Now that the excitement of summer camp is over, we think it's time to reinstate Fun Fish Fridays. This week we are going to learn about a very unique fish that doesn’t look much like its cousins – the seahorse. That’s right, the seahorse is actually a highly modified fish in the class Actinopterygii, or ray-finned fishes. The seahorse belongs to the genus Hippocampus, which literally translates from Ancient Greek to “horse” (hippos) and “sea monster” (kampos). This horse-like fish is prevalent in the waters around Sanibel and Captiva; we actually have 3 species that inhabit the region: the dwarf seahorse, lined seahorse, and longsnout seahorse.
The dwarf seahorse (Hippocampus zosterae) is common in the seagrass beds in Florida and throughout the Caribbean.
Let’s start with the basics. Seahorses have the same basic fins as most other fish: a dorsal fin and paired pectoral fins. However, instead of a caudal fin (tail fin) the seahorse has an elongated, prehensile tail that it uses for stabilizing itself in the ocean currents. It wraps its tail around seagrass or coral and hangs on tight, helping it save energy for other uses. We've even observed a seahorse catching a ride on an arrow crab's back!
Notice the curved prehensile tail of this lined seahorse (Hippocampus erectus). This species can grow up to be almost 6 inches!
Like many other fish, seahorses are voracious, carnivorous predators, but because they have no true stomachs, they have to constantly eat to meet their energy requirements. Some seahorses may consume up to 3,000 brine shrimp in one day! To chow down on so many crustaceans, they have a specialized mouth. Their jaw is fused, creating a straw-like shape that enables them to ambush and quickly slurp up their prey.
One of the seahorse's favorite meals, the brine shrimp, is an aquatic crustacean that is only slightly related to true shrimp.
There is one aspect of a seahorse’s life that differs quite drastically from other fish. When seahorses are ready to reproduce, the male and female engage in an elegant courtship dance to seal their bond. Soon after, the female deposits her eggs into the male’s brood pouch where they are fertilized and incubated for up to 25 days. The male will then give birth to hundreds or thousands (depending on the species) of baby seahorses that are miniature copies of the adults. Scientists aren’t exactly sure of the biological advantages of Mr. Mom, but one theory is that it could allow the female to begin producing eggs as soon as she delivers her last batch to the male. Check out the courtship dance of one of the seahorse's closest relatives, the Weedy Seadragon:
Because seahorses are so unique and sensitive to environmental changes, scientists are studying them to better understand how to improve the overall health of our oceans on a global level - find out more here: http://seahorse.fisheries.ubc.ca/why-seahorses