Morphological parameters of Siberian shrimp larvae Exopalaemon modestus (Heller) in warm- water aquaculture

Freshwater shrimp species with a shortened larva development period are suitable for acclimatization into cooling ponds of energy facilities, both to enrich their food base and for cultivation. Siberian shrimp Exopalaemon modestus (Heller) are characterized by a wide range of ecological plasticity and a high survival rate of larvae with two zoea stages, making them a promising object for this purpose. In this regard, the anatomo-morphological indices, body structure, size characterization of zoea stages 1 and 2, as well as the postlarvae stage, when reared on discharged heated water of a thermal power plant, are described in detail. The larvae were reared in production conditions of the hatchery in aquaria equipped with drainage devices, where water was continuously supplied from the warm channel of Berezovskaya Thermal Power Station (TPS) (Brest region, Belarus) at a temperature of 20–22 ℃ and an initial planting density of 10 eggs/liter. In these conditions, the mean duration of larval development was 7 days, which is 1 day longer than during rearing in laboratory conditions in brackish water (3.12–4.03 ‰) and at temperatures of 26–28 ℃. In this regard, anatomo-morphological parameters, body structure, and size characteristics of the 1^st and 2^nd stages of zoea and postlarvae stages during rearing on the discharge heated water of the thermal power plant are described in detail. The average length of larvae of the first zoea stage was 4.08 ± 0.12 mm, of the second stage was 4.47 ± 0.23 mm, and of the postlarvae stage was 4.70 ± 0.26 mm. On average, the inter-larval period for the 1^st and 2^nd zoea stages lasted two days, while the postlarvae stage, it averaged at three days. The general identifying characteristics for these stages of ontogenesis were: the structure of the eyes, antennules, pereopods, pleopods, rostrum, and carapax. The original drawings and lengths of rostrum, eyes, carapax, antennae, antennules, mandibles, maxillae, maxillapedes, pereopods, pleopods, and telson are provided.

1. Kurenkov I. I. Towards a biology of Far Eastern freshwater shrimps. Trudy Amurskoi ikhtiologicheskoi ekspeditsii 1945‒1949 gg. [Proceedings of the Amur ichthyological expedition 1945‒1949]. Moscow, 1950, vol. 1, pp. 379–390 (in Russian).

2. Oh C.-W., Lim H.-S., Suh H.-L., Ma C.-W., Park K.-Y. Growth and reproductive biology of the freshwater shrimp Exopalaemon modestus (Decapoda: Palaemonidae) in a lake of Korea. Journal of Crustacean Biology, 2002, vol. 22, no. 2, pp. 357–366. https://doi.org/10.1651/0278-0372(2002)022[0357:GARBOT]2.0.CO;2

3. Guo Z. L., Wang X. Q., Zhang J. P. On the genus Exopalaemon (Decapoda, Caridea, Palaemonidae) in Guangdong province, Southern China. Crustaceana, 2005, vol. 78, no. 7, pp. 839–850. https://doi.org/10.1163/156854005774445537

4. Khmeleva N. N., Kulesh V. F., Alekhnovich A. V., Giginyak Yu. G. Ecology of freshwater shrimps. Minsk, Belaruskaya navuka Publ., 1997. 254 p. (in Russian).

5. De Grave S., Mann D. J. The first record of Exopalaemon modestus (Heller, 1862) (Decapoda, Palaemonidae) in Kazakhstan. Crustaceana, 2012, vol. 85, no. 12–13, pp. 1665–1667. https://doi.org/10.1163/15685403-00003144

6. Temreshev I. I., Esenbekova P. A., Kozhabaeva G. E., Isenova G. Zh., Slivinskii G. G. About distribution the freshwater shrimps (Crustacea, Decapoda, Palaemonidae) in water bodies of south Kazakhstan and opportunities of their use as biogeoindicators of the condition of aquatic ecosystems. Izvestiya Natsional’noi akademii nauk Respubliki Kazakhstan. Seriya biologicheskaya i meditsinskaya [News of the National Academy of Sciences of the Republic of Kazakhstan. Biological and medical series], 2017, vol. 2, no. 320, pp. 215–223 (in Russian).

7. Emmett R. L., Hinton S. A., Logan D. J., McCabe G. T. (jr.). Introduction of a Siberian Freshwater Shrimp to Western North America. Biological Invasions, 2002, vol. 4, no. 4, pp. 447–450. https://doi.org/10.1023/A:1023641915417

8. Zeug S., O’Leary G., Sommer T., Harrell B. Introduced palaemonid shrimp invades the Yolo Bypass floodplain. IEP Newsletter, 2002, vol. 15, no. 1, pp. 13–15.

9. Hu T. J., Ye T. Y., Zhang Z. M, Wei X. K., Xu Z. K. Pond rearing on Exopalaemon modestus. Science Fish Farming, 2002, no. 2, р. 31.

10. Li X.-Z, Liu R.-Y., Liang X.-Q. The zoogeography of Chinese Palaemonoidea fauna. Biodiversity Science, 2003, vol. 11, no. 5, pp. 393–406. https://doi.org/10.17520/biods.2003047

11. Anger K. The biology of decapod crustacean larvae. Lisse, The Netherlands: A. A. Balkema Publ. 2001, vol. 4. 419 p.

12. Kulesh V. F. Cultivation biology of commercial freshwater shrimp and river crayfish species in warm waters. Moscow, Nowoe znanie Publ., 2012. 328 p. (in Russian).

13. Kulesh V. F. Growth and survival of larvae of the freshwater shrimp Exopalaemon modestus (Heller) in the discharge water of a thermal power plant. Doklady Natsional’noi akademii nauk Belarusi = Reports of the National Academy of Sciences of Belarus, 2009, vol. 53, no. 4, pp. 82–87 (in Russian).

14. Kulesh V. F. Peculiarities of the life cycle of freshwater shrimps with abbreviated larval development. Hydrobiological Journal, 2020, vol. 56, no. 4, pp. 43–59. https: //doi.org /10.1615 /hydrobj.v56.i4.40

15. Kwon C. S., Uno Y. The larval development of Palaemon modestus (Heller) in the laboratory. La Mer, 1968, vol. 6, no. 4, pp. 263–278.

16. Chong S. S. C., Khoo H. W. The abbreviated larval development of the freshwater prawn, Macrobrachium malayanum (Roux, 1934) (Decapoda, Palaemonidae), reared in the laboratory. Crustaceana, 1987, vol. 53, no. 1, pp. 29–42. https://doi.org/10.1163/156854087x00592

17. Shokita S., Takeda M., Sittilert S., Polpakdee T. Abbreviated larval development of a freshwater prawn, Macrobra- chium niphanae, Shokita and Takeda (Decapoda: Palaemonidae), from Thailand. Journal Crustacean Biology, 1991, vol. 1, no. 1, pp. 90–102.

18. Bueno S. L, Rodrigues S. Abbreviated larval development of the freshwater prawn Macrobrachium iheringi (Ortmann,1897) (Decapoda, Palaemonidae), reared in the laboratory. Crustaceana, 1995, vol. 68, no. 6, pp. 665–685. https:// doi.org/10.1163/156854095x01880