Spawning population characteristics of pike Esox lucius L. in Lake Rubikiai (Lithuania)

Abstract

The aim of the study was to describe the peculiarities of pike spawning in mesotrophic Lake Rubikiai, to determine the spawning population structure and evaluate the influence of some environmental factors on year-class strength formation. The data were collected in April and May (1994–2011). A total of 1586 individuals were caught. The age of pike ranged from 1 to 12 years; 2–5-yearold males (96.0%) and 3–8-year-old females (89.1%) prevailed. The overall sex ratio of females to males was 1:4.1. One-year-old spawning males (26.5–28.5 cm) and two-year-old spawning females (31.5–35.5 cm) constituted 2.1% and 2.6%, respectively. Water temperature during the spawning period was relatively stable, between 4 and 6°C, during March and increased slightly towards 10°C in the middle of April. No correlation was observed between female length and spawning date. Year-class strength did not correlate with the last day of ice presence and the minimal water level at the end of spawning (WLmin), but statistically significantly negatively correlated with the maximum water level at the beginning of spawning (WLmax) and the difference between WLmax and WLmin. The mean annual survival rate for pike (aged ≥2) was 0.74 and the mean annual instantaneous mortality rate was 0.45.

Demographic variables and stock status of pike,Esox lucius, in the commercial fishery in the Anzali Wetland (SW Caspian Sea) near the southern limits of its distribution range

“…The age of pike can be determined by studying calcified structures such as cleithra, otoliths or scales (Faust et al, 2013;Sauvanet et al, 2013). Several studies have used scales for determining the age of pike (e.g., Mann, 1980;Lorenzoni et al, 2002;Žiliukiene _ and Žiliukas, 2012;Sauvanet et al, 2013). Scales were used here, because whole, undamaged pike could be sold after the scale sampling.…”

“…Scales were used here, because whole, undamaged pike could be sold after the scale sampling. Pike scales were taken from above the lateral line near the rear part of the dorsal fin and prepared for age determination (Roche and Bracken, 1999;Žiliukiene _ and Žiliukas, 2012). The scales were rapidly washed, cleaned and examined as dry mounts.…”

Reproductive characteristics of northern pike, Esox lucius (Actinopterygii: Esociformes: Esocidae), in the Anzali Wetland, southwest Caspian Sea

“…Although several studies have addressed the reproductive biology of this species (Bregazzi and Kennedy 1980, Treasurer 1990, Avian et al 1998, Lenhardt and Cakić 2002, Balık et al 2006, Nilsson 2006, Žiliukienė and Žiliukas 2012 ), the majority of them have been in regions of high latitudes (e.g., England, Scotland, Sweden, Germany, and Lithuania). Information on the reproductive biology of pike in lower latitudes is very limited, so that this study adds information on the variability and plasticity of its reproductive traits.…”

Modeling the effective spawning and nursery habitats of northern pike within a large spatiotemporally variable river landscape (St. Lawrence River, Canada)

“…Seasonal variations in water discharge may temporarily connect productive areas such as estuarine pools and riverine floodplains to main water masses (Gorski et al ; Davis et al ). However, a rapid decrease in water levels at the beginning of the life cycle may suddenly dewater or isolate spawning habitats from nursery areas (e.g., stranding) and result in massive egg and larvae mortality (Dumont and Fortin ; Fortin et al ; Žiliukiené and Žiliukas ). Moreover, interannual fluctuations in hydrological conditions may alter the spatial distribution of spawning habitats and nursery areas, which directly influences fish recruitment (e.g., Hufnagl et al ; Goto et al ).…”