12 May 2020

Celebrate diversity: All females, all prawns

Ars Technica has a big feature article on all female crustaceans being used for food, but it’s not Marmorkrebs.

Marmorkrebs are being used as food in Madagascar (see Andriantsoaet al. 2019, 2020) and there is interest in developing them for commercial aquaculture (Jurmalietiset et al. 2019), but there is not much of an existing market for crayfish this small.

Freshwater prawns (Macrobrachium rosenbergii) are another matter. They are widely cultivated and harvested for food in many countries. There was a challenge on The Amazing Race (American version, Season 31, Episode 3) where teams caught them from an indoor fishing center in Vietnam.

I hadn’t been paying close attention to a company called Enzootic that has created a way of making prawns all female. Unlike Marmorkrebs, which are genetically distinct, this company takes advantage of plasticity in sex determination in this species:

It starts by surgically extracting the hormone-producing organ from “donor” males, which are then broken down into individual cells. When the cells are injected into young females, the hormones they produce cause the females to develop as males, despite their chromosomes. Just like natural male prawns, they can mate normally with other females, but some of their offspring possess a unique trait. Known as “super females,” they produce offspring that will develop as females regardless of the chromosomes they carry.

Enzootic has set up the genetics of its shrimp so that these super females are relatively easy to identify, and they can be used to quickly produce large populations of nothing but females.

Some technical papers on this process are Sagi and Aflalo (2005) Mohanakumaran et al. (2006), and Levy et al. (2017).


Andriantsoa R, Jones JPG, Achimescu V, Randrianarison H, Raselimanana M, Andriatsitohaina M, Rasamy J, Lyko F. 2020. Perceived socio-economic impacts of the marbled crayfish invasion in Madagascar. PLOS ONE 15(4): e0231773. https://doi.org/10.1371/journal.pone.0231773

Andriantsoa R, Tönges S, Panteleit J, Theissinger K, Carneiro VC, Rasamy J, Lyko F. 2019. Ecological plasticity and commercial impact of invasive marbled crayfish populations in Madagascar. BMC Ecology 19(1): 8. https://doi.org/10.1186/s12898-019-0224-1

Jurmalietis R, Grickus A, Elstina A. 2019. Marbled crayfish (Procambarus virginalis) as a promising object for aquaculture industry. In: Environment. Technology. Resources. Proceedings of the 12th International Scientific and Practical Conference, Volume 1, pp. 92-95. http://dx.doi.org/10.17770/etr2019vol1.4174

Levy T, Rosen O, Eilam B, Azulay D, Zohar I, Aflalo ED, Benet A, Naor A, Shechter A, Sagi A. 2017. All-female monosex culture in the freshwater prawn Macrobrachium rosenbergii – A comparative large-scale field study. Aquaculture 479: 857-862. https://doi.org/10.1016/j.aquaculture.2017.07.039

Mohanakumaran Nair C, Salin KR, Raju MS, Sebastian M. 2006. Economic analysis of monosex culture of giant freshwater prawn (Macrobrachium rosenbergii De Man): a case study. Aquaculture Research 37(9): 949-954. https://doi.org/10.1111/j.1365-2109.2006.01521.x

Sagi A, Aflalo ED. 2005. The androgenic gland and monosex culture of freshwater prawn Macrobrachium rosenbergii (De Man): a biotechnological perspective. Aquaculture Research 36(3): 231-237. https://doi.org/10.1111/j.1365-2109.2005.01238.x

External links

Can gender-bending Israeli superprawns help feed the world?

No comments: