''Cyclichthys orbicularis'', known commonly as the birdbeak burrfish among other vernacular names, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Diodontidae.

Description

The Birdbeak burrfish is a medium size

and can grow to be up to long. It has a small mouth. This round fish is covered in short spines, each of which has a triangular base. All of the spines on the top of the head have three subdermal roots. It is pale brown above and white below and has round brown spots scattered across the body, especially towards the tail. The fins are translucent.

Distribution and habitat

The Birdbeak burrfish is widespread throughout the

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

waters of the Indo-West Pacific region from

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

to the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

. It is also one of the more common visitors to the waters around

Cape Town Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. It is usually found on coastal shelves, occurring from the surface to a depth of around . It most commonly occurs in areas where the sea floor is covered in a soft sediment, such as sand, but may also occur above reefs.

Ecology

This species is able to inflate itself by ingesting water. In this state, it is spherical and its spines are erect. It moves little when inflated. It is sometimes trawled in large numbers. A nocturnal species. Active at night and twilight.

Early development

A study published in 2015 examined the development of offspring produced by a wild-caught but captive pair of birdbeak birdfish. The two individuals lay together on the sediment the day before spawning and produced two spawns of fertilised eggs. The embryo and primordial eyes formed within a day of spawning, with the larvae hatching the next day. They were, on average, long. At this point, the mouth and anus were still closed and the head and trunk were covered by a vestibular dermal sac. Membranous pectoral fins were clearly visible.

Melanophores Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in contrast ...

and

xanthophores Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in contrast ...

were scattered across the body and the eyes were unpigmented. The eyes became pigmented and the mouth opened within 19 hours of hatching. Two days after hatching the dorsal and anal fins were separated. After five days soft rays became visible in the pectoral fins and the young fish had reached a length of . The dorsal and anal fins also had soft rays a week later. At seventeen days after hatching, 21 pectoral, 12 dorsal and 10 anal soft rays were present and the spines started to emerge. They had grown to a length of . They become rigid by day 39 after hatching, although they continued to grow develop beyond this point. The fish were long at this age.

References

External links

*http://www.marinespecies.org/aphia.php?p=taxdetails&id=219968 * * Video of Cyclichthys orbicularis in aquarium: https://www.youtube.com/watch?v=n2RPfOBnTcA * Shortspine Porcupinefish, Cyclichthys orbicularis (Bloch 1785) @ fishesofaustralia.net.au
/small> Diodontidae Marine fish of East Africa Fish described in 1785 {{Tetraodontiformes-stub