--- Not for reuse or distribution --- 8 INLAND CRUSTACEAN FISHERIES Miles Abadilla, W. Ray McClain, Taku Sato, Luis M. Mejía- Ortíz, and Miguel A. Penna- Díaz Abstract Freshwater crustacean inland fisheries are typically confined to small local areas that are associ- ated with bodies of water, like rivers and swamps. They are small- scale fisheries, enough to supply the requirements for local commercial use, and considered mainly as a subsistence resource for small fishing communities. As such, inland crustacean fisheries exemplify a subsistence op- portunity for small countries with limited economic power, particularly rural communities. Crustaceans are a relevant protein source alternative to fish, and they are often also associated with local gastronomical and cultural identity. Data for the most commonly caught species are often unavailable since these fisheries exist in remote areas where government or institu- tional monitoring is limited, making it difficult to obtain reliable data about small- scale fisheries. Nonetheless, the captured species and the techniques used are widely diverse. In inland fisheries, the main target species are prawns from the genus Macrobrachium, gathered within the tropics all over the world. Natural fisheries of crayfishes in their native range exist on several continents, with Procambarus clarkii, Pacifastacus leniusculus, and Astacus astacus as the main commercial species. Some of them have1 also become a fisheries resource in areas where they were introduced. The only terrestrial crab fishery is for an anomuran, the coconut crabBirgus latro. The future of most of these fisheries depends in part on the health of the water sources threatened by con- tamination and unrestricted waterways jeopardized by the construction of dam- like structures that block the migration of some species to complete their reproductive cycles. The creation of regulatory policies is key for keeping the fishery activity self- sustainable because most of the exploitation depends on wild populations. There are some conservation efforts implemented thanks to the relevant gastronomical value of the species, as well as to economically sustain local communities in remote areas. Miles Abadilla, W. Ray McClain, Taku Sato, Luis M. Mejía-Ortíz, and Miguel A. Penna-Díaz, Inland Crustacean Fisheries In: Fisheries and Aquaculture. Edited by: Gustavo Lovrich and Martin Thiel, Oxford University Press (2020). © Oxford University Press. DOI: 10.1093/oso/9780190865627.003.0008 182 --- Not for reuse or distribution --- 182 Fisheries and Aquaculture INTRODUCTION Crustaceans are fished not only in the marine environment but also in inland habitats such as lakes, rivers, and swamps, as well as on land, where some terrestrial crustaceans are caught for either com- mercial or subsistence use. The global catch data of these freshwater and semi- terrestrial inland crustaceans tend to be undocumented because most of this activity constitutes small- scale artisanal or subsistence fisheries that exploit local crustacean species (Welcomme 2011). Likewise, research on these fisheries is also largely lacking (New et al. 2000). For example, in southern central Chile, the crayfish Samastacus spinifrons is harvested in rivers and lakes through a variety of methods and then sold locally. However, no data exist on their catch since Chilean fishery regulations do not rec- ognize this species as a fishery resource (Rudolph 2013a). Similarly, in the myriad islets of the trop- ical Indo- Pacific region, the coconut crabBirgus latro is traditionally and locally consumed, yet little is known about the harvest sizes across the different islands and countries (Sato and Yoseda 2010). Inland crustaceans are extremely diverse, with different species, lifestyles, life histories, and re- productive biology, influencing the extent of human exploitation. Many freshwater crustaceans, such as all freshwater crabs, have direct development (i.e., there is no larval stage during develop- ment, with the embryo developing into an adult-lik e juvenile) (Strathmann 2018). Direct devel- opment limits the dispersal ability of these species relative to their counterparts that have indirect development, which includes a free- living larval stage for dispersal into other habitats. Hence, the habitat range and geographic distribution of landlocked species are also usually restricted to a spe- cific water body or region; consequently, only local communities may encounter and harvest these crustaceans for subsistence or for small- scale commercial use. In some large- scale inland crusta- cean fisheries, such as the Chinese mitten crabEriocheir ( sinensis), the effect of lower natural catch sizes has been bolstered by farmed production during the final decades of the twentieth century. Currently, most, if not all, industrial- scale exploitation of inland crustaceans is dependent on aqua- culture, which has largely exceeded wild capture yields to meet global demand (New et al. 2000, Sui et al. 2011). In this chapter, we explore inland terrestrial and freshwater crustacean fisheries that are eco- nomically important to the regions where these crustaceans occur. The following sections detail se- lect crustacean fisheries that are most representative of the main crustacean groups: prawns, crabs, and crayfishes. Each case study highlights the biological and ecological features that allow these organisms to be suitable for capture fisheries in their location, management practices (if any), and the future outlook for the species. FRESHWATER PRAWNS Prawns of the genus Macrobrachium belongs to the family Palaemonidae and are distributed mainly in tropical and subtropical regions. There are over 240 recognized species ofMacrobrachium around the world (Wowor1 et al. 2009). Approximately 190 species are diadromous, and 50 of them have di- rect development. The distribution limits for these species are at 35º of latitude in both hemispheres (Anger 2013), and they inhabit four continents: the Americas, Africa, Asia, and Oceania (Fig. 8.1). Their habitats are diverse since there are species living in caves, springs, streams, and rivers, and they can also be found in freshwater or coastal lagoons with variable salinities. The recent discoveries of new species in caves, groundwater systems, wetlands, or other isolated areas suggest that this group may be experiencing ongoing speciation (Komai and Fujita 2005, Dos Santos et al. 2013, Cai and Vidthayanon 2016). Prawns are common in the tropical and subtropical rivers with access to the sea. There are two main groups: the first is composed of species that can conquer new ecological niches, have fast --- Not for reuse or distribution --- Inland Crustacean Fisheries 183 Fig. 8.1. Global records of the Macrobrachium spp. and their distribution ranges based on global records. Black dots rep- resent coordinates and centroids of the current records for Macrobrachium spp. as of June 12, 2019. Figure modi- fied after the map generated by Discover Life’s (2019) Global Mapper using the database of Global Biodiversity Information Facility (1,524); CNCR [Colección Nacional de Crustaceos] (730); Australian Museum provider for OZCAM (196); Rapid Assessment Program (RAP) Biodiversity Survey Database (163); NMNH Invertebrate Zoology Collections (119); Albany Museum (59); Collection Crustacea, ZMB (52); CAS Invertebrate Zoology (IZ) (50); invertebratezoology (44); Museum of Comparative Zoology, Harvard University (40); Field Museum of Natural History (Zoology) Invertebrate Collection (39); Invertebrates (GBIF- SE:SMNH) (29); Peabody Invertebrate Zoology DiGIR Service (2); Crustaceans specimens (2); Atlantic Reference Centre (OBIS Canada) (1); and iNaturalist (55). Numbers in parenthesis are records from each database. growth, and produce many offspring, with free- living larval stages in brackish and marine waters. The larvae develop in the sea until reaching the juvenile stage. From there, juveniles move from the coastal areas and migrate upstream to rivers to grow and reproduce, making them a diadromous species (Bauer 2013). A second group involves species with direct development, which do not need brackish or seawater in their first free- living stage (Jalihal et al. 1993, Anger 2013, 2016). Diadromous prawns produce higher yields since these species are larger in size, adding to their value and attractiveness to locals. Species with direct development are generally smaller and can only be found in local markets, mainly consumed by the local indigenous people (Mejía- Ortíz et al. 2016, Tejeda- Mazariegos et al. 2018). Macrobrachium rosenbergii (Fig. 8.2) is widely cultivated be- cause this species has an important international market, with an estimated annual production of more than 200,000 t (New 2014; see Chapters 4 and 9 in this volume). However, its introduction for aquaculture in the different rivers of the USA, Mexico, Brazil, India, Vietnam, Indonesia, and China (New 2014) has caused 1ecological problems, affecting the native and endemic fauna (Bowles et al. 2000, Pérez et al. 2003, Magalhaes et al. 2005, Silva- Oliviera et al. 2011). In order to avoid new ecolog- ical catastrophes, there are efforts to cultivate native prawn species of economic interest within their native distribution ranges. These include M. carcinus, M. tenellum, M. acanthurus, M. americanum, M. amazonicum, and M. surinamicum in the Americas; M. macrobrachion and M. vollenvhovenii in Africa; M. rosenbergii, M. nipponense, M. malcolmsonii, M. idella, and M. lamarrei in Asia (New 2005;