Egg Case
Author: alice Date: 14 November, Category: Educative, Visits 8938
[An egg case or egg capsule, colloquially known as a mermaid's purse or devil's purse, is a casing that surrounds the fertilized eggs of some sharks, skates, and chimaeras. They are among the common objects which are washed up by the sea. They are made of collagen protein strands. Because they are lightweight, they are often found at the strandline, the farthest point of the high tide. The egg cases that wash up on beaches are usually empty, the young fish having already hatched out. Furthermore, egg cases are often found in commercial fishing gears like nets and pots, and on the sea floor during surveys using an ROV.
The size of egg cases vary; those of the small-spotted catshark or lesser spotted dogfish, Scyliorhinus canicula, are around 5 centimetres (2 in) long, while those of the greater spotted dogfish, S. stellaris, are around 10 centimetres (4 in). That excludes the four long tendrils found in each corner, which assist in anchorage. Egg cases from rays vary in that they have points rather than tendrils. The colours and shapes of egg cases also vary greatly from species to species]. – Wikipedia
Callorhinchus millii egg case. Sharks egg found (appropriately enough) near Shark Point, Tasmania, January 2006. (Photo by
Nuytsia)
OBX Skate (Raja eglanteria) Egg Case – Mermaid's Purse. (Photo by
altereye1)
Shark Eggs with Embryos. (Photo by
meixima)
Channeled Whelk with Egg Cases, 2009. [So in this case we know this is a female whelk and each egg case will have up to 100 eggs in it. The average number of eggs per case is much lower though at around 40 according to one NOAA report. Some strings can have up to 120 cases or more cases Most strings will have around 100 cases, but strings with 160 cases have been found as well. This lady whelk was promptly returned to the sea to complete her egg laying mission]. – Eric Heupel. (Photo by
Eric Heupel)
Shark egg case washed up at Long Reef. (Photo by
myopixia)
Skate Egg Case ([Devil's Pocketbook]) in Staten Island, New York, USA. Sept 2011. (Photo by
Tom Turner)
Skate egg case, Nags Head, North Carolina, NC. (Photo by
Becky Gregory)
Shark egg case, 2011. (Photo by
Kirsten)
Swell Shark Egg Case. (Photo by
Ken-ichi Ueda)