Male vs Female Crayfish
Crayfish are prehistoric animals, as their earliest fossils found from Australia could date back to 115 million years from today, but the other fossil records are only 30 million years old. People have been using crayfish as bait for fishing. They are a popular food source across the world including China, Australia, Spain, United States, and many other countries. They have been used as pets in many aquaria. These animals have been classified under three taxonomic families and two of which are distributed in the northern hemisphere with the highest diversity in the North America (more than 330 species in nine genera). There are seven species is two genera in Europe while the Japanese species is endemic to the region. The Madagascan species and Australian species are endemic to those regions, and it would be important to know that there are more than 100 species distributed in Australia. It would be interesting to notice that there is a pronounced difference between families of Southern and Northern hemisphere crawdads, which is the absence of the first pair of pleopods in the Southern hemisphere family.
Crayfish are also known as crawfish or crawdads depending on the location. They are a group of crustaceans; they also have hard shells and claws to protect themselves, yet there are crayfish characteristics to make them unique among all crustaceans. However, the males and females of crayfish differ from each other in many ways such as body size, genitals, and the legs or swimmerets.
Among most of the crayfish species, males have the larger and most conspicuous body among females. The most obvious feature of the males is the male reproductive system, which opens through a pair of small genital openings on the abdomen. There are three lobes in the internal testis to produce spermatozoa. There are two tubules of the vas deference, and it leads to the exterior at the genital openings. It would be important to notice two pairs of long and tubular legs, usually the first two pairs. However, those long and tubular legs could be prominently seen in sexually mature crayfish males. Their abdomen is usually small, and the legs (also known as swimmerets) are not very well developed, as the males would not have carry eggs with them.
Female crayfish are generally smaller than the males, but the other features appear to be more conspicuous than males. Being females, the presence of female reproductive system is obvious. The reproductive system is mainly composed of an ovary with three lobes, and it leads to the exterior through the oviduct. The external openings are small and locate slightly away from each other. After the copulation with a male, the swimmerets of the female on the ventral side of the abdomen become heavy with clutches of eggs. Usually, a female crayfish is capable of carrying about 200 eggs at one, but there are recorded instances with females carrying more than 800 eggs at once. The ability of females to carry a large number of eggs is facilitated with a large abdomen and well-developed swimmerets.
What is the difference between Male and Female Crayfish?
• Males are larger and longer than females are.
• Males have more conspicuous claws than females do.
• The first two pairs of legs in mature males are longer than in females.
• The genital openings are located closer in males than in females.
• Abdomen is larger in females than in males.
• Females have well-developed swimmerets than males do.