Influences of feeding habitat and age composition on the growth patterns, length-frequency and gut contents in maternal paddlefish Polyodon spathula (Walbaum, 1792). | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 24, Volume 24, Issue 5, July and August 2020, Pages 361-374 PDF (1.05 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2020.106609 | ||
| Authors | ||
| Mahmoud Elnakeeb; Lydia M. Vasilyeva; Natalia V. Sudakova; Adelya Z. Anokhina; Ahmed G. A. Gewida | ||
| Abstract | ||
| The study aims to study the impact of the diet shift and feeding behavior of the paddlefish different age groups on the growth during the spawning season. Habitat affected paddlefish prey selection or foraging success is a striking force that promotes either dominance or submissiveness of brood fish to reproductive or growth performance under Russian aquaculture conditions. Four age groups were studied depending on years of commissioning (age composition: 23, 18, 17, 16; for years 1997, 2002, 2003 and 2004, respectively) and registered divergence in their growth rates throughout spawning season 2020. Growth patterns of 59 mature paddlefish were studied based on length-weight relationship, length frequency, and the growth coefficient (K). The results revealed that moderate growth pattern was observed in the 2nd group Isometric (b = 3), whereas the rest groups recorded negative allometric growth (b < 3). The data obtained from gut contents were consistent with the previous growth performance results. Major five prey categories (benthic macro-invertebrates, macro-invertebrate larvae, detritus, zooplankton and phytoplankton) were observed within fish stomach, which exposed through natural feeding in the rearing ponds. The values of chi-square test (χ2) results showed that frequencies in one or more prey items of a four age were strong significance (p-value = 8.93E-17 & χ2 = 1.219, 1.051, 1.066 & 1.032; for 2nd, 3rd, 4th and 1st, respectively). Overall results propose maternal paddlefish prey election and growth patterns can be highly variable, and merely heavily reliant on feeding habitat and swimming behavior across spawning season. | ||
| Keywords | ||
| Diet shift; Growth patterns; Gut contents; Paddlefish; Polyodon spathula; Spawning season | ||
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