The New Zealand bigeye (''Pempheris adspersa'') 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

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

, a

sweeper Sweepers are small, tropical marine (occasionally brackish) ray-finned fish of the family (biology), family Pempheridae. Found in the western Atlantic Ocean and Indo-Pacific region, the family contains about 80 species in two genus, genera. One ...

from 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 ...

Pempheridae. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the waters around New Zealand. It inhabitants rocky shores with plentiful overhangs and crevices at depths of from near the surface to .

Description

The New Zealand bigeyes has large eyes, as its name suggests and a deeply keeled and compressed body. Its body is dark in colour and is marked all over with small spots. This species can reach a length of SL.

Distribution

The New Zealand bigeye is endemic to the northeastern coast of the

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

of New Zealand.

Biology

This species is nocturnal. They feed on plankton and some

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

organisms. Some groups have been observed to travel well upstream at night to feed on

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

amphipods Amphipoda () is an order (biology), order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphip ...

, crab larvae, and other

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

. During the day, these fish shelter in crevices or caves, or under overhangs and ledges. When they emerge from their shelter at night, they have been found to use vocalisations and popping to maintain social contact within a shoal. They perceive sounds through a specialisation of the

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

, Baudelot's ligament and their

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

Gravid In biology and medicine, gravidity and parity are the number of times a female has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These two terms are usually coupled, sometimes with additional terms, t ...

females have been collected from mid-November up until February and

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

has been observed to occur at the same time with the juveniles settling from January to April. Juveniles have been recorded from weed growing along rock shorelines in the late (Austral) summer. The bigeyes have also been recorded swimming into estuaries to feed on

among

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

forests. It ranges in depth from

References

{{Taxonbar, from=Q2457620 New Zealand bigeye Endemic marine fish of New Zealand Fish described in 1927