Spawning Behavior of Chum Salmon (Oncorhynchus keta) and Rainbow Trout (Salmo gairdneri)

Abstract

Detailed accounts of the spawning behavior of chum salmon (Oncorhynchus keta) and rainbow trout (Salmo gairdneri) in laboratory flumes are provided. The behavioral activities, quivering, probing, and crossing over increase in frequency as a function of time prior to spawning whereas digging remains constant or decreases slightly. Maps of digging locations and movie films suggest nest shape and current pattern are monitored by the female, allowing her to intensify her digging activity near the center of the nest. Probing appears to be a signal to the male indicating approach of oviposition and also provides information to the female regarding the shape and suitability of the nest site. The probing act is also used in the synchronization of the male and female spawning acts. Changes in velocity do not appear to markedly affect nest construction either in terms of number of digs to oviposition or in size of nest constructed. It is inferred that velocity and gravel size are important insofar as they influence the construction of a suitable nest depression. Nest sites would appear to be selected on the basis of acceleration of flow rather than velocity per se though high limits must obviously exist.

Vibrational communication during spawning behavior in the himé salmon (landlocked red salmon,Oncorhynchus nerka)

“…In accordance with this supposition, synchronous spawning is achieved in the salmon through a stimulusreaction chain of behaviors between the sexes (Jones and King 1949;Tautz and Groot 1975;Satou and Ueda 1982;Satou 1987). This suggests that signals as to the timing of gamete release are exchanged during spawning behavior.…”

Mature males of Arctic charr,Salvelinus alpinus, release F-type prostaglandins to attract conspecific mature females and stimulate their spawning behaviour

“…Reproductive behaviour has been described for many salmonids, including Arctic charr (Fabricius & Gustafson 1954, Sigurj6nsdottir & Gunnarsson 1989, Dolly Varden (Needham & Vaughan 1952), Miyabe charr (Maekawa 1983), lake charr (Foster 1985), eastern brook charr (Smith 1941), steelhead trout (Needham & Taft 1934), rainbow trout (Tautz & Groot 1975, Honda 1980, Atlantic salmon (Belding 1934, Jarvi 1990, and cutthroat trout (Smith 1941), as well as for many of the Pacific salmons (Hanson & Smith 1967, Tautz & Groot 1975, Honda 1982, Kwain 1982, Keenleyside & Dupuis 1988 . The same general pattern can be identified for all salmonids .…”

Quantifying the Behavioral Response of Spawning Chum Salmon to Elevated Discharges from Bonneville Dam, Columbia River : Annual Report 2005-2006.

“…We determined the number of digs (in 15-min intervals) made by the female fish to construct her nest and then calculated means for each fish during periods of base and elevated tailwaters. We made a distinction between digs made to construct a nest and digs made to cover eggs after a spawning event following the observations of Tautz and Groot (1975) and Tiffan et al (2005). Covering digs were excluded from analyses since they comprised such a small portion of the total digging time but had the potential to inflate mean values because of their greater numbers per unit time (e.g., ~70/15 min).…”

“…Our 2-m criterion for defining the area a fish would most likely occupy over it's redd may have been conservative as increasing this distance to 5 m included most fish locations. Female chum salmon move off their redds when chasing intruding fish (Schroder 1981;Tautz and Groot 1975;Tiffan et al 2005) or when one or more intruding males enter the redd to fight with the courting male. We have observed this behavior on numerous occasions at Ives Island, during which times the female fish will leave for extended periods of time.…”