Streptocephalus sirindhornae

Streptocephalus sirindhornae is a species of crustacean in the family Streptocephalidae; a genus of freshwater dwelling shrimp belonging to the Anostraca order of Branchiopoda . It is endemic to Thailand, and it was named after Princess Sirindhorn.^[1]

Streptocephalus sirindhornae
Eggs of Streptocephalus sirindhornae, 0.1 - 0.3 mm in size
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Branchiopoda
Order:	Anostraca
Family:	Streptocephalidae
Genus:	Streptocephalus
Species:	S. sirindhornae
Binomial name
Streptocephalus sirindhornae Sanoamuang et al., 2000

Habitat

Streptocephalus sirindhornae inhabit inland freshwater temporary waters, known as vernal pools.

Reproduction

Streptocephalus sirindhornae displays sexual dimorphism, featuring both male and female sexes. The species reproduces sexually, with the male shrimp fertilising the eggs of the female. Once fully formed, the eggs are released by the female shrimp.

The male shrimp features an additional enlarged frontal appendage used to grasp the female during mating.

Furthermore, the female shrimp has a brood pouch attached to the base of the tail and last set of swimming appendages, which is used to hold the eggs (cysts) before and during fertilization, as well as throughout egg development. Once substantially developed, the eggs are then birthed from the brood pouch.

Behaviour

Like other fairy shrimp, S. sirnindhornae share the universal ability to enter diapause, a state of biological dormancy where growth and metabolism are arrested, as an egg (commonly called a cyst). This trait assists in both species dispersal and in overcoming adverse environmental conditions that threaten biological continuity. Once dormant, these cysts can withstand conditions as harsh and diverse as droughts, frosts, hypersaline conditions, complete desiccation, exposure to UV radiation and the vacuum of space.^[2]

References

1. Sanoamuang, La-orsri; Murugan, Gopal; Weekers, Peter H. H.; Dumont, Henri J. (2000). "Streptocephalus sirindhornae, New Species of Freshwater Fairy Shrimp (Anostraca) from Thailand". Journal of Crustacean Biology. 20 (3): 559–565. doi:10.1163/20021975-99990073. JSTOR 1549397.
2. Hairston, Nelson G.; Cáceres, Carla E. (1996-03-01). "Distribution of crustacean diapause: micro- and macroevolutionary pattern and process". Hydrobiologia. 320 (1–3): 27–44. doi:10.1007/BF00016802. ISSN 0018-8158.