Microsmatic fish are represented by numerous freshwater and marine species in which the well developed visual system provides most of the behavioural responses in comparison with the less developed chemosensory system. Visually guided diurnal or twilight predators as well as visually guided bentivorous and planktivorous species form this group of fish. The chemosensory system of microsmatic fish is active in providing their reproductive behaviour, social behaviour, spatial migration, partially anti-predator behaviour and is weak or indifferent in providing feeding responses.

Here, we consider esociform fish.

Esocidae

5 species: Esox americanus, E. lucius, E. masquinongy, E. niger, E. reicherti

Fresh waters of boreal Eurasia and Northern America

Northern pike, E. lucius, and other representatives of Esox genus, including Amur pike, E. reicherti, and some North American species, are apexpredators with the well developed vision and lateral line system.

According to data received by Devitsyna & Malyukina (1977) in the electrophysiological experiments, the olfactory system of pike, E. lucius, responds only to conspecific sexual pheromones (gonad extracts), but does not respond to conspecific odors, pure water and feeding substances like fish blood or tissue extracts. In feeding behaviour, musky, E. masquinongy, use vision and seismosensory system (New et al., 2001).

Pike larvae decrease the frequency of their attacks on zooplankters and show other anti-predator responses to chemical cues of Eurasian perch, Perca fluviatilis (Lehtiniemi, 2005; Lehtiniemi et al., 2005). It is also shown that pike are attracted by alarm pheromone of fathead minnow, Pimephales promelas (Mathis et al., 1995; Chivers et al., 1996; indirect data by Wisenden & Thiel, 2001).

Dalliidae

3 species: Dallia admirabilis, D. delicatissima, D. pectoralis

Fresh waters of Bering Sea basin

Blackfish primarily feed on crustacens (ostracods, cladocerans, copepods) and insect larvae (ephemeropterans, hemipterans, dipterans, odonates), with the occasional cannibalism and consumption of juvenile pike, E. lucius (Chlupach 1975).

However, leading sensory systems in feeding and reproductive behaviours of blackfish are unknown.

In winter with the oxygen lack, blackfish concentrate in the vicinity of holes in the ice, being easy to capture with the simple funnel-shaped traps made from strips of tamarack or spruce (Andersen et al., 2004). In spring and fall, blackfish are also easily caught while migrating to and from their summer habitats by placing the traps in narrow channels, it is appear these traps are not baited.

Umbridae

4 species: Novumbra hubbsi and Umbra krameri, U. limi, U. pygmaea

Fresh waters of Europe and Northern America

According to rare observations, feeding behaviour of mudminnows is rather provided by vision. For example, European mudminnow, U. krameri, eat in an aquarium only living and moving invertebrates such as cladocerans, copepods, Chaoborus larvae, chironomid larvae, culicid larvae, mayflay larvae, Acellus aquaticus and tubificid worms (Kováč, 1997). Cannibalism and hunting on juvenile fish in the nature are occasionally observed. However, Glasgow & Hallock (2009) report that Olimpic mudminnows, Novumbra hubbsi, are caught by the minnow traps baited with the chironomid larvae baits (15 g of chironomid larvae per one funnel-shaped trap). So, the problem of sensory providing of feeding behaviour in mudminnows is currently unclear.

On the other hand, chemical cues may play an important role in social and anti-predator behaviours of mudminnows. Indeed, central mudminnows, U. limi, demonstrate anti-predator behaviour in response to conspecific chemical alarm cues (Wisenden et al., 2007). Yet, mudminnows display comlex reproductive behaviour, from territory guarding to parental care (Hagen et al., 1972; Bohlen, 1995; Kováč, 199 ... Read more »