Oceanologia (Dec 2002)
Reproductive cycle and the related spatial and temporal distribution of the ninespine stickleback (<i>Pungitius pungitius L.</i>) in Puck Bay
Abstract
The cycle of gonad development and related changes in thelength structure and spatial-temporal distribution ofninespine sticklebacks (Pungitius pungitius L.) in Puck Baywere studied. Observations were carried out in the shallowshore zones, as well as in the deeper epipelagic zone ofthe Bay. Ninespine sticklebacks reproduce in the brackishenvironment of Puck Bay, breeding in its warmer, inshore zones.Reproduction takes place in the spring and summer months, fromApril to July. One female spawns several clutches of eggs duringone breeding season. The average length of ninespine sticklebacksin Puck Bay was about 40 mm, and the sex ratio in the population wasclose to 1:1. However, both length structure and sex ratio weresubject to local and periodic variations, resulting from possiblebreeding-related territorial divisions. Higher gonadosomaticindices in females in early spring represented the transition offish to the advanced vitelligenous phase. The lowest GSI of males duringthe breeding season indicated the termination of spermatogenesis. Thecompletion of spawning in August started a new process of gonad restorationto prepare the fish for the next breeding season.
