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Gobiomorphus cotidianus

  • Fish
  • Water temperature15–18 °C
  • Best monthsFebruary, March, and April
  • How commonRare
All species

Photo credit: (c) Shaun Lee, some rights reserved (CC BY), uploaded by Shaun Lee · CC BY · iNaturalist

About this species

The common bully, or toitoi (Māori), is a fish endemic to New Zealand, and is present throughout the country. There are three other bully species that can be confused with common bullies. There are few characteristics of the common bully that separate it from other species. Vertical lines present on the cheek are a good defining characteristic, along with the location of head pores and scale patterns on the head although these are hard to establish when seen in the wild. It is an amphidromous fish meaning it is able to survive in marine and fresh water environments. It is a small fish only growing as big as 15 cm. It can live in marine, fresh water or brackish water habitats and generally lives in benthic zones. Some populations venture into the sea and occur in coastal rivers and streams while other land-locked populations have established in many shallow mainland lakes. They generally prefer moderate to slow moving water which means they are the most likely bully species to be sighted. Its diet consists mainly of small benthic invertebrates but also involves insect larvae and crustacea.

Text from the Wikipedia article “Common bully”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

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Best months

Worldwide (open data)

  • January: 14 records
  • February: 20 records
  • March: 31 records
  • April: 31 records
  • May: 15 records
  • June: 6 records
  • July: 11 records
  • August: 20 records
  • September: 11 records
  • October: 9 records
  • November: 16 records
  • December: 12 records

Depth and water temperature

Water temperature

Recorded in surface water of 15–18 °C

  • 14–16 °C: 2 records
  • 16–18 °C: 3 records

Names and classification

Similar species

Sources and credits

Names and taxonomy: WoRMS (CC BY 4.0) and the GBIF Backbone (CC BY 4.0). Photos: iNaturalist observers, each under the licence shown (CC0, CC BY or CC BY-SA).

  • Depth, temperature, months and maps: records from OBIS and GBIF under CC0 or CC BY.
  • Descriptions: Wikipedia, licensed CC BY-SA, each linked to its article.
  • 5 open-data records from 1964 to 1992.

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