#Breeding season 6.6.1 torrent skin#
By contrast, canal neuromasts occur under the skin within fluid-filled canals that contact the surrounding water via small pores.
Superficial neuromasts sit on the surface of the skin and are in direct contact with external hydrodynamic flow fields near the body of the animal, allowing them to detect water velocity. There are two general types of neuromasts with different receptive capabilities. All of the hair cells in a neuromast extend their cilia into a gelatinous cupula that projects into the surrounding water and is mechanically coupled to local water motion. The lateral line system conveys information about local water displacement over the body surface via clusters of hair cells called neuromasts, which are organized in many anatomically distinct lines. The mechanoreceptive lateral line is a sensory system that is unique to aquatic vertebrates and is used to detect water motion in aquatic environments ( Dijkgraaf, 1963 Bleckmann, 1993). Our data provide the first demonstration that the lateral line sensory system can vary significantly between individuals and among populations within a single species, and suggest that this sensory system may experience different selection regimes in alternative habitats. In two independent lakes, benthic sticklebacks had more trunk neuromasts than sympatric limnetic sticklebacks, providing evidence for parallel evolution of the lateral line system.
Stream residents had more neuromasts than marine sticklebacks living downstream in the same watershed. In pairwise comparisons between threespine sticklebacks adapted to divergent habitats, we found significant differences in neuromast number. Although the arrangement of lines of superficial neuromasts on the body was largely the same in all populations, the number of neuromasts within these lines varied across individuals, populations and habitats. We found that the threespine stickleback has a reduced lateral line canal system, completely lacking canal neuromasts. We sampled 16 threespine stickleback populations from marine, stream and lake (including benthic and limnetic) habitats and examined the distribution, type and number of neuromasts on different regions of the body. aculeatus species complex might show variation in the morphology of the lateral line sensory system. Threespine sticklebacks ( Gasterosteus aculeatus) occupy a diverse range of aquatic habitats we therefore hypothesized that populations within the G. Variation in lateral line morphology may allow fish in different habitats to differentially sense and respond to salient cues. The lateral line is a mechanoreceptive sensory system that allows fish to sense objects and motion in their local environment.
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