# Dusky spinefoot > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Dusky_spinefoot > Markdown URL: https://mediated.wiki/source/Dusky_spinefoot.md > Source: https://en.wikipedia.org/wiki/Dusky_spinefoot > Source revision: 1355340020 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Species of fish}} {{Speciesbox | image = Siganus luridus Karpathos 02.jpg | image_caption = A dusky spinefoot in [Greece](/source/Greece) | status = LC | status_system = IUCN3.1 | status_ref = {{cite iucn |author=Obota, C. |author2=Carpenter, K.E. |author3=Borsa, P. |author4=Jiddawi, N. |author5=Yahya, S. |author6=Smith-Vaniz, W.F. |date=2018 |title=''Siganus luridus'' |volume=2018 |article-number=e.T18178550A46663979 |doi=10.2305/IUCN.UK.2018-2.RLTS.T18178550A46663979.en |access-date=19 November 2021}} | taxon = Siganus luridus | authority = ([Rüppell](/source/Eduard_R%C3%BCppell), 1829) | synonyms = *''Amphacanthus luridus'' Rüppell, 1829 *''Teuthis lurida'' (Rüppell, 1829) *''Amphacanthus abhortani'' [Valenciennes](/source/Achille_Valenciennes), 1835 | synonyms_ref = {{FishBase|Siganus|luridus|month=June|year=2021}} }} The '''dusky spinefoot''' ('''''Siganus luridus'''''), also known as the '''squaretail rabbitfish''', is a species of marine [ray-finned fish](/source/ray-finned_fish), a [rabbitfish](/source/rabbitfish) belonging to the [family](/source/Family_(taxonomy)) [Siganidae](/source/Siganidae). It is native to the western [Indian Ocean](/source/Indian_Ocean) which has spread to the [Mediterranean Sea](/source/Mediterranean_Sea) through the [Suez Canal](/source/Suez_Canal) ([Lessepsian migration](/source/Lessepsian_migration)). Its fin spines contain venom. It is regarded as a food fish. ==Taxonomy== The dusky spinefoot was first formally [described](/source/Species_description) in 1829 as ''Amphacanthus luridus'' by the German [naturalist](/source/naturalist) and [explorer](/source/explorer) [Eduard Rüppell](/source/Eduard_R%C3%BCppell) with the [type locality](/source/Type_locality_(biology)) given as the [Red Sea](/source/Red_Sea).{{Cof genus | genus = Siganus | access-date = 29 August 2021}} The [specific name](/source/Specific_name_(zoology)) ''luridus'' means "pale yellow", this name was given to it by the collector of the [type specimen](/source/type_specimen), [Christian Gottfried Ehrenberg](/source/Christian_Gottfried_Ehrenberg), According to [Achille Valenciennes](/source/Achille_Valenciennes) in 1835, Ehrenberg described the colour of the body as yellowish-brown, with numerous very thin pale yellow lines. However, Rüppell said that the colour was bluish black with some irregular, paler spots and a yellowish ring around pupil in his description.{{cite web | url = https://etyfish.org/acanthuriformes2/| title = Order Acanthuriformes (part 2): Families Ephippidae, Leiognathidae, Scatophagidae, Antigoniidae, Siganidae, Caproidae, Luvaridae, Zanclidae and Acanthuridae | work = The ETYFish Project Fish Name Etymology Database | editor1= Christopher Scharpf | editor2 = Kenneth J. Lazara | name-list-style = amp |date = 12 January 2021 | access-date = 29 August 2021 | publisher = Christopher Scharpf and Kenneth J. Lazara}} ==Description== The dusky spinefoot has a compressed body which Has a depth which fits into its standard length 2.1 to 2.8 times. There is a single row of [incisor](/source/incisor)-like teeth in the jaws, each with 1 or 2 lateral cusps.{{cite web | author = J.C. Hureau | title = Dusky Spinefoot (''Siganus luridus'') | url = http://species-identification.org/species.php?species_group=fnam&id=1939 | work = Fishes of the NE Atlantic and the Mediterranean | access-date = 29 August 2021 | publisher = Marine Species Identification Portal}} The [dorsal fin](/source/dorsal_fin) contains 13-14 spines and 10 soft rays while the [anal fin](/source/anal_fin) has 7 spines and 9 soft rays. The [caudal fin](/source/caudal_fin) is truncate. This species attains a maximum total length of {{cvt|30|cm}}, although {{cvt|20|cm}} is more typical. The colour is variable, it is normally olive green to dark brown with a mottled pattern. The [pectoral fin](/source/pectoral_fin)s are [hyaline](/source/hyaline)-yellow and there are dark bars on the caudal fin ==Distribution and habitat== The dusky spinefoot is found on the coast of eastern Africa from Mozambique northwards into the Red Sea, and also the Comoros, Madagascar, and the [Mascarene Islands](/source/Mascarene_Islands). Its presence in the [Persian Gulf](/source/Persian_Gulf) needs to be confirmed. Recorded first in the [Mediterranean Sea](/source/Mediterranean_Sea) in 1955 off Israel, following entry via the Suez Canal, it fast expanded across the eastern Basin and now reaches westwards as far as the French Mediterranean coast and the [Adriatic Sea](/source/Adriatic_Sea).Atlas of Exotic Fishes in the Mediterranean Sea (''Siganus luridus''). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Siganus_luridus.pdf It is found at depths between {{cvt|2|and|40|m}} in waters over hard substrates, such as coral and rocky reefs. ==Biology== The dusky spinefoot spawns in April and from June to August when the seawater temperature is between {{cvt|24|and|29|C}}, the eggs and larvae are planktonic. The larvae stay close to the surface where they feed on phytoplankton and zooplankton from 3 days old. The adults are herbivores which are active during the day, hiding in cavities during the hours of darkness. They are frequently encountered in schools but solitary individuals can also be seen, grazing on algae from the substrate. It feeds on larger [brown algae](/source/brown_algae) species, as well as other [macrophytes](/source/macrophytes).{{cite journal | last1 = Serhan Tarkan | first1 = Ali | url = https://www.cabi.org/isc/datasheet/64220#tosummaryOfInvasiveness | title = Siganus luridus dusky spinefoot | work = CABI Compendium | date = 2016 | volume = CABI Compendium | access-date = 29 August 2021 | publisher = [CABI](/source/Centre_for_Agriculture_and_Bioscience_International) | doi = 10.1079/cabicompendium.64220 | doi-access = free }} ===Venom=== This species produces [venom](/source/venom) in the spines of its fins. In a study of the venom of a [congener](/source/Congener_(biology)) it was found that rabbitfish venom was similar to the venom of [stonefishes](/source/stonefishes).{{cite journal | author1 = Kiriake A | author2 = Ishizaki S | author3 = Nagashima Y | author4 = Shiomi K | title = Occurrence of a stonefish toxin-like toxin in the venom of the rabbitfish ''Siganus fuscescens'' | journal = Toxicon | year = 2017 | volume = 140 | pages = 139–146 | doi = 10.1016/j.toxicon.2017.10.015 | pmid = 29055787| bibcode = 2017Txcn..140..139K | s2cid = 205439876 }} This species has been observed stopping suddenly. erecting the dorsal, anal and pelvic to present a potential threat with an array of venomous spines around its body. ===Predators and parasites=== The venomous spines are used for defence against predators so the highest predation pressure is on the planktonic and larval stages. Known parasites of the dusky spinefoot included the [monogenean](/source/Monogenea) ''[Glyphidohaptor plectocirra](/source/Glyphidohaptor_plectocirra)'' and ''[Tetrancistrum polymorphum](/source/Tetrancistrum_polymorphum)'' as well as the [digeneans](/source/Digenea) ''[Hexangium brayi](/source/Hexangium_brayi)'', ''[Hexangium sigani](/source/Hexangium_sigani)'' and ''[Progyliauchen magnacetabulum](/source/Progyliauchen_magnacetabulum)''.{{cite WoRMS||author=Nicolas Bailly|year=2008 |title=Siganus luridus |id=127044 |access-date=29 August 2021}} ==Utilisation== The dusky spinefoot is caught using set [fish trap](/source/fish_trap)s, [gillnet](/source/gillnet)s and beach [seines](/source/Seine_net), the catch is sold as fresh fish. This species has become an important species for fisheries in the Mediterranean while in other areas, such as Kenya, it is a [bycatch](/source/bycatch). This species has been implicated in cases of mild ciguatera like poisoning when consumed.{{cite journal |author=A. Herzberg|year=1973|title=Toxicity of Siganus luridus (Rüppell) on the Mediterranean coast of Israel|journal=Aquaculture|volume=2|pages=89–91|doi=10.1016/0044-8486(73)90127-0 |bibcode=1973Aquac...2...89H }} ==References== {{commons category|Siganus luridus}} {{Reflist}} ==External links== * {{sealifephotos|127044}} {{Taxonbar|from=Q2289387}} Category:Siganidae Category:Fish described in 1829 Category:Taxa named by Eduard Rüppell Category:Western Indo-Pacific fauna --- Adapted from the Wikipedia article [Dusky spinefoot](https://en.wikipedia.org/wiki/Dusky_spinefoot) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Dusky_spinefoot?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.