Although the seahorse and the pipefish can be found within the same family, the Syngnathidae family, they represent different genus’ within the animal kingdom. Seahorses and Pipefish are in the same Syngnathidae family, however the two species are separated into further genus. The pipefish are considered Syngnathinae and a seahorse is considered to be part of the Hippocampinae genus. With this being said, they have some differing attributes to their genetics, as well as some similarities being closely related. For instance, a major similarity between the two species is the fact that the male specimen is the one that actually becomes pregnant and carries the child. Which is backwards from most animals and even humans, as the female specimen is usually the one with the fetus. This phenomenon is something that has driven experiments throughout history to see why these two specimens are basically the reverse of every other animal in the animal kingdom. We will be uncovering the similarities and differences of the male reproductive system that are seen within the Syngnathidae family, including the seahorse and the pipefish.
Seahorses are very interesting animals, considering the fact that they carry many different features when compared to other animals. They are known to be the only animal species in which the male bears the unborn offspring. Seahorses are considered to be fish, but they lack a stomach and teeth. Since no stomach is present, they have to be eating constantly because of the fast digestion that occurs and with no teeth in their mouth, seahorses swallow their food as a whole. Studying the structures of seahorses is made a little easier with over thirty-two different species within the Syngnathidae family. These thirty-two species makes a small portion of the overall genus (Jones, 2001). Seahorses do not have a comparable large class of species, and due to this Seahorses are rapidly moving toward becoming an endangered species, due to pollution. According to Hall, what allows the seahorse to be identified within the genus that it is, is the fact that it has scales, as well as bony plates for protection of the body. They have a skeleton consisting of bony plates that are used not only to protect them, but also the egg when eventually they become pregnant. Unfortunately, the populations of seahorses are beginning to decrease because of the influence human’s play on their habitats. Pollution is destroying the homes where these seahorses find a sufficient amount of sea grass beds. Seahorses are not known to live very long lives. Therefore, they must replace rather quickly to keep their population alive. The typical lifespan of a seahorse is seen to be around one to five years old, depending on the location in which the specimen lives (Foster, et. al 2004). Another reason for their short-lived life is due to the waters they live in. Seahorses do not swim well; they usually die in oceans with high currents due to exhaustion.
Still discussing the Syngnathidae family, the pipefish contain over two hundred different species, which makes up most of the species that are associated within the family. The pipefish is sometimes confused with a seahorse due to some similarities between the two. The pipefish get their name from their snout, which is long and thin, similar to a pipe. This snout restricts them from eating large prey; therefore, pipefish usually feed on a specialized vegetation diet. Most pipefish like to prey on shrimp and planktons. On the other hand, due to the fact that pipefish are so small, they are typically a good prey for bigger animals. Typically, pipefish’s predators are birds, such as puffins, crabs, and whales. However, pipefish use their bodily structure as a protective device against predators, as they can blend in with reeds, sea grass, and even kelp (Garcia et. al, 2005). Most pipefish can be found living in habitats where they are submerged in water that is 1 to 1.2 meters deep (Malavasi et. al, 2007). Compared to a seahorse, pipefish also tend to have a short-lived life, ranging from about one to two years, depending on the habitat where the species is located (Franzoi et. al, 1993). Most pipefish can be found in warm, shallow waters, usually in the Atlantic and Pacific oceans.
The most interesting part of the seahorse when compared to every other living animal is that the male seahorses are the ones who carry the offspring. Clearly, this change of biology also changes the workup and anatomy of both male and female species. The male seahorse incubates the eggs within a pouch on the external pocket in the stomach until the eggs are ready to hatch (Wittington et. al, 2001). Seahorses use various parts of their body to initiate mating with another seahorses. The main parts that can be classified as the reproductive system for seahorses include, tail, mesenteries, anal fin, and the male brood pouch, only found in males. During mating, the tail is used to ensure closeness and prevent separation. The mesenteries, found along the front of the kidneys, are what initiate the reproductive organs of the seahorses. This initiation includes the testes of males and the ovaries of females (Tang, 1970). After contact with the female, the anal fin is where the “connection” occurs. The anal fin, located just above the brood pouch, allows the sperm that was released to travel towards the mature eggs from the female and enter the male’s brood pouch. In other words, the male pouch opens during mating to allow the partner seahorse to deposit the mature eggs. The male brood pouch provides nutrients and oxygen to the newly placed egg and protects the egg from any harm. When comparing female to male seahorses the only physical difference is that the females tend to have a more rough and angular abdominal area, whereas the males are smooth and contain the reproductive pouch.
Female and male pipefish have to endure certain characteristics in order to mate with one another. Both male and female pipefish undergo a few rituals for the mating to begin. For example, they both must be traveling at the same speed and have the same movements in order for the female to pass the eggs to the male. The males, similar to seahorses, have a spongy area around their tail that is used to carry the eggs. However, depending on what type of species of pipefish is being studied depends where the location of the egg being developed will be found (Jones, 2001). Some pipefish are known to incubate the eggs within their mouth so that nutrients are directly being absorbed by the future offspring. Other species of pipefish will incubate the egg in the male brood pouch. Incubation typically last approximately two weeks. Study shows that the more ‘attractive’ mothers, attractive being defined as bigger in size, tend to have offspring who were more likely to hatch The strange male brooding structure within the pipefish is what allowed evolution to create the ability for the male specimen to incubate the eggs (Stolting et. al, 2007). Interesting enough, female pipefish are known for producing more eggs than a male can take care of in their pouch. Studies show that reproduction in pipefish have a peak in Florida in late spring and early summer, mostly in the waters of the Gulf of Mexico.
As unique as seahorses and pipefish are, they share many similarities regarding their reproductive system. In both species, the females are responsible for depositing their eggs into the male’s external or internal pouch. Due to the fact that the male then incubates the eggs, the male is also in charge of gathering nourishments for the eggs. Also, both specimens produce the eggs within the short timeframe of shortly less than to right around a full calendar month (Wilson, 2003). Both species can be further separated into four groups depending on the degree the complexity of the pouch used to store the eggs in males. Once the egg has left the female, it is inserted onto a spongy mass inside the brood pouch of the male, covered in skin folds. The skin folds of the tail never meet up to close, so the egg is not completely covered and therefore not completely protected (Kornienko, 1999). This shows that the eggs are not completely protected during development; instead only contain a spongy matrix that is formed by skin folds on the pouch. The interesting part of the fertilization that takes place, is that when the female goes about depositing the eggs, the men facilitate the reproduction by dousing the eggs in sperm (Whittington et. al, 2001). The actual occurrence of depositing the egg into the brood pouch takes no more than a second to complete.
Even though these two species are very related in terms of reproductive measures, they differ in the ways that they go about living life. This also allows for the extension of life patterns, as well as adaptation along the lineage of further reproduction. With this being said, the seahorse does inhibit different patterns for reproduction than the pipefish, having the pouch on the external side of the abdomen. Whereas the pipefish is known to incubate the offspring within the tail, or even the mouth. This is what allows the differences between the two species to be investigated and discovered even though they are both a part of the Syngnathidae family. Another difference that allows researchers to find out why the reproduction does complete the sex reversal is seen through the separate genuses that the two species represent within the animal kingdom. Studies are still being conducted to understand why evolution changed and resulted in the males of both species to become pregnant, as opposed to the norm.