Characteristic sexual differences in mollies

Many aquarium enthusiasts choose mollies because of their vivid colors and lively habits. In order to maintain a balanced tank environment or to breed mollies, one must understand the differences between male and female mollies.

A few distinguishing characteristics allow us to observe sexual dimorphism in mollies, or the physical differences between the sexes. It is typically easier to distinguish between males and females due to these differences in size, coloration, and fin shapes.

Aquarists can make sure their mollies are happy and healthy by identifying these traits, regardless of whether their goal is to breed the animals or simply observe their lively interactions in the aquarium.

The main differences between a male and a female

Differentiating between a male and female moly is simple. There is a noticeable sexual dimorphism in these fish. It is sufficient to observe the species’ representatives because they vary not only in terms of size but also in terms of behavior, degree of activity, and color.

Size

The sex of the fish is indicated by a number of size criteria. They are listed in the following order:

  1. Females are larger in size. Female black mollies (Mollienesia sphenops) grow up to 13 cm in length, have a fairly dense abdomen. The length of males is 8 cm, larger specimens are very rare.
  2. Sail molly (Mollienesia velifera) is an exception to the rule. Sail males grow larger than females. Males have a fin on their back. Its size is about 5 cm and its shape is similar to a sail. Females have a smaller dorsal fin and a less expressive shape.

The male’s ability to procreate increases with his size. His children are in better health.

Sexual characteristics

Adjacent to the unpaired caudal fin on the abdomen of mollies is an anal fin. Its shape is more rounded and its range of motion is restricted in females (it can only fold and then straighten out). It has a triangle-like form.

The anal fin of males is folded into a small tube. This is the gonopodium, which is home to the hook and seminal fluid groove. During fertilization, the male attaches himself to the female using a device.

The anal fin moves freely and actively in different directions during courtship with the female, but it is always pressed to the belly in its normal state. It is very noticeable at this time.

Females are ready to have babies when they are 6–8 months old. Males reach sexual maturity later, usually between the ages of 8 and 12 months.

Color and activity (behavior)

Males are distinguished by their large fins and comparatively bright, multicolored coloration. Males appear more attractive than females.

They behave in a more active manner than females. They do not fear the other fish in the aquarium and move swiftly about it.

When they are with other women in small groups, they feel much better. They are more engaged and active in this instance. They behave more restrainedly when they are with men.

Participation in the reproduction process

The female molly’s eggs are all covered in sperm after the male fertilizes them. While the remainder stay inside the female until the next spawning occurs, some of them develop into fry right away.

Pregnant female moles’ abdomens enlarge significantly. Its lower portion has a dark patch. The females’ activity drastically drops during this time; they become sluggish and somewhat listless. A typical pregnancy lasts 35 to 45 days. They take refuge in the algae during this period.

The female needs to be watched after spawning is finished. She still has some fertilized eggs in her. It is highly likely that she will bring fries again in about 30 days.

Is it possible to find out the sex of the fry?

Small mollies will always straighten their anal fins right after birth, regardless of sex. To be precise, it is impossible to tell a female from a male. Fry are translucent, about 6 mm in size. They lie on the aquarium’s bottom for a while after birth instead of swimming.

The entire younger generation shares the same physical characteristics as women. They exhibit no virtuous sexual traits. The sex of the fish can be ascertained roughly by the end of the first month and up until the start of the third.

Characteristic Male Mollies Female Mollies
Body Size Smaller and slimmer Larger and rounder
Fin Shape Longer, pointed anal fin (gonopodium) Shorter, fan-shaped anal fin
Coloration Often more vibrant and colorful Usually less intense in color
Behavior More active and territorial Generally calmer

Gaining an understanding of the sexual differences in mollies can enhance your enjoyment as an aquarist. Understanding the physical characteristics that set males and females apart will help you control breeding and keep a healthy tank environment.

Knowing these differences is crucial whether your goal is to breed mollies or just maintain a balanced aquarium. You’ll be able to distinguish between them with ease with some practice, so your mollies will flourish under your care.

Physical characteristics are an easy way to identify male and female mollies; males are usually rounder, duller in color, and have a pointed anal fin, while females are more colorful and slimmer.

Video on the topic

Mollies compatibility, maintenance, reproduction

Aquarium fish mollies. Features. Care.

5 tips on how to properly keep mollies #Shorts

What part of aquarium maintenance do you consider the most difficult?
Share to friends
Olga Vishnevskaya

Biologist by education, aquarist by vocation. Specialization — breeding and care of freshwater aquarium plants. Since childhood I have been fond of aquariums, constantly experimenting with creating biotopes and selecting flora for various types of aquariums. I am sure that green aquariums can transform any interior and improve the quality of life.

Rate author
InfoProekt24.com
Add a comment