Comparison of Electronic Length Frequency Analysis (ELEFAN) for Estimation of Growth Parameters for Lollyfish, Holothuria (Holothuria) atra and Sand Sea Cucumber, Holothuria (Thymiosycia) arenicola (Holothuroidea: Echinodermata) in the North Arabian Sea, Pakistan

Abstract

To estimate the growth parameters, the non-seasonal von Bertalanffy and Hoenig seasonal von Bertalanffy models were fitted to the length frequency data of Holothuria atra and H. arenicola obtained from coastal areas of Karachi in the northern Arabian Sea, Pakistan between January and December 2014. The Hoenig seasonal von Bertalanffy growth parameters were estimated as L∞=36.1 cm total length (TL), K=0.75 year -1 for H. atra and as L∞=34.9 cm TL, K=0.70 year -1 for H. arenicola.H. atra individuals reached 73.9% of their maximum total length at the one year old. For H. arenicola it was calculated as 72.7%. Monthly mean growth rate of H. atra at the same ages was calculated higher than H. arenicola. The seasonal oscillation in growth rate for H. atra (C=0.50) was larger than it was for H. arenicola (C=0.37). The time of the year when the growth is slowest corresponded to the middle of April (WP=0.30) in H. atra and at the beginning of August (WP=0.60) in H. arenicola may be the result of the extended both reproduction and poor nutrition periods due to monsoonal effects on the marine environment. The relatively high growth rates (K>0.7 year -1 ) of these two species may have important implications for high survival rate, particularly in environmental condition where cause biological stress and marine confusion but may also increase their potential as a candidate species for aquaculture.

Estimating age and growth parameters for three commercial NE-Atlantic sea cucumbers, Holothuria mammata, H. forskali and H. arguinensis, in a marine protected area

“…On the other hand, it seems to negatively affect the growth of H. arguinensis and H. mammata. Since temperature seems to offset reproductive events for both these species (Marquet et al, 2017;Venancio et al, 2022) this relationship between growth and temperature is explained by an allocation of resources into reproduction, a phenomenon described for sea cucumbers (Ru et al, 2018;Ahmed et al, 2020).…”

“…Mortality could be due to predation of lower size class individuals or their inability to deal with physical stressors. A faster growth rate could be considered as an adaptive advantage since faster growth may have positive implications on mortality for some species (Ahmed et al, 2020). The models fit particularly well for the younger cohorts, however, this is not evident for older cohorts.…”

“…Natural mortality (M) was estimated with the two VBGF parameter (K, L ∞ ) based on the method from Then et al (2015) [33] with the TropFishR package (Mildenberger et al, 2017). Ageat-length was back calculated from length using the seasonal estimated VBGF function, according to Equation 2 (Ramıŕez-Gonzaĺez et al, 2020) and finally, mean monthly growth rate was calculated as averages over the previous 12 months for age groups (Wilhelm et al, 2017;Ahmed et al, 2020).…”

“…Therefore, H. forskali may be more susceptible to seasonality that influences food quantity and quality. Temperature has been known to be a factor regulating the reproductive cycle of holothurians (Ahmed et al, 2020) and increase metabolism. In the study area, the temperature began increasing in January, peaking in October, but being generally higher during summer months (Feĺix et al, 2021;Venancio et al, 2022).…”

Seasonal population patterns of Holothuria Arenicola Semper, 1868 from Karachi coast, Northern Arabian Sea

“…arenicola show rapid and seasonal growth characteristics (Ahmed et al, 2020). Allometric growth has been determined when the data are examined.…”