Latitudinal and stock-specific variation in size- and age-at-maturity of female winter flounder, Pseudopleuronectes americanus, as determined with gonad histology

Investigating spatial variation and temperature effects on maturity of female winter flounder (Pseudopleuronectes americanus) using generalized additive models

“…This rationale is based on differences in meristics, life history characteristics, and movement patterns (DeCelles and Cadrin 2011; Northeast Fisheries Science Center 2011). Recent studies have reported evidence of substantial variation in maturity schedules within stock regions (McBride et al 2013), which suggests the need to assess such variation at a finer spatial scale.…”

“…With the exception of the offshore GB stock, which exhibits faster growth and larger sizes-at-maturity than the two inshore stocks (Pereira et al 1999;McBride et al 2013), trends in winter flounder life history parameters generally follow a latitudinal pattern paralleling along-shore temperature gradients. Fish at the southern end of the species' exploitable US range tend to grow faster and mature at earlier ages (estimated median age at maturity of 2.4 years) than those in the northern GOM (4.7 years; McBride et al 2013). The timing of spawning follows a similar gradient, with fish in SNE and GB stock areas spawning earlier in the species' winter-to-spring spawning season (November-April) than those in the GOM (April-June; Pereira et al 1999;Press et al 2014).…”

Reproductive dynamics of Pacific sanddab, Citharichthys sordidus, off the central coast of California

“…Additionally, the smallest fish with vitellogenic oocytes in Chamberlain's study (1979;160 mm) was still nearly 50 mm larger than that reported here. Within a species, increasing size and age at maturity with increasing latitude is common (McBride et al, 2013) and may be associated with temperature variability (Felix et al, 2011;Militelli, 2011;Sampson and Al-Jufaily, 1999). However, geographic variability between this and Arora's study is unlikely to fully explain the magnitude of the shift, as the sampling locations are separated by b100 km.…”

Reproductive biology of largescale tonguesole Cynoglossus arel in coastal waters of Bandar Abbas, Persian Gulf, Iran

“…This study complements earlier work on large-scale tonguesoles by including macroscopic analyses of maturation and reproductive condition, but also focuses on the gonad histology using microscopic techniques (Narimatsu et al, 2007). Gonad histology, although more costly and time-consuming than macroscopic analyses, can provide an independent assessment of maturity and a more detailed insight into the process of oogenesis (McBride et al, 2013).…”

“…Large empty lobular spaces are present in testes, except for some residual sperm sexes, we calculated indices of standardized gonad weight and standardized gonad length, following definitions of McBride et al (2013). Standardized gonad weight was defined as gonad weight/(ovary-free body weight) × 100, or GW/(BW − GW) × 100 (n = 905).…”