How does arowana divide male and female?
characteristic 1: the size of the arowana
in general, the size of the male arowana is longer than that of the female arowana in the same situation. It seems that the males of most biological species are larger than the females.
characteristic 2: the shape of the ventral fin of the arowana
normally, the ventral fin of the male arowana is sharp and long, while that of the female arowana is not very long, and it is not as long as that of the male arowana.
Feature 3: Abdominal shape of Arowana
In mature individuals of Arowana, the abdomen of female Arowana is relatively swollen because of her eggs, which is also a feature that directly distinguishes the male and female of Arowana.
characteristic 4: the head size of the arowana
because the male arowana needs to contain eggs in his mouth, the head size of the male arowana is relatively large.
feature 5: the shape of the gills of the arowana
A beautiful A can be seen in the gills of the female arowana, and the arrow part is shorter than that of the male. The A word of the male arowana is irregular and the arrow part is longer.
The above are the five obvious characteristics of how the arowana distinguishes between male and female, but even so, it is still difficult to distinguish them without a good reference.
Extended information:
Double-bearded bone tongue fish (scientific name: Osteoglossum? Bicirrhosum), also known as arowana, is distributed in the Amazon river basin. It is an important catch in the local area and one of the main ornamental fish, and it is quite popular in Asia because of the demand for geomantic omen.
the body of the arowana is long and flat, and the tail is fan-shaped. The dorsal fin and anal fin are band-shaped and extend backward to the base of the tail stalk.
The lower jaw is more prominent than the upper jaw, with a pair of short and thick whiskers.
Arowana fish has five rows of large scales neatly arranged on its wide body, and it shines with silver light under the light. Each fin reflects bright red or orange luster under light. The body color of young fish is blue; Both dorsal fin and gluteal fin have red and blue edges. The scale edge of Jinlong is golden yellow, and all fins are golden red.
The body color of the red dragon is golden yellow, the scale edge is golden red, and there are crimson patches on the mouth and gill cover, and all the fins are crimson. The body of the silver dragon is silvery white, the body of the black dragon is silvery white and slightly bluish purple, and all the fins are basket black. Arowana can reach 5~1 cm in length.
the silver belt has a very slender and thin body shape. The position of the mouth is above, and the fissure extends to the posterior edge of the eye socket. The lower jaw is more prominent than the upper jaw, and several linear lateral organs are arranged side by side in front. There are a pair of tentacles at the snout. The tentacles of adult fish can be extended to 3-4cm in the wild individuals who swim in the natural environment, but they can only grow to 1-2cm under artificial feeding because their growth is hindered.
The tooth bones of the lower jaw are well developed. The conical teeth arranged like combs between the upper jaw and the lower jaw are very small and sharp, and the intervals between the teeth are very narrow. Not only the anterior maxilla, but also the accessory butterfly bone of the odontoid joint and the tongue-forming bone are well developed, which is developed to bite large crustaceans and beetles? From the Arowana Exhibition.
In addition, the upper and lower jaws pay more attention to the hunting function of catching prey rather than the bite force of their teeth. The gill rakes develop into spines. Gollum's big eyes are close to the front of the palate, and his vision is very good. The kiss is very short. The nostril is located in the front and upper part of both eyes, very close to the snout. Dorsal fin and gluteal fin are very long, and the starting point of gluteal fin is more front than dorsal fin.
The first spinous strip of the extended ventral fin even exceeds the starting point of the gluteal fin. The pectoral fins are well developed. In particular, the long and powerful first thorn strip is a sharp weapon for the silver belt to jump out of the water. This wonderful flying power makes the silver belt win the "jumping fish" (Amazon "water monkey") in South America, which is easy to jump at night, so more protective nets are added. ) laudatory name.
The side of the arowana is covered with five rows of large and beautiful round scales. The lateral line runs from the top of the posterior margin of the posterior branchial lid of the head to the caudal stalk. The body height is about one fifth of the body length. The male fish of five to eight years old, about 9 cm, is much taller than the female fish.
the middle part of the body of the arowana can even be close to two centimeters. Such an attractive appearance like this can't compare with the expensive Asian arowana. Unfortunately, it is hard to find a silver belt with this appearance.
Reference: Baidu Encyclopedia-Arowana.