Role of Sex Ratio and Density on Fertilization Success of Intensively Cultured Endangered Woundfin

Abstract

Woundfin Plagopterus argentissimus are a small, endangered cyprinid found solely in the Virgin River across Utah, Arizona, and Nevada. As of now, only three facilities culture Woundfin for conservation propagation purposes, but there is growing concern that current extensive culture protocols are not meeting the conservation recovery goals outlined in the Virgin River Resource Management and Recovery Program. The development of alternative rearing methodology, like effective intensive culture conditions, could help increase production to more effectively meet the conservation propagation needs for this species. Our goal was to assess the effect of different sex ratios and fish densities on reproductive success at indoor facilities. We measured fertilization success at three different sex ratios (1:1, 1:3, 1:5; female:male) and three different fish densities (0.05, 0.21, and 0.47 fish/L) in a laboratory setting. Sex ratio did not significantly affect fertilization success (P = 0.73). Fertilization was completely inhibited at a density of 0.05 fish/L, but there was no difference in fertilization success between the two other density treatments (P = 0.92). Our findings suggest that a density greater than 0.05 fish/L and a sex ratio of 1:1, 1:3, or 1:5 will likely enhance fertilization success. The results and conclusions of this paper provide valuable rearing information for the Virgin River Resource Management and Recovery Program and hatchery managers attempting to increase production of Woundfin in an intensive culture setting.

REPRODUCTIVE ASPECT OF TINY SCALE BARB, Thynnichthys thynnoides (BLEEKER, 1852) AT RUI RIVER, PERAK, MALAYSIA

“…However, the study on Hemibagrus menoda by Jega et al (2018) at the Kangsha River, Netrakona, Bangladesh, found that the sex ratio of the species was female-biased (1.30:0.97), implying the non-existence of seasonality in sex distribution. Laboratory fertilization on Plagopterus argentissimus; a small, endangered cyprinid, found that a sex ratio of 1:1, 1:3, or 1:5 (female: male) will likely heighten fertilization success (Maskill et al, 2017). Results from respective studies and the Chi-square homogeneity test may suggest that T. thynnoides in the studied areas can still thrive.…”

“…In fishery management practices, estimation of fish sex ratio (i.e., ready-to-mate females to ready-tomate males or vice versa (de Jong et al, 2009;Maskill et al, 2017) may assist in determining whether the population is in a standard or abnormal condition. A healthy fish population in its natural habitat usually has a sex ratio of 1:1 (Neves et al, 2020).…”

Patterns of fish community structure in protected and non-protected marine areas of mainland Tanzania

“…A higher female to male sex ratio increases fertilization success and productivity (Maskill et al, 2017).…”

SOME BIOLOGICAL ASPECTS OF SKIPJACK TUNA (Katsuwonus pelamis LINNAEUS, 1758) DI PERAIRAN TOLI-TOLI WATERS, CENTRAL SULAWESI

“…Based on the chi-square test, the female and male tuna ratio is statistically in an unbalanced state. Understanding sex ratio is related to maintaining the sustainability of fish populations (Budd et al, 2015;Fryxell et al, 2015;Madenjian et al, 2016;Benevenuto et al, 2017;Maskill et al, 2017;Provoost et al, 2017). Therefore, it is expected that the ratio of male and female fish is balanced.…”