Reproductive pattern and population dynamics of commercial red swamp crayfish (Procambarus clarkii) from China: implications for sustainable aquaculture management

Abstract

BackgroundThe red swamp crayfish, Procambarus clarkii (Girard, 1852), is one of the most promising freshwater species for aquaculture in China. Understanding its reproductive pattern and population dynamics is crucial for sustainable management, but there is currently a lack of fundamental knowledge of commercial P. clarkii populations. Therefore, the purpose of this study was to investigate the reproductive pattern and population dynamics of commercial P. clarkii throughout the yearly cycle.MethodsA total of 2,051 crayfish (1,012 females and 1,039 males) were collected from March 2016 to February 2017 in the area of Selection and Reproduction Center of Crayfish. The reproductive pattern was evaluated by the gonadosomatic index (GSI), hepatosomatic index (HSI), ovarian development and fecundity. Growth, mortality rates and exploitation rate were estimated by electronic length frequency analysis by R package “TropFishR” based on data of cephalothorax length (CTL).ResultsOur results demonstrated that spawning activities of P. clarkii took place from September to November, with a mean fecundity of 429 ± 9 eggs per female. There were two recruitments yearly, a major one from October to November and a minor one from March to May. With respect to population growth, five growth cohorts were identified for both females and males. Crayfish grew faster but attained smaller asymptotic maximum CTL as indicated by higher growth coefficient (K), growth parameter index (Ø′) and lower asymptotic CTL (Linf). The estimates of total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 1.93, 1.02, 0.91 year−1 for females and 2.32, 0.93, 1.39 year−1 for males, which showed that the mortality of male crayfish was mainly caused by fishing. The estimates of exploitation rate (E) indicated that male crayfish were overexploited, with the values of 0.47 and 0.60 year−1 for females and males, respectively.DiscussionP. clarkii spawned from September to November while two recruitments were observed yearly. We inferred that some eggs, prevented from hatching by low water temperature in winter, were more likely to hatch in the next spring. Moreover, the fishing mortality rate was relatively high for males, which might be related to the males-directed selection during the reproductive period. The higher values of exploitation rate in our study confirmed that males P. clarkii were overexploited and were under high fishing pressure. We thus suggest reducing fishing intensity on immature crayfish and avoid sex selection during the reproductive period to improve the overall sustainability of commercial P. clarkii populations.

Comparative transcriptomic analysis of the different developmental stages of ovary in red swamp crayfish Procambarus clarkii

“…At present, P. clarkii farming has become an important industry in China, with production reaching 1,638,700 tons and a total output value of 369 billion China Yuan (CNY) in 2018 [15]. Some successful reproductive results for commercial P. clarkii have been reported from areas such as Qianjiang, Hubei province, where breeding grounds of P. clarkii in China, extend over 200 ha and enclose a variety of artificial ponds [16]. The red swamp crayfish-rice culture is the major model for production of P. clarkii in China, a farming scheme that not only makes significant improvements in rural livelihood and food security but also contributes to eco-environmental benefits and sustainable development [17].…”

Genetic Diversity Evaluation and Population Structure Analysis of Red Swamp Crayfish (Procambarus clarkii) from Lakes and Rice Fields by SSR Markers

“…Qianjiang City of the Hubei province has been recognized as the hometown of red swamp crayfish in China by the Ministry of Agriculture of the People's Republic of China [57]. The artificial breeding and culture model of crayfish is considered to be a popular model of crayfish production [5].…”

Molecular cloning and expression analysis of Dmc gene related to gonadal development in Procambarus clarkii

“…Procambarus clarkii is commonly known as red swamp crayfish, and it has now become an important economic species with 0.3 million hm 2 husbandry area and gross production of 0.6 million tons in China (Wang et al., 2019; Xiao et al., 2017). With the rapid expansion of domestic aquaculture scale, some problems such as depressed germplasm have occurred with P. clarkii , resulting in retarded growth (miniaturized), diminished fertility and decreased disease resistance (Jin et al., 2019; Wang et al., 2019; Xiao et al., 2017). These problems have become important bottlenecks for impeding the sustainable development of aquaculture industry of P. clarkii (Chen, 2020; Tan et al., 2017).…”