About Solenostomus cyanopterus Bleeker, 1854
Solenostomus cyanopterus Bleeker, 1854, commonly called the robust ghost pipefish, is the largest species of ghost pipefish. It can reach a maximum total length of 17 cm (6.7 in). This species has a long snout with the mouth located at the tip, and its jaws are mostly toothless. It also has a tail that is long relative to its body. The caudal fin may take a truncated, rounded, or lanceolate shape, and the caudal peduncle is very short, and sometimes completely absent. Its overall appearance, featuring a long slender snout and large fins, lets it mimic a piece of drifting seagrass. The body can be colored gray, brown, pink, yellow, or bright green, marked with small black and white dots. Robust ghost pipefish can change their color gradually over 24 to 36 hours to match their surrounding environment. Several dark-blue spots are present on the first few spiny rays of the dorsal fin; these spots may look black in preserved specimens. The species is largely scaleless, but has 25–35 star-shaped (stellate) bony plates across its skin. The lateral line is not visible. This species is found in the Red Sea and throughout the tropical Indo-Pacific, ranging from the coast of East Africa to Fiji, southern Japan, and Australia. Within this broad range, it can adapt to a variety of habitats. Larvae and young individuals are mostly pelagic, while adults inhabit coastal reefs and weedy areas at depths between 2 and 25 m (6 ft 7 in to 82 ft 0 in). Preferred substrates for adults include coral, vegetation, and sand. The robust ghost pipefish is a slow-moving, placid species. When disturbed, it typically moves into nearby shelter, such as seagrass for extra camouflage or coral for protection. It has a relatively short lifespan, and dies after a single reproductive event. Among all fishes in the order Syngnathiformes, this genus (Solenostomus) is unique because females, not males, care for the eggs. In females, the two pelvic fins fuse together to create a brood pouch that protects the eggs. Each robust ghost pipefish reproduces only once in its lifetime, and mating pairs stay together for life. Egg envelopes attach to small skin extensions that only exist in female specimens, so eggs can incubate safely inside the brood pouch. When the eggs are ready to hatch, the female releases them into the water column, where newly hatched larvae drift along with currents. The larvae are well-developed when released, measuring approximately 3 mm long, with fully formed eyes, mouths, and spines.
