Where do sea fleas live? - briefly
Sea fleas inhabit shallow marine and brackish waters, attaching to algae, rocks, sand and other substrates in intertidal and near‑shore zones. Certain species also exist as ectoparasites on fish.
Where do sea fleas live? - in detail
Sea fleas, also known as marine amphipods of the family Hyperiidae, inhabit the pelagic zone of oceans worldwide. They are most abundant in temperate and subtropical waters, but populations occur from polar regions to the tropics. Their distribution follows major oceanic currents, which transport them across vast distances.
Typical habitats include:
- Surface to mid‑water columns, generally between 0 and 200 m depth.
- Areas of high plankton productivity, such as upwelling zones off western coasts of continents.
- Open‑ocean gyres where they form part of the zooplankton community.
- Coastal shelves during seasonal blooms, when food availability spikes.
Sea fleas are ectoparasites or commensals on gelatinous zooplankton (jellyfish, salps, ctenophores). They attach to the host’s bell or tentacles, feeding on mucus, tissue, or captured prey. Consequently, their presence is closely linked to the distribution of these gelatinous organisms. In regions where jellyfish dominate, flea concentrations can reach several hundred individuals per cubic meter.
Seasonal patterns affect abundance. In temperate seas, numbers rise in spring and summer, coinciding with phytoplankton blooms that support larger zooplankton populations. Winter months see reduced densities, though some species persist at low levels in colder, deeper waters.
Environmental parameters influencing their habitat include:
- Temperature: optimal range 5–25 °C; extreme cold or heat limits survival.
- Salinity: tolerates typical marine salinity (30–35 ppt); freshwater influx reduces viability.
- Dissolved oxygen: requires well‑oxygenated waters; hypoxic zones are avoided.
Overall, sea fleas occupy the open water column, relying on the availability of gelatinous hosts and favorable physical conditions to maintain their global distribution.