#Trout # Trout is a group of small carp fish, about 40 species in the world, mainly distributed in East Asia, there are more than 20 species in China, and only 1 species in Europe. It lives in freshwater lakes and swamps, is small and has a beautiful appearance: its silver-gray body is inlaid with orange and blue-green markings, bright and brilliant.
Pomfret
#River mussel #River mussel is a class of molluscs phylum eucalyptus mussels of the family Eucalyptus mussels, living in freshwater lakes, ponds, rivers and other water bottoms, half buried in sediment.
River mussels
Trout have a very special reproductive habit: during reproduction, the fallopian tubes of females elongate into tubes and become a long spawning tube. When the trout lays eggs, it first looks for the river mussel, and with the help of this slender tube, inserts it into the gill water pipe of the river mussel, and lays the eggs in the gill water pipe or in the outer mantle cavity. After the female has laid eggs, the male immediately fertilizes her. The fertilized eggs hatch and develop in the mussel body, relying on the breathing water of the mussel to make the fertilized egg get sufficient oxygen, and after a month, the baby fish emerge from the river mussel.
Trout-river mussels are co-evolving
While adopting the descendants of the salmon, the river mussel also entrusted its children to the scorpionfish to raise. The spawning period of the mussel is exactly the same as that of the sturgeon, usually the mussel lays the juvenile shell in the water, so when the mussel lays the eggs in the mussel, the juvenile mussel attaches to the adult fish of the sturgeon at this time, and completes its initial development on the body of the trout. When the sturgeon swims past the river mussel, because the vibration of the water stimulates the mussel, it discharges a large number of hook larvae from the water hole and attaches the hook to the gills or fins of the fish body. Stimulated by hook larvae, the fish body quickly forms a quilt and wraps the larvae. So the larva begins its parasitic life until it can earn an independent living.
Different species of trout fish will choose different species of river mussels to spawn, and different river mussels will also choose different trout fish to parasitize, and the host selection is more specific, forming complex interrelationships and carrying out fish-mussel co-evolution.