Factors influencing the distribution of Mysids (Crustacea: Mysida) in the Negombo lagoon, Sri Lanka

Abstract

Mysids are minute crustaceans that occur in large numbers in estuarine waters. Their significant role as a main food source for fish populations is becoming apparent. There is currently, limited information on mysids in Sri Lankan estuarine waters. The present study investigated the distribution of mysids in the Negombo Lagoon from June 2012 to May 2013 at 18 randomly selected-sites along the lagoon. Surveys were conducted along the boundary of the lagoon, during day time, using a dip net (opening of 25 × 20 cm 2) with 500 µm mesh size. The spatial distribution survey recorded 11 mysid habitats. Mesopodopsis zeylanica, and a potentially new Siriella sp. were identified, M. zeylanica being the most abundant species. Survey of temporal variation in mysid abundance was also carried out at two sites for a sixmonth period. Mysid species did not show any temporal variation and the distribution and abundance was not affected by any single environmental factor. The spatial distribution of mysids along the lagoon boundary was found to depend mainly on the estuarine boundary conditions. Mangrove vegetation along the estuarine boundary was found to be favorable for mysids while concrete boundaries and accumulation of garbage along boundaries were found to be unsuitable.

Evaluation of Potential Factors affecting the Distribution of Mysids (Crustacea: Mysidacea) in Puttalam Lagoon, Sri Lanka

“…The previous studies in the Bolgoda and Negombo lagoons (Punchihewa et al, 2017;Punchihewa, and Krishnarajah, 2019) revealed that mysids were absent from the areas where boundary vegetation consisted of water hyacinth, garbage dumping areas and edges constructed with concrete. Therefore, this study also demanded good condition of the estuarine boundary which is important for mysids occurrence.…”

“…The mysids in the Auckland region showed that the salinity ranges for which each three mysid species distributed, (Tenagomysis chiltoni 0-18 ppt, Tenagomysi novaezealandiae, 26 ppt and Gastrosacus australis 1.5-12.6 ppt) were different (Punchihewa and Krishnarajah, 2013a). According to previous studies in Sri Lanka (Punchihewa et al, 2017;Punchihewa and Krishnarajah, 2019), estuarine boundaries with natural vegetation are the most suitable mysid habitats than the boundaries with man-made concrete edges. The present study also assess whether the boundary vegetation depends on the distribution mysid in the Puttalam lagoon.…”

“…This species is also found in a tropical estuary, the Cochin backwater in India (Biju and Panampunnayil, 2010). Mesopodopsis zeylanica and a new species, Sirella srilankensis were recorded from Negombo lagoon (Punchihewa and Krishnarajah, 2019). Thus, it is important to carry out a further survey of mysid species in estuarine areas to gather up to date information on the distribution and abundance of mysids in Sri Lanka.…”

Mangroves As Coastal Bio-Shield: A Review of Mangroves Performance in Wave Attenuation

“…In recent decades, researchers have alleged the benefits of mangroves trees in 1) maintaining the natural biodiversity of the coast [8], 2) providing vital nursery grounds for juvenile fish and crustaceans [1,9], 3) providing coastal protection against flooding and erosion directly by dissipating energy [10], and 4) providing substantial carbon sequestration for regulating services [11]. In addition, the mangrove ecosystem also plays a consequent role in the provision of food and shelters to diverse marine and terrestrial organisms [12].…”