Biology, distribution, conservation status and stocking perspective of freshwater crayfish in Greece: An updated review

Abstract

Freshwater crayfish are among the most important aquatic inhabitants in terms of ecosystem integrity retention. Although Astacus astacus and Pontastacus leptodactylus are characterized by the IUCN as vulnerable and least concern, respectively, Greek official data and local authorities report them as highly endangered or threatened at local levels. Therefore, all freshwater crayfishing activities from the main producing areas in Greece have been forbidden for 1 year since August 2021. Since aquaculture in Greece remains primarily focused on marine freshwater fish, freshwater crayfish aquaculture establishment is expected to provide a promising alternative for regional economic development and a solution to unemployment. Under this prism, the present study represents a comprehensive review of the most important features related to biology, distribution, aquaculture methods, economic importance and research progress considering both stocking perspectives and conservation strategies of those two crayfish species. Recent measurements by local authorities for the protection of the freshwater crayfish populations are described and evaluated. Freshwater crayfish aquaculture is expected to be beneficial for Greece, a country that covers all requirements for this sector. The updated information regarding these two species, summarizing the existing literature towards aquaculture conditions, poses suggestions and presents future perspectives on this field.

Effects of dietary substitution of fishmeal by black soldier fly (Hermetia illucens) meal on growth performance, whole-body chemical composition, and fatty acid profile of Pontastacus leptodactylus juveniles

“…Apart from being keystone species and ecosystem scavengers ( Usio and Townsend, 2008 ) freshwater crayfish possess a high economic and cultural value since ancient times ( Koutrakis et al, 2009 ) and nowadays crayfish catches reach high prices ( Ackefors, 1998 ; Jussila et al, 2015 ). Also, more recently, in Northern Greece crayfish festivals take place in an annual base ( Alvanou et al, 2022 ), reflecting its high economic importance at a local level. Its high value in human diet is not only attributed to the high content and quality of proteins and fats but also to its consumption during fasting periods complying with religious guidelines ( Jö, 2004 ; Patoka et al, 2016 ).…”

“…Pontastacus leptodactylus is a native species in northeastern Greece. However, due to its high economical value and its export potential, which led to overfishing, its population in lake Vegoritida and lake Polyphytou in Northern Greece seems to decline ( Alvanou et al, 2022 ). Freshwater crayfish populations’ declines have been observed in several studies ( Bolat, 2001 ; Harlioğlu and Harlioğlu, 2009 ; Souty-Grosset and Reynolds, 2009 ) and in most cases were attributed to a combination of overfishing, pollution and habitat loss or destruction ( Edsman et al, 2010 ; Karimpour et al, 2011 ).…”

“…As the demand for decapod crustacean fisheries is growing globally ( Boenish et al, 2022 ), it is estimated that the fishing rates will increase even more leading to overexploitation of wild stocks and the devastation of the native populations. Hence, it is of major importance to develop a rearing protocol for both restocking purposes and coverage of global consumption demands for crustaceans ( Pantazis et al, 2015 ; Seemann et al, 2015 ; Alvanou et al, 2022 ).…”

Probiotics, Prebiotics, and Synbiotics Utilization in Crayfish Aquaculture and Factors Affecting Gut Microbiota

“…Crustaceans are considered one of the foods with the fastest worldwide growth rates. Crayfish aquaculture apart from having a lower carbon footprint in comparison with other fish aquaculture practices, also contributes to the development of the regional economy [ 9 ]. Crustaceans, which in less than two decades tripled the world’s shrimp production output, are considered among the foods with the fastest worldwide growth rates, according to the Boston Consulting Group’s (BCG) most recent report [ 10 ].…”

“…Crustaceans, which in less than two decades tripled the world’s shrimp production output, are considered among the foods with the fastest worldwide growth rates, according to the Boston Consulting Group’s (BCG) most recent report [ 10 ]. Although crayfish aquaculture exhibits lower production quantities compared to shrimp aquaculture [ 11 ], its potential to be both economically and environmentally beneficial is considerable [ 9 ]. Specifically, China has reported rapid development in its crayfish farming sector, with outputs exceeding 1 million tons in 2018 [ 12 ].…”