The compass jellyfish is easy to recognize by the brown v-shaped markings found running from the center of the jellyfish down to the outer edge. This jellyfish has long stinging tentacles hanging from the rim. The catching arms around the mouth opening resemble a bridal veil and can grow much longer than the tentacles. A compass jellyfish begins life as a male but eventually turns female in the course of its one year of life.

Jellyfish are propelled through the water by means of pulsations of the bell. They often become washed ashore by wind and storms, where they die. This jellyfish catches its food with its tentacles, which can be extended and retracted. A range of planktonic animals are caught in this way before being transferred to the central arms around the mouth. Adults are hermaphrodites, and function initially as males before becoming functional females. Sperm is released from the mouth of a functional male, and drawn into a female, also through the mouth (the mouth being the only external opening). Fertilisation then takes place inside the female. Free-swimming larvae (planulae) are released from the female during summer or autumn. They remain in the plankton for just a few days before settling as a polyp known as a scyphistoma. During the following spring, the scyphistoma produces tiny jellyfish (ephyrae) by a form of asexual reproduction. These tiny jellyfish detach, and quickly develop into mature jellyfish by summer. The compass jellyfish lives for around one year (2).

The compass jellyfish has a saucer-shaped bell, with 32 semi-circular lobes around the fringe, each one with a brown spot (2). On the upper surface of the bell, 16 brown V-shaped marks radiate outwards from a dark central spot. The mouth, the only opening to the exterior, is located on the centre of the underside of the bell, and is surrounded by 4 arms. There are also 24 tentacles around the edge of the bell, grouped in threes. The colour of this jellyfish varies, with a variable level of brown pigment (2).

 Chrysaora hysoscella has a thickened bell (manubrium) that can grow up to 30 cm in diameter. The edges of the bell are developed into 32 lobes and bear 24 marginal tentacles. These are arranged in eight groups of three which alternate with eight sensory organs and are capable of great elongation. The marginal tentacles are conical in shape with a flattened thicker base giving the jellyfish a fluted appearance. They are also covered with clusters of stinging cells (nematocysts). It has a long and slender manubrium which leads onto 4 oral arms that are fused for a short distance at its base. Typically Chrysaora hysoscella is yellowish white in colour with a highly distinctive brown pattern like the radii of a compass.May be confused with the common jellyfish Aurelia aurita when stranded. Aurelia aurita however, has shorter tentacles with no brown v-shaped markings on the bell. Instead it has 4 purplish-blue horseshoe shaped gonads that are easily distinguished through the upper surface of the bell. The stinging cells and venom of Chrysaora hysoscella are strong and can produce painful, long lasting weals in humans.

The compass jellyfish has a series of V-shaped brown marks in a radial pattern on the disk.

Cosmopolitan species.

Belgian Coast, Belgian Exclusive Economic Zone, Birkenfels (shipwreck), De Panne, Dutch Exclusive Economic Zone, East North Atlantic, European waters (ERMS scope), Grevelingen, Irish Exclusive economic Zone, Koksijde, Mediterranean Sea, Oostende, Sas van Goes, South Atlantic, United Kingdom Exclusive Economic Zone, Wimereux

Although it has been recorded from around all of the coasts of Britain, it is more frequently found in the south and west (2).

Umbrella flat smooth and thick, 15-49cm in diametar, the color is variable, but is characterized by 16 v-shaped gold-brown or yellow-brown marks on the upper umbrella, radiating from the central region, there are 24 marginal tentacles, which are easly broken off, and thirty-two pigmented semi-circular marginal lappets.

coastal

Depth range based on 5 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 18 - 39

Graphical representation

Depth range (m): 18 - 39
 
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 Chrysaora hysoscella is a pelagic species. Young Chrysaora appear in British waters in May.

Inhabits inshore waters (2).

Common and widespread (2).

This species is not currently threatened.

Conservation action has not been targeted at this common and widespread species.