the anterior margin of each dorsal segment. Here, fine linkage mapping of 3,135 larvae revealed a 63-kbp region responsible for the Ze locus, which contai...

Highly variable microsatellite loci were employed to study the mating system of the sexually dimorphic Gulf pipefish Syngnathus scovelli. In this species, like others in the family Syngnathidae, 'pregnant' males provide all parental care. Gulf pipefish were collected from one locale in the northern Gulf of Mexico, and internally carried broods of 40 pregnant males were analysed genetically. By ...

The genetic mating system is a key component of the sexual selection process, yet methods for the quantification of mating systems remain controversial. One approach involves metrics derived from Bateman's principles, which are based on variances in mating and reproductive success and the relationship between them. However, these measures are extremely difficult to measure for both sexes in ope...