Taxonomy

Plotosus lineatus | Striped eel catfish | Cat mara coiréalach

Pre 2017

2017 - 2020

Status

Legal status

Regulated invasive species of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].

Native status

Non-native

First reported in the wild

Not present in Ireland or Northern Ireland

Invasiveness

Invasive species - risk of High Impact

Irish status

Absent

Introduction pathways - 1

Corridor

Introduction pathways subclass - 1

Natural dispersal across borders of invasive aliens

Introduction pathways - 2

Unaided

Introduction pathways subclass - 2

Natural dispersal across borders of invasive aliens

NAPRA Ireland risk assessed

No

Species Biology

Identification

Plotosus lineatus is a species of bony fish in the Plotosidae family that can grow to approximately 32 cm in length (Encyclopedia of Life, 2021). The juveniles of this species are highly distinctive with vibrant white and black stripes (Invasive Species Ireland, 2021). This fades to less vibrant shades of brown and black as they mature, making them less conspicuous (Invasive Species Ireland, 2021). Juveniles can be seen in large ball-shaped schools od up to 100 individuals, making them rather easy to identify (World Register of Marine Species, 2021). The adults are more solitary and will be found in smaller groups of about 20 individuals (World Register of Marine Species, 2021). Upon close inspection, four pairs of barbels can be seen on the mouth as well as venomous spines on the dorsal fins (World Register of Marine Species, 2021).

Diet

This carnivorous species feeds on crustaceans, molluscs, polychaetes and small fish (World Register of Marine Species, 2021).

Ecology

Adult individuals are nocturnal and will typically position themselves under ledges or in caves during daylight hours (Galanidi and Zenetos, 2018).

Impacts

Biodiversity - Although further study is required to quantify this, it is thought that at high densities, Plotosus lineatus may work to harm native populations of small fish, crustaceans, molluscs etc. through predation and competitive exclusion (Galanidi and Zenetos, 2018). 

Ecosystem - If the population is large enough to support large feeding swarms of Plotosus lineatus, ecosystem functioning can be negatively impacted as these swarms may increase turbidity and alter sediment properties (Galanidi and Zenetos, 2018). This can lead to issues with nutrient cycling and mobilisation of eggs of various species (Galanidi and Zenetos, 2018).

Economic - Due to its venomous nature, Plotosus lineatus must be carefully handled when removing from fishing nets and sorting (Galanidi and Zenetos, 2018). This, combined with the high volumes of this species that can be caught by trawlers, results in losses of working time due workers needing to operate more carefully and injuries from the venom (Galanidi and Zenetos, 2018). 

Habitat

In its native range, Plotosus lineatus can be found living in various costal benthic (bottom of a waterbody e.g. lake beds) habitats such as coral reefs, seagrass beds, estuaries, tide pools and open coasts (Galanidi and Zenetos, 2018).

Reproduction

This species reproduces sexually and reproduction is oviparous and iteroparus (Encyclopedia of Life, 2021). Oviparous refers to a form of reproduction that involves the production of eggs that will then hatch to produce young. Iteroparus simply refers to a species that can undergo multiple reproductive events throughout its life rather than just one.

Mechanism of impact

Competition, Predation, Poisoning/Toxicity

Management approach

Prevention
As Plotosus lineatus is listed as an Invasive Alien Species of Union concern under the EU Regulations of Invasive Alien Species, it cannot be imported, traded, or released to the wild. Measures must also be taken to prevent spread of existing populations of it (European Commission, 2017).
The above mentioned regulations can be enforced by improving biosecurity at potential pathways of introduction for this species in order to reduce the possibility that they can enter the environment that you wish to protect (Galanidi et al., 2019). Additionally, public awareness can be a powerful tool in combatting the spread of invasive species (Galanidi et al., 2019). Awareness campaigns may be set up that give information on the target species such as key identification tips, what a person should do if they see one etc. Citizen Science portals can be a valuable form of early warning system as if the public are aware that this species exists and have the means to easily record it, it is much more likely that a management plan/quarantine can be put in place rapidly and hopefully get on top of the issue before it is too late (Galanidi et al., 2019). 

