Splendid toadfish  (Sanopus splendidus)

Classified as Vulnerable (VU) on the IUCN Red List (1).

With vibrant, bright yellow fins and distinctive patterning, the splendid toadfish is a striking exception to the typical drab colouration exhibited by of most members of the toadfish family (3) (4). In common with other toadfishes, the head is broad and flattened, and bears a number of barbels and other fleshy projections (2). The eyes are located on the top of the head and directed upwards, while the jaws are wide, and bear small sharp teeth (4). Two dorsal fins are found on the midline of the upper body: the first is short, with three sharp spines, and the second is long and flowing, and extends over much of the body. The other fins are also distinctive, with two large, rounded pectoral fins located behind the head, in front of which, on the undersurface, two shorter, pointed pelvic fins are positioned. A long, flowing anal fin is located on the rear undersurface, and there is a small rounded caudal fin at the tip of the tail (2) (4). All the fins have striking, yellow margins, with the exception of the pelvic fins, which are entirely yellow (5). The head is distinctively patterned with densely packed dark and white stripes (3).

The splendid toadfish has a highly restricted distribution, occurring in Caribbean, around Cozumel Island, situated off the eastern coast of the Yucatan Peninsula, Mexico, and around a single reef off the coast of Belize (1) (6) (7).

A tropical marine species, the splendid toadfish is associated with coral reefs, and occurs between depths of 8 to 25 metres, though most commonly between 10 and 15 metres (5).

The splendid toadfish is a sluggish, bottom-dwelling species, which is usually found in or around small rocky caves below coral colonies (2). It usually feeds by ambush, remaining still until prey comes within range, before making a quick lunge and engulfing the animal in its large jaws (2). This species diet mainly consists of small fish, molluscs, crustaceans and polychaete worms (2) (5)

The splendid toadfish has limited dispersal capabilities, as both the eggs and larvae remain associated with the seabed, rather than drifting in currents in the water column. 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 centimetres in length (4).

The highly restricted range of the splendid toadfish means that even a small-scale local environmental disturbance could have a catastrophic effect on its population. At present, the core population of this species around Cozumel Island is threatened by uncontrolled urban growth associated with the burgeoning tourist industry (7) (8). Without intervention, as coastal development continues, sewage discharges will progressively degrade and destroy the splendid toadfish’s coral reef habitat (8).

The range of the splendid toadfish falls within two protected areas, both of which are designated World Heritage sites: Sian Ka’an, around the Yucatan Peninsula; and the Belize Barrier Reef Reserve System (8) (9). Despite the protected status, tourist development remains problematic, although ongoing efforts are being made to manage this threat (8)

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn more about the Sian Ka’an biosphere reserve visit:

• UNEP-WCMC – Protected Areas Programme:
  www.unep-wcmc.org/sites/wh/pdf/Sian%20Ka%27an%20Mexico.pdf