A review of the order mysida in marine ecosystems: What we know what is yet to be known

Brain morphology in the peracarid crustacean Neomysis integer (Leach, 1814) with an emphasis on sexual dimorphism of the olfactory pathway

Our current understanding of brain organization in malacostracan crustaceans is strongly biased towards representatives of the Decapoda ("ten legged" crustaceans) such as crayfish, crabs, clawed lobsters and spiny lobsters. However, to understand aspects of brain evolution in crustaceans, a broader taxonomic sampling is essential. The peracarid crustaceans are a species-rich group that embraces representatives of, e.g. the Isopoda, Amphipoda and Mysida ("opossum shrimps"), taxa whose neuroanatomy has not been carefully examined. The current study sets out to analyze brain morphology of the mysid Neomysis integer (Leach, 1814; Peracarida, Mysida) using immunohistochemistry against the presynaptic protein synapsin and the neuropeptides RFamide, SIFamide and allatostatin combined with three-dimensional reconstruction of elements of the central olfactory pathway. Furthermore, we studied the inventory of sensilla on the first pair of antennae using cuticular autofluorescence. Anterograde filling with neuronal tracers allowed visualisation the central projections of the sensilla on the first pair of antennae. This species is known to display a sexual dimorphism in both the peripheral and central olfactory pathway. We focussed our analysis on this aspect because in contrast to Hexapoda, reports on a sexual dimorphism of the olfactory system are extremely rare in malacostracan crustaceans. We provide a detailed description of the sensilla associated with a male-specific structure on the pair of first antenna the "lobus masculinus". Furthermore, we analyzed the projection patterns of theses sensilla into the "male-specific neuropil" in the deutocerebrum and critically discuss our results in comparison to examples of sexual dimorphism in the chemosensory pathways in other malacostracan crustaceans and hexapods.

Adaptation and potential culture of wild Amphipods and Mysids as potential live feed in aquaculture: a review

Live foods such as phytoplankton and zooplankton are essential food sources in aquaculture. Due to their small size, they are suitable for newly hatched larvae. Artemia and rotifer are commonly used live feeds in aquaculture; each feed has a limited dietary value, which is unsuitable for all cultured species. Whereas, copepod and cladocerans species exhibit favorable characteristics that make them viable candidates as sources of essential nutrients for hatchery operations. Due to their jerking movements, it stimulates the feeding response of fish larvae, and their various sizes make them suitable for any fish and crustacean. Even though Artemia is the best live feed due to its proficient nutritional quality, the cost is very expensive, which is about half of the production cost. A recent study suggests the use of amphipods and mysids as alternative live feeds in aquaculture. High nutritional value is present in amphipods and mysids, especially proteins, lipids, and essential fatty acids that are required by fish larvae during early development. Amphipods and mysids are considered abundant in the aquatic ecosystem and have been used by researchers in water toxicity studies. However, the culture of amphipods and mysids has been poorly studied. There is only a small-scale culture under laboratory conditions for scientific research that has been performed. Thus, further research is required to find a way to improve the mass culture of amphipods and mysids that can benefit the aquaculture industry. This review article is intended to provide the available information on amphipods and mysids, including reproductive biology, culture method, nutritional value, feed enhancement, and the importance of them as potential live feed in aquaculture. This article is useful as a guideline for researchers, hatchery operators, and farmers.