The Island of Cozumel, a popular dive destination that is located just off the eastern edge of Mexico’s Yucatan Peninsula, has many unique and beautiful reef fishes. No other reef fish is so closely identified with Cozumel diving than the Cozumel Splendid Toadfish. This fish is given many other common names, such as the Cozumel Catfish or the Cozumel Toadfish. The Splendid Toadfish, Sanopus splendidus, is a colorful species of toadfish “almost” entirely endemic to the shallow waters around the island of Cozumel. It is not seen anywhere else in the Caribbean, except for infrequent encounters on a few near shore reefs of the Yucatan peninsula near Playa Del Carmen and on a shallow reef in Belize.
With vibrant, bright yellow fins and distinctive patterning, the splendid toadfish is a striking exception to the typical drab coloration exhibited by most members of the toadfish family. This very distinctive fish has a wide compressed head with whisker like appendages called barbels growing from its lower jaw. It has horizontal striping and some mottling, usually with charcoal gray or brownish gray lines over white, and a bright yellow border on all of its primary fins.
This species has a total of eight fins; two dorsal fins, two pectoral fins, two pelvic fins, a caudal fin and an anal fin. The two large rounded pectoral fins, which resemble ears, can be found protruding from either side of its flattened head. These very prominent fins are charcoal in color, lined with a wide yellow crescent. The midline of the upper body displays a long flowing yellow dorsal fin. There are two smaller pointed solid yellow pelvic fins positioned right in front of the pectoral fins, on the underside of the fish. When observed from the front, the toadfish appears to rest on these two fins. Also on the undersurface, towards the rear of the body and along the tip of the tail, there is a small and rounded caudal fin.
It grows to a length of about 12 inches (31cm). Like most species of fishes that dwell close to the sand, the splendid toadfish has eyes located on the top of its head which look directly upwards as there is little need for them to have primary horizontal vision. They possess small, sharp teeth that line their wide, powerful jaws.
These toadfish are commonly found inside crevices or cracks at the base of coral heads, under coral outcroppings or at the base of long sloping sand patches. Their dens will usually extend a long way back into the coral structures giving the toadfish room to retreat to safety if threatened. These crevices are most likely to be located low on sand and rubble bottoms along the sides of shallow and medium-deep strip reefs, or under coral heads closer to shore.
They can often be heard long before they are seen. This is because the males frequently emit a low guttural mating call reverberating through the water. This grunting noise is the reason for the name ‘toadfish.’ When you hear this sound, it lets you know that one of more of these fish are close by.
Very few reef fish in Cozumel are as highly sought after as photographic and video subjects. The toadfish is commonly seen peering from the entrance of the low crevices, perched on its pectoral or ventral (caudal) fins. Divers need to get very close to the bottom to get a close-up look. If you approach too quickly, they will often withdraw further into their dens. As most divers will attest, toadfish are very difficult to entice out in the open. Some dive masters will dangle a plastic squid lure in front of them to try to entice them to come forward and investigate what they may perceive as food.
Toadfish usually feed by ambush, remaining still until their prey comes within range, before making a quick lunge and engulfing the animal in its large jaws. This species’ diet consists mainly of small fish, mollusks, crustaceans and polychaete worms
The splendid toadfish has limited dispersal capabilities (the ability to extend their range). This is because both the eggs and larvae remain attached to something on the seabed, rather than drifting in currents in the water column. This explains in part why their numbers have not spread to other areas of the Caribbean. During the development of the eggs, they are guarded by the male. Once hatched the larvae stay attached to the substrate until most of the yolk reserves have been absorbed, at which point they measure around 1.2 to 1.6 centimeters in length.
The best places to look for splendid toadfish in Cozumel is on the outer sides of shallow, low profile strip reefs like Tormentos Reef, Punta Tunich, Paso Del Cedral, Yucab and Paradise Reef. It is difficult to find these illusive fish hiding in their low lying crevices and caves. Most divers new to the area may not discover one unless a dive guide points it out. Take your time in the shallows away from the edges of shallow strip reefs and listen for the distinctive croaking sound emitted by toadfish. Adjust your buoyancy and settle close to the sandy bottom, swim slowly and peer under ledges to look for the fish peeking from caves and crevices near the sandy bottom. They are pretty difficult to coax from their dens during the day, but at night when they are more active they can frequently be seen hunting out in the open. Since these fish are nocturnal predators, night dives are a good time to spot one. Look for toadfish prowling the reef in search of food. Let your dive guides know that you’re interested in observing or photographing toadfish and they will do their best to help you find subjects and get opportunities for photographs.
For more information about Splendid Toadfish and other interesting and colorful reef fish, download a copy of the eBook, Dive Cozumel, which you can get from iTunes, Google Play Store and Amazon (Kindle)
You can also find a link to these sites from our website at http://www.rosenbergebooks.com/