Evaluation of ageing precision from different structures of three threatened freshwater fish species,<i>Clarias batrachus</i>,<i>Heteropneustes fossilis</i>and Wallago attu

Khan, Shahbaz; Khan, Mohammad Afzal; Miyan, Kaish

doi:10.25225/fozo.v62.i2.a3.2013

Cited by 5 publications

(2 citation statements)

References 23 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ability to discern annual growth in aging studies is essential to understanding population dynamics, such as recruitment, longevity, and mortality (Campana ; Khan et al. ). One method of validating annual growth is by use of a chemical marking agent, such as OTC (Nielson ).…”

Section: Discussionmentioning

confidence: 99%

Age and Growth of Juvenile Atlantic Sturgeon in the Lower Hudson River

Kehler

Sweka

Mohler

et al. 2018

N American J Fish Manag

View full text Add to dashboard Cite

The precipitous decline of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus coupled with their recent listing under the U.S. Endangered Species Act necessitates investigations into their population dynamics. Our objectives were to (1) estimate age of juvenile Atlantic Sturgeon by using pectoral spine sections; (2) determine annual growth periodicity in hatchery-reared and recaptured wild Atlantic Sturgeon to validate our aging method; (3) determine growth rates for recaptured juveniles; and (4) back-calculate lengths from ages estimated by using pectoral spine sections from captured juveniles. Fish were captured via gillnetting in Newburgh and Haverstraw bays, Hudson River, during fall 2003, spring and fall 2004, and spring and fall 2005. Two readers agreed upon 91% (n = 474) of ages estimated for juvenile Atlantic Sturgeon, establishing a coefficient of variation of 1.7%. Eight year -classes (ages 1-8) were represented, with age-4 fish making up the largest age-class (39%; n = 203) and age-1 fish being the least represented (<1%; n = 4). Multi-annual oxytetracycline injections in four cohorts of hatchery-reared Atlantic Sturgeon (n = 34) demonstrated a two-part zone for each year of growth, as did four recaptured juveniles that were at liberty for a least 1 year, which exhibited mean growth rates of 0.3 mm/d and 2.4 g/d. We back-calculated median FLs from annulus positioning in ages 2-8 by using dorsal and ventral lobes of pectoral spine sections and compared the results to actual reported lengths. Dorsal and ventral lobes underestimated the median FLs of all age-classes except ages 3 and 7, for which lengths were overestimated. We found statistical differences between dorsal-and ventral-derived median FLs, suggesting that both regions must be evaluated. Our overall goal is to provide researchers with a baseline of age and growth data for future work on juvenile Atlantic Sturgeon.

show abstract

Section: Discussionmentioning

confidence: 99%

Age and Growth of Juvenile Atlantic Sturgeon in the Lower Hudson River

Kehler

Sweka

Mohler

et al. 2018

N American J Fish Manag

View full text Add to dashboard Cite

show abstract

“…Total number of samples (N = 486) remains the same for each ageing structure the most suitable ageing structure in a number of fish species such as Pylodictis olivaris (Nash & Irwin, 1999), Ictalurus punctatus (Buckmeier, Irwin, Betsill, & Prentice, 2002), Clarias gariepinus (Khan, Khan, & Miyan, 2011) and Channa punctatus (Khan et al, 2013b). Khan, Khan, and Miyan (2013a) reported otoliths as the most time-efficient and precise means of age estimates in Clarias batrachus compared to vertebrae and pectoral spines. In the present study scales also showed a good value of agreement between age readers because annuli were clear and easy to read and have been the most widely used ageing practice for the majority of cyprinids (Kamilov, 1984), primarily due to advantages such as the ease of collection and preparation, and more importantly, because the method is non-destructive to fish F I G U R E 4 Age bias graphs for C. striata (N=486) age estimates from sectioned otoliths versus (a) whole otoliths, (b) scales, (c) opercular bones, (d) vertebrae, (e) cleithra and (f) fin rays.…”

Section: Discussionmentioning

confidence: 99%