Oophagy ( ) sometimes ovophagy, literally "egg eating", is the practice of

embryos An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

feeding on eggs produced by the

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

while still inside the mother's

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

. The word oophagy is formed from the

classical Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

(, "egg") and classical Greek (, "to eat"). In contrast, adelphophagy is the cannibalism of a multi-celled embryo. Oophagy is thought to occur in all

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

s in the order

Lamniformes The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the gre ...

and has been recorded in the

bigeye thresher The bigeye thresher (''Alopias superciliosus'') is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe ...

(''Alopias superciliosus''), the

pelagic thresher The pelagic thresher (''Alopias pelagicus'') is a species of thresher shark, family Alopiidae; this group of sharks is characterized by the greatly elongated upper lobes of their caudal fins. The pelagic thresher occurs in the tropical and subtr ...

(''A. pelagicus''), the

shortfin mako The shortfin mako shark (; ; ''Isurus oxyrinchus''), also known as the blue pointer or bonito shark, is a large Lamniformes, mackerel shark. It is commonly referred to as the mako shark, as is the longfin mako shark (''Isurus paucus''). The shor ...

(''Isurus oxyrinchus'') and the

porbeagle The porbeagle (''Lamna nasus'') is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent i ...

(''Lamna nasus'') among others. It also occurs in the

tawny nurse shark The tawny nurse shark (''Nebrius ferrugineus'') is a species of carpet shark in the family Ginglymostomatidae, and the only extant member of the genus '' Nebrius''. It is found widely along coastlines in the Indo-Pacific, preferring reefs ...

(''Nebrius ferrugineus''), and in the family

Pseudotriakidae The Pseudotriakidae are a small family of ground sharks, belonging to the order Carcharhiniformes, containing the false catsharks (genera '' Pseudotriakis'' and '' Planonasus'') and gollumsharks (genus ''Gollum''). It contains the only ground s ...

. This practice may lead to larger embryos or prepare the embryo for a predatory lifestyle. There are variations in the extent of oophagy among the different shark species. The grey nurse shark (''Carcharias taurus'') practices intrauterine cannibalism, the first developed embryo consuming both additional eggs and any other developing embryos.

Slender smooth-hound The slender smooth-hound or gollumshark (''Gollum attenuatus'') is a species of ground shark in the family Pseudotriakidae. It is endemic to the waters around New Zealand, where it is usually found close to the bottom over the continental slope ...

s (''Gollum attenuatus''), form egg capsules which contain 30-80 ova, within which only one ovum develops; the remaining ova are ingested and their yolks stored in its external yolk sac. The embryo then proceeds to develop normally, without ingesting further eggs. Oophagy is also used as a synonym of

egg predation Egg predation is a feeding strategy in many groups of animals (ovivores) in which they consume eggs. Since an egg represents a complete organism at one stage of its Biological life cycle, life cycle, eating an egg is a form of predation, the kill ...

practised by some snakes and other animals. Similarly, the term can be used to describe the destruction of non-queen eggs in nests of certain social wasps, bees, and ants. This is seen in the wasp species '' Polistes biglumis'' and ''

Polistes humilis ''Polistes humilis'', known as the common paper wasp, is a species of wasp in the Vespidae family that is found throughout Australia and which has been introduced to northern New Zealand. These paper wasps can be identified by their long thin leg ...

''. Oophagy has been observed in ''

Leptothorax acervorum ''Leptothorax acervorum'' is a small brown to yellow ant in the subfamily Myrmicinae. It was first described by Johan Christian Fabricius in 1793. ''L. acervorum'' is vastly distributed across the globe, most commonly found in the coniferous fore ...

'' and '' Parachartergus fraternus'', where oophagy is practiced to increase energy circulation and provide more dietary protein. ''

Polistes fuscatus ''Polistes fuscatus'', whose common name is the dark or northern paper wasp, is widely found in eastern North America, from southern Canada through the southern United States. It often nests around human development. However, it greatly prefers ...

'' use oophagy as a method to establish a dominance hierarchy; dominant females will eat the eggs of subordinate females such that they no longer produce eggs, possibly due to the unnecessary expenditure of energy and resources.West-Eberhard, M. J. 1969 The social biology of polistine wasps. Mis . Publ.Zool. Univ. Michigan 140, 1-101 This behavior has also been observed in some bee species. Such bee species include ''

Xylocopa sulcatipes ''Xylocopa sulcatipes'' is a large Arabian carpenter bee. These multivoltine bees take part in social nesting and cooperative nesting. They are metasocial carpenter bees that nest in thin dead branches. One or more cooperating females build man ...

'' and '' Bombus ruderatus'', where queen bees will eat larvae deposited by workers or eject them from the nest in order to maintain dominance over the colony.

Notes

{{Feeding Sharks Carnivory Biology terminology

See also

Notes