Control after detection
A species such as Plotosus lineatus may prove difficult to control if it is already present in an area where it is non-native. Eradication is possible in specific circumstances where the species is present in a more controllable area, in small enough numbers that it can be eradicated and where funding is available to support such an undertaking (Galanidi et al., 2019). With this said, efforts to eradicate this species are generally thought to be difficult-unrealistic depending on the specific circumstances and prevention of the species entering the environment in the first place is by far the best control option (Galanidi et al., 2019).

Broad environment

Marine

Species group

Vertebrate

Native region

Tropical Asia, Africa, Pacific Islands

Similar species

No other Plotosus specie have been introduced outside of their native range and therefore Plotosus lineatus should not be misidentified if it was to become established in Ireland (Galanidi and Zenetos, 2018).

Distribution

World distribution(GBIF)

Plotosus lineatus has been recorded as a non-native species in Egypt, Israel, Lebanon, Syria, Turkey and Tunisia (Galanidi and Zenetos, 2018)

Irish distribution

Absent

Native distribution

Plotosus lineatus is native to the Indo-Pacific and is distributed along the Red Sea and East Africa to Samoa, southern Japan and southern Korea, and the Ogasawara Islands, south to Australia and Lord Howe Island (Galanidi and Zenetos, 2018). It has been recorded entering freshwaters of eastern Africa and Madagascar (Galanidi and Zenetos, 2018).

Temporal change

Records submitted to Data Centre in 2021

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

Report any sightings of this species to the National Biodiversity Data Centre, including a photograph, if possible.

If you own one, do not allow it to reproduce or enter the natural environment, it is illegal to do so.

Avoid purchasing this species for any purpose.

References

Publications

Encyclopedia of Life, 2021. Striped catfish - Encyclopedia of Life. [online] Available at: <https://eol.org/pages/46581859> [Accessed 9 Jul. 2021].

European Commission, 2017. Invasive Alien Species of Union concern. [online] Luxembourg. Available at: <https://ec.europa.eu/environment/nature/pdf/IAS_brochure_species.pdf> [Accessed 25 Jun. 2021].

Galanidi, M., Turan, C., Ozturk, B. and Zenetos, A., 2019. Europen Union (EU) Risk Assessment of Plotosus lineatus (Thunberg, 1787); a summary and information update. Journal of the Black Sea/Mediterranean Environment, [online] pp.210–231. Available at: <https://www.researchgate.net/publication/334811880_Europen_Union_EU_Risk_Assessment_of_Plotosus_lineatus_Thunberg_1787_a_summary_and_information_update> [Accessed 9 Jul. 2021].

Galanidi, M. and Zenetos, A., 2018. Risk Assessment for Plotosus lineatus (Thunberg, 1787). [online] Available at: <https://circabc.europa.eu/faces/jsp/extension/wai/navigation/container.jsp?FormPrincipal:_idcl=FormPrincipal:_id1&FormPrincipal_SUBMIT=1&id=f009176e-eade-498a-a409-cb125f9eb709&javax.faces.ViewState=WmWkzCLDPt4wKaTFG6CSsmIFacN%2ByeNiXbTe%2BluQdPnJd7x%2BYP> [Accessed 9 Jul. 2021].

Invasive Species Ireland, 2021. Plotosus lineatus. [online] Available at: <https://invasivespeciesireland.com/species-accounts/potential/marine/striped-eel-catfish> [Accessed 9 Jul. 2021].

World Register of Marine Species, 2021. Plotosus lineatus (Thunberg, 1787). [online] Available at: <http://www.marinespecies.org/aphia.php?p=taxdetails&id=217659> [Accessed 9 Jul. 2021].