New Zealand Pygmy Sleeper

Thalasseleotris iota

The New Zealand Pygmy Sleeper is a small reef-associated fish found in the coastal waters of New Zealand. It reaches a maximum length of 3.3 cm and is known for its cryptic appearance, which includes a semi-transparent body and camouflage coloration. This makes it difficult to spot underwater, although it can be collected using rotenone ichthyocide. The species can be distinguished from similar species like T. adela by its narrower gill opening, less extensive body scaling, and distinctive fin markings, such as the absence of a black spot on the first dorsal fin and the presence of small black spots on the ventral midline of the caudal peduncle. This fish inhabits rocky reefs with plenty of holes, crevices, and small caves, often perching on rocky ledges covered by silty sand or shell debris. It is typically found at depths ranging from 2 to 34 meters. The New Zealand Pygmy Sleeper is observed to be solitary and possibly territorial, often sharing its habitat with larger black gobies. Despite its elusive nature, it is a harmless species and has been assessed as Least Concern by the IUCN. Divers encountering this species may find it challenging to spot due to its small size and cryptic behavior. It is often found in environments similar to those of T. adela in Australia, favoring silty, turbid waters.