“A HORSE IS A HORSE, OF COURSE,” UNLESS IT IS A SEAHORSE

Seahorses are ray-finned fishes. They weight 7 ounces to 1 pound. The largest ones are up to 35 cm long.  They have a horse-like head, with elongate noses, and curled tails that are prehensile (= they have the ability to hold onto objects). Their bodies are covered with consecutive rings of interlocking bony plates. They also have tubular snouts and a small toothless mouth. They eat by suction. They no have stomach. The color of seashores can be brown to black, but they can have yellowish, reddish purple, or greenish patches. Seahorses have a ravenous appetite. Their eyes can move independently. During reproduction, the males carry the babies.  

Seahorses live one to five years in captivity. They can make good pets, but they have to have the right environment (e.g., their tanks holding at least 40 gallons of seawater). 

There are about living known genera and 225 species of seahorses. Their classification is as follows:

Phylum Chordata

Class Actinopterygii

Order Syngnathiformes

Family Syngathidae 

Genus Hippocampus (the word means horse). There are about 50 genera, and the most common one is Hippocampus. 

Seahorses branched most likely from “pipe fish," which have long and narrow bodies.” 

The earliest known fossil record of seahorses is middle Miocene (13 million years ago), in Slovenia, Europe (Zalohar et al., 2009). The skeletons are well preserved and look just like a modern seashore. There is no doubt that they are seashorses.

Three views (left, right, and front) of the skeleton of a typical Hippocampus seashorse, length 55mm (2.5 inches), width 10 mm (1.25 inches), and thickness 6 mm (1/8 inch wide). The skin of this specimen is not preserved, therefore, identification as to species was not possible.

The “weedy seahorse” or “leafy sea dragon.” (image modified from a picture in the “Eyewitness Books” Fish (p. 23). Specimens like the one illustrated here can be up to 12 inches (30 cm) in length.

Seashorses live mainly in warm waters in the Indian Ocean, Pacific Ocean (especially southern Australia) and New Zealand, and also in the Caribbean Sea. They like to live in areas where sea weeds are abundant, thereby allowing them to hide from predators.

REFERENCES CITED

Eyewitness Books (Fish), 1990. Alfred A. Knopf, New York, 64 pp.

Zalohar et al. 2009. Two new species of seahorses (Syngnathidae, Hippocampus) from the middle Miocene Tunjice Hills, Slovenia. Annales de Paleontolgie 95:21-26. 

Wikipedia. 2024.