Distribution and position maintenance behaviour of the estuarine mysid Neomysis integer

Abstract

The distribution of Neomysis integer (Crustacea: Mysidacea) in a tidally mixed estuary was found to be concentrated in mid-estuary with animals extending, primarily in summer, further up and down estuary. Within this range there were distinct intra-specific differences in distribution, with males occurring more commonly down-estuary and ovigerous females and juveniles up-estuary. Examination of tidal abundances in mid-channel showed males to be more abundant on the ebb tide, corresponding with their more downstream distribution, and all other individuals to be present mainly on flood tides, which would maintain the species within the estuary. Endogenous circa-tidal swimming activity in this species was found to be phased after the time of expected high tide, which would suggest ebb tide swimming in the estuary. More detailed examination of the distribution of Neomysis across the width of the estuary showed greatest concentrations of animals in slow-flowing water at the edge of the channel during the ebb tide. The endogenous swimming rhythm may therefore act to prevent stranding of animals intertidally during the ebb tide, while maintenance of position along the estuary appears to be by flood tide swimming under exogenous control.

Seasonality, reproductive biology and ecology of Mesopodopsis zeylanica (Crustacea: Mysida) from a tropical estuary (Cochin backwater) in India

“…This may be due to the effect of tidal current in these areas. Many workers have described the influence of tidal current on the distribution of zooplankton and mysids (Heubach 1969, Wooldridge & Erasmus 1980, Wooldridge & Bailey 1982, Hill 1991, Hough & Naylor 1991, 1992, Moffat & Jones 1993.…”

Open Water Processes of the San Francisco Estuary: From Physical Forcing to Biological Responses

“…Mysids or opossum shrimp are small (<20 mm) shrimp-like crustaceans that are common in estuaries worldwide. Mysids are abundant in the Low-Salinity Zones of many if not most riverdominated temperate estuaries (Jones et al 1990;Hough and Naylor 1992). Amphipods are also small crustaceans that are usually associated with benthic habitats but can be abundant in the plankton.…”

Increased Zooplankton Behavioral Stress in Response to Short-Term Exposure to Hydrocarbon Contamination

“…Mysids have been frequently used in laboratory toxicity tests [75][76] but, despite a large literature on their swimming behavior [77][78], there are only a few published data on the effects of toxicant exposure on mysid swimming. For instance, the swimming ability and orientation of the Neomysis integer were disrupted after 7 day exposure to heavy metals [79] and pesticides [80].…”