Scientistic popularization and “best friend” are concepts that don’t seem very compatible. First, although the language is accessible to many people, it is not a universally understood task. Second, scientific data is essential for this task. The notion of “good lover” is, however, one of the most subjective concepts.
It is actually fascinating to see the diversity of practices, requirements, and procedures that our peers consider stimulants to maximize performance in mating rituals. Love strategies are governed by the brilliant maxim “there are people who pa’ to”.
This is why I will be focusing on objective, testable arguments. But, it is important to understand how sharks do this.
Fertilization is done externally in most aquatic animals. This is easy to understand when we consider that spermatozoa, which are mobile cells that can swim, fertilize aquatic animals. They are able to propel themselves in fluid and dense media like water by possessing a terminal scourge (which they whip like Indiana Jones).
This idea allows us to imagine that the oceans, seas, and rivers are essentially a soup. The chickpeas are the eggs released by females of different species, and the noodles (micronoodles) are the spermatozoa from their corresponding men.
Each sheep will choose to mate with its mate due to the chemotaxis and affinity of the membrane proteins in both types of sex cell. This means that the spermatozoa from a particular species fertilize the ovum of that species without any molecular attraction to the ovules from multiple other species.
This method of fertilization is used by most fish taxa. The exception to this rule is the chondrichthyans. This group includes cartilaginous fish such as sharks.
Sharks are cooler than everyone. Sharks can be fertilized internally.
Internal fertilization is an evolutionary transcendental invention. No, I am not talking about how interesting or funny the physical encounter required for it to occur, as some readers might think. Because it is extremely profitable and energetically very lucrative, it is a first-line evolutionary conquest.
Freely releasing gametes into the environment can be dangerous and reduce the chance of fertilization. We must remember that gametes are, as any other biological material, a food source for animals.
Additionally, it is possible that embryonic development proceeds as planned, even if the impossible process of karyogamy has been completed and the zygote formed. This is an extremely unlikely fact.
How can you avoid this horrible fate?
It’s all about the numbers. Both males and females create a lot of gametes, hoping that only a small percentage of them will succeed. Rest of the material will be used for reproduction, but it won’t go to waste.
It is clear that reproductive performance would be improved if there were fewer gametic losses. If you prefer a direct language, the sperm could be accessed by the ovules within a safe, secure, and calm little nest.
Well, oh, wonder! The copulatory appendages were created. There are only two channels that allow for physical contact between gametes. Direct meeting bridges are possible without the presence of predators and without thermal oscillations.
Natural selection favoured everything that was associated with an improvement in the fertility of the reproductive process, which led to an increase in efficiency. This evolutionary line was taken up by sharks, and they succeeded!
Pterygopods, or claspers, are the copulatory appendages that male elasmobranchs use to mate (basically sharks and sunrays). They are incredible.
This qualifier can be used indefinitely. These organs have remarkable characteristics such as the following:
1.- We will start with size. This is an objective, quantifiable character that tends obsessively follows the staff. Their wingspan can account for a large portion of their body’s length when they reach sexual maturity. Leucoraja Erinacea is actually about a third of its total length (and nearly half if you remove the tail segment). Size matters here, obviously.
2.- They don’t need any stimulation to achieve rigidity that allows for efficient copulation. This is because they have a bone system. It is possible to hear it. Pterygopods don’t need to be watched: the factory guarantees rigidity. The basipterygium is a terminal cartilage in the pelvic fins. It is extremely long and enters the clasper giving it rigidity. This rigidity is also maintained throughout your life because it is caused internally by a skeletal nature.
3.- This cartilage is found in many species. It gives rise to a skeletal part (the rhipidion), which flattens and broadens to maximize the dispersion of the fertilized sperm within the female’s genital canals.
4.- The last piece of information is reserved for the end. The copulatory organ of sharks is not a copulatory one. They have two! Remember, I mentioned previously that claspers are modified versions of the terminal ends of the pelvic fins. These are arranged on either side of the anus in pairs. This results in two pterygopods.
The pterygopods (or pterygopods) of sharks are enormous, have an inbuilt sprayer, are not dependent on Viagra, and are not subject to constant review. There is always another one in case of damage to any one. Let’s see how male humans improve that!
This article was published in “The Conversation”.
