Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sen...

It has recently been shown that a few fish species, including American shad (Alosa sapidissima; Clupeiformes), are able to detect sound up to 180 kHz, an ability not found in most other fishes. Initially, it was proposed that ultrasound detection in shad involves the auditory bullae, swim bladder extensions found in all members of the Clupeiformes. However, while all clupeiformes have bullae, n...

In the present investigation flocculation of dissolved Cu, Zn, Pb, Ni and Mn in a series of mixtures with salinities ranging from 1.5 to 9.5% during mixing of Talar river water with the Caspian Sea water was studied. The flocculation trend of Zn (87.22%) >Mn (45.31%) >Pb (39.09%) >Cu (36.58%)>Ni (12.70%) indicates that Cu, Zn, Pb and Mn have non-conservative behavior and Ni has relatively conse...

Marine microorganisms have unique physiological properties and novel metabolites such as biosurfactant to live in extreme habitats (e.g. oil polluted environment). The aim of this study was to characterize some biosurfactant-producing bacteria collected from sediment and seawater samples from the Caspian Sea. These bacteria were isolated using enrichment method in ONR7a medium with crude oil as...

Most fish cannot hear frequencies above 3 kHz, but a few species belonging to the subfamily Alosinae (family Clupeidae) can detect intense ultrasound. The response of adult specimens of the European allis shad (Alosa alosa) to sinusoidal ultrasonic pulses at 70 and 120 kHz is tested. The fish showed an intensity-graded response to the ultrasonic pulses with a response threshold between 161 and ...

1.1 Caspian Sea The complex history of the Caspian Sea formation has lead to a variety of different habitats. Like Australia, the Caspian Sea became isolated thousands of years ago (Plate 1). This isolation led to the speciation of many rare animals in particular the sturgeon. The Caspian Sea is the biggest enclosed body of water on Earth, having an even larger area than that of the American Gr...

Many species of odontocete cetaceans (toothed whales) use high-frequency clicks (60-170 kHz) to identify objects in their environment, including potential prey. Behavioral studies have shown that American shad, Alosa sapidissima, can detect ultrasonic signals similar to those of odontocetes that are potentially their predators. American shad also show strong escape behavior in response to ultra...

More than 10,000 Caspian seals (Phoca caspica) were reported dead in the Caspian Sea during spring and summer 2000. We performed necropsies and extensive laboratory analyses on 18 seals, as well as examination of the pattern of strandings and variation in weather in recent years, to identify the cause of mortality and potential contributory factors. The monthly stranding rate in 2000 was up to ...

The Global climate reorganisation in the late Pliocene linked to enhancement of Atlantic Ocean Thermohaline Circulation (AOTC), instigated a transition glacial-interglacial cyclicity Quaternary. Enhancement AOTC amplified atmospheric precipitation over Eurasian interior strengthening Northern Hemisphere Glaciation. Increased rainfall on vast Russian Plain drained into endorheic Caspian Sea, whi...