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Lined sole, Achirus lineatus. Illustration courtesy NOAA.

Species Name: Achirus lineatus
Achirus lineatus Linnaeus, 1758
Common Name: Lined Sole
Synonymy: Pleuronectes lineatus Linnaeus, 1758
Pleuronectes nigricans Bloch & Schneider, 1801

    Kingdom Phylum/Division Class: Order: Family: Genus:
    Animalia Chordata Actinopterygii Pleuronectiformes Achiridae Achirus

    Species Description

    The lined sole, Achirus lineatus, is a member of Family Achiridae, the American soles. Previously it was included within family Soleidae. As with all soles, A. lineatus is a right-eyed species, with the dorsal or eyed side of the flat benthic animal corresponding to the right side of a fish with a typical body plan and orientation.

    The body is entirely scaled, and body coloration on the eyed side is usually olive to brown, with variable dark blotches and spots and diffuse lines. Conspicuous tufts of hairlike cirri are usually scattered on the body surface. Pectoral fins are present (Hoese and Moore 1977, Robbins et al. 1986).

    Ray counts are variable, with dorsal soft rays numbering 52-58 and anal soft rays numbering 39-44 (Froese and Pauly (2008). Ray count ranges presented in Hoese and Moore (1977) differ slightly, with dorsal soft rays numbering 50-58 and anal soft rays numbering 38-48. The pectoral fin on the eyed side possesses 5-6 soft rays (Hoese and Moore 1977).

    Potentially Misidentified Species

    Careful examination allows Achirus lineatus and other right-eyed achirids to be distinguished from all co-ocurring flatfish of the families Bothidae (lefteye flounders) and Cynoglossidae (tonguefishes), all of which have the left side up. The right-eyed flounders of family Pleuronectidae typically inhabit colder waters than A. lineatus (Robbins et al 1986).

    ithin the Achiridae, the absence of vertical body bars should be sufficient to distinguish A. lineatus from three co-occurring species, the naked sole (Gymnachirus melas), fringed sole (G. texae), and hogchoker (Trinectes maculatus). Lined sole are also easily differentiated from scrawled sole (Trinectes inscriptus), whose side-up body is covered by a network of irregular dark lines (Robbins et al 1986).


    Regional Occurrence

    Achirus lineatus is a western Atlantic species occurring in Florida and in the northern Gulf of Mexico southward to northern Argentina (Froese and Pauly 2008).

    IRL Distribution

    Lined sole may be encountered throughout the subtidal benthic IRL environment.


    Age, Size, Lifespan

    Froese and Pauly (2008) note a maximal total length of 23 cm.


    Seasonal field sampling in coastal and inshore Louisiana waters by Gunter (1938) revealed Achirus lineatus to not be among the more common species. Peak abundance occurred in the fall, from September through November. More recent collections from Florida Bay and Louisiana also indicate A. lineatus is typically not a numerically dominant estuarine ichthyofaunal component (Peterson and Turner 1994, Matheson et al. 1999).

    In contrast, Machado et al. (2002) indicate A. lineatus was ranked 23rd of the 39 most abundant demersal fish species collected from Sepetiba Bay, Brazil from 1993-1996, occurring in 43.5 of trawl samples taken. Stoner (1986) also reports A. lineatus as the dominant fish species in Laguna Joyuda estuary, Puerto Rico, accounting for greater than half the collection totals at some sampling stations.


    Reproduction appears to occur year-round, at least in some portions of the animal's distributional range. Stoner (1986) found small juveniles (<26 mm SL) in all months except October in Laguna Joyuda estuary, Puerto Rico. Published information regarding other reproductive aspects in this species is sparse.


    Keith et al. (2000) indicate a brief planktonic larval duration for the species. Migration of the left eye to a position adjacent to the right eye on the new top side of the animal occurs during this period (Robbins et al. 1986).



    The restricted subtropical to tropical distribution of the A. lineatus suggests a somewhat narrow thermal tolerance for the species. Froese and Pauly (2008) indicate 30°N as the northern distribution limit.


    Achirus lineatus is a broadly euryhaline species, i.e., having a wide salinity tolerance. Individuals have been collected in near-fresh water from the upper portions of the St. Lucie and Caloosahatchee estuaries, Florida (Gunter and Hall 1963), and aquarium hobbyists sometimes refer to A. lineatus as a freshwater sole. At the other end of the salinity spectrum, Cervigon et al. (1992) note the presence of A. lineatus in hypersaline lagoons.

    Although Ronnins et al. (1986) note individuals rarely occur in coastal waters of less than 15 ppt, Stoner (1986) indicates A. lineatus is a year-round resident of seasonal wet/dry-influenced laguna Joyuda, Puerto Rico where salinity is estimated to range between 4 ppt and 44 ppt.


    Trophic Mode

    Achirus lineatus is a benthic predator that feeds primarily on worms, crustaceans, and small fish.


    Lined sole are likely to compete for suitable benthic prey with co-occurring flatfishes and other bottom-feeding fish species.


    The Nematode Procamallanus (=Procamallanus) pereirai has been reported as a parasite of Tampa Bay Achirus lineatus (Hutton 1964).


    Achirus lineatus inhabits reefs, coastal and estuarine seagrasses and sand and mud bank habitats to a depth of 20 m. It is a cryptic species capable of blending in with occupied sand and mud habitats, and often buries itself in the sand with only its eyes exposed (Kritzler 1951, Tolan et al. 1997, Matheson et al. 1999, Froese and Pauly 2008).

    Activity Time

    Lined sole are typically active in the evening hours, spending much of the daytime hours buried in shallow sand.


    Special Status


    Economic Importance

    Related to commercially important soles, but Achirus lineatus itself is of relatively little market value.


    Cervigon F, Cipriani R, Fischer W, Garibaldi L, Hendrick M, Lemus AJ, Marquez R, Poutiers JM, Robaina G, and B Rodriguez. 1992. Fichas FAO de identificacion de especies para los fines de la pesca. Guia de campo de las especies comerciales marinas y de aquas salobres de la costa septentrional de Sur America. FAO, Rome. 513 p.

    Froese, R. and D. Pauly. Editors. 2008.FishBase. World Wide Web electronic publication. Available online.

    Gunter G. 1938. Seasonal variations in abundance of certain estuarine and marine fishes in Louisiana, with particular reference to life histories. Ecological Monographs 8:314-346.

    Gunter G and GE Hall. Additions to the List of euryhaline fishes of North America. 1963. Copeia 1963:596-597.

    Hoese HD and RH Moore. 1977. Fishes of the Gulf of Mexico. Texas, Louisiana, and Adjacent Waters. Texas A&M University Press, College Station TX. 327 p.

    Robert F. Hutton. 1964. A Second list of parasites from marine and coastal animals of Florida. Transactions of the American Microscopical Society 83:439-447.

    Keith P, Le Bail O-Y, and P Planquette, 2000. Atlas des poissons d'eau douce de Guyane (tome 2, fascicule I). Publications scientifiques du Museum national d'Histoire naturelle, Paris. 286 p.

    Kritzler H. 1951. Three rare fishes (Nodogymnus, Pareques, and Canthidermis) from the Florida east coast. Copeia 1951:245-246.

    Changes in seagrass-associated fish and crