The complete life cycle in captivity of the spider crab,Maja brachydactyla,Herbst 1788

Abstract

The present research describes the complete life cycle in captivity, including spawning, larval culture and fattening of juveniles until commercial size. Additionally, size, weight and age at each moulting stage were recorded, as well as zoeas biochemical composition. The most significant results obtained were as follows. Embryonic development lasted for 33 days. Each female had between three and five spawns, separated by 4–5 days each. Larval culture lasted for 20 days at 14–17°C. The zoeas turn to megalopa at ~11 days after hatch/DAH), and from megalopa to juvenile at ~20 DAH. Average survival was ~13%. Juvenile growth rate was higher during the first 8 months (0.22%–0.46% bw/day), and then gradually decreased when changing from live to frozen diets. Survival during the fattening phase was 63%. The final moult occurs at 450 DAH, when males and females have a carapace total length of 12.38 + 1.23 and 13.57 + 1.23 cm, respectively, and 541.56 + 104.26 and 670.68 + 162.6 g in total weight respectively. Biochemical composition of cultured zoeas showed a high amount of phospholipids and long‐chain fatty acids, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA). Low survival rates in larval culture and especially after passing to the benthic life style are the main problems regarding spider crab culture, and need to be improved.

Description of the larval and adult hindgut tract of the common spider crab Maja brachydactyla Balss, 1922 (Brachyura, Decapoda, Malacostraca)

“…The larval epithelial cells have squamous shape and abundant microvilli-like extensions, the latter are associated with the formation of new cuticle (Dillaman et al 2013), an expected role considering the short intermoult intervals during the larval development Pazos et al 2018). The larval epithelial cells show two characteristic features: epithelial-to-muscle cell hemiadherens junctions and bundles of fibres structures; both are associated with an arthropod cell type called "tendon cells", i.e.…”

Influence of temperature and light regime on the larval development of the common spider crab Maja brachydactyla Balss , 1922 (Brachyura: Majidae)

“…The maintenance of a light: dark cycle regime was also recommended for the larval culture of other brachyuran species (Gardner & Maguire, ; Minagawa, ). In culture conditions, the larval development of M. brachydactyla requires in average 31 days at 14–17°C (Pazos et al, ). In our optimized culture conditions, we are able to reduce the time of development to approximately 14 days.…”

“…The female fecundity is also very high (range 100,000–500,000 eggs per female depending on environmental and animal conditions: Rotllant, Simeó, Macià, & Estévez, ; Verísimo et al, ). The life cycle has been closed in captivity requiring 31 days in average to complete the larval development at 14–17°C (Pazos et al, ). The larval development of M. brachydactyla is abbreviated, comprising two zoeal stages (zoea I and zoea II) and a megalopal stage (Clark, ; Guerao et al, ).…”

Effects of co-supply ratios of swimming crab Portunus trituberculatus zoeae and Artemia on survival and growth of East Asian common octopus Octopus sinensis paralarvae under an upwelling culture system

“…A female M . brachydactyla can produce an average of 300,000 eggs per brood (Pazos et al, ; Verísimo et al, ); however, it has been concluded that use of M . brachydactyla (as well as the Mediterranean spider crab, Maja squinado ) zoeae as feed for juvenile octopus production was not viable because of the need to maintain a large number of M .…”

“…In fact, Iglesias et al (2014) suggested that a commercially available large-size decapod brachyuran, the spider crab Maja brachydactyla, might have potential as a feed source for the paralarvae of the Mediterranean common octopus O. vulgaris. A female M. brachydactyla can produce an average of 300,000 eggs per brood (Pazos et al, 2018;Verísimo et al, 2011); however, it has been concluded that use of M. brachydactyla (as well as the Mediterranean spider crab, Maja squinado) zoeae as feed for juvenile octopus production was not viable because of the need to maintain a large number of M. brachydactyla broodstock (Iglesias, Otero, Moxica, Fuentes, & Sánchez, 2004;Iglesias et al, 2014). At least 30 simultaneously ovigerous (egg-carrying) female crabs would be required for the production of 10,000 benthic juvenile octopuses if their zoeae could be successfully supplied in an upwelling culture system.…”