Pegea pacifica

The Makassar Salp is the largest species of free-floating Tunicate to inhabit tropical waters. Its gelatinous body is typically 5 cm long and prolate, featuring siphons at either end. These can dilate to a degree sufficient to allow other animals to crawl or swim inside the body. Typically such an intruder is ejected during the propulsive process, but on occasion it may become lodged. In these circumstances, the salp’s usual recourse is to expel all water and contract at both ends, suffocating the creature in a vacuum. The salp may itself die in the process, and then harden — resulting in an attractive, semi-opaque object shaped exactly like a bird’s egg.

“Mermaid grenades,” as these floating trinkets are often called, are commonly gleaned by fishermen and sold as souvenirs. Their shape and intrinsic beauty can cause them to be mistaken for handmade items. A color illustration by Ernst Haeckel from 1904 (of a dead specimen encasing a Mammoth tomopteris) is well known to the public due to its frequent appearance on Easter cards.

Despite their appeal, dried Makassar salps are very brittle and should be placed out of the reach of children. The “shell” consisting of the actual salp can cause nausea or vomiting if ingested, whereas the trapped contents may be more lethal. The corpse of an Hörkbisschen’s devil prawn, for example, will induce blindness, paralysis and asphyxia in very short order if tasted. Frequently found nested in dead salps, these crustaceans have more than once been mistaken for red licorice “prizes” — with tragic consequences.

From: P. P. Klimpsonel, The Shores of Borneo (New York: Harcourt Brace and World, 1969), p. 83.