The term razorfish may refer to any of the five small species in the Centriscidae family. These fish, also known as shrimpfish, are divided into three genera: the Aeoliscus, Centriscus, and Centriscops, though some are also occasionally placed into the Macroramphosinae subfamily. Razorfish are usually small, slim and transparent, with blade-like bellies and long snouts. Most varieties may be found in the shallow depths of the Indo-Pacific, while others occur in the deeper waters of southern oceans.
Razorfish, which are closely related to the seahorse, are marine fish that generally live in shallow areas of the Indian and Pacific oceans, but may also reside in deeper waters. Most groups of razorfish are nearly transparent in appearance, but sport a thin, colorful stripe along their sides. They have flattened sides, and a sharp-edged appearance to their underbellies. The fish are also covered in a see-through, fused armor plate that ends in a long dorsal fin spine.
One of the better-known species is called Aeoliscus strigatus, or the striped shrimpfish. This fish can vary in color depending upon habitat, but is generally light silver with either a deep red or green-yellow stripe along the top and bottom of their bodies. The Centriscops humerosus, or banded bellowfish, is another well-known species. This group differs from the striped shrimpfish in length and the unusual hump that forms just behind the head. It also bears light orange or dusky yellow stripes.
Behaviorally, most species of razorfish act in a similar manner. One of their most recognizable habits is to swim head down in a synchronized fashion. They also tend to hide in the spines of sea urchins as a means of self-preservation and food gathering. Larger fish are wary of being stung by the sea urchin, so when threatened, razorfish will generally hide among the spines to protect themselves. Razorfish also hide within the spines to cloak themselves from their own potential prey, darting out only when tiny invertebrates are within their reach.
Although the razorfish thrives best in an ocean setting, it can also be kept in a home aquarium. These fish can be difficult to keep, but can survive in an aquarium with algae, live rock, and plenty of places to hide. They may be placed with similar species such as pipefish, but will not fare well with more aggressive fish like wrasses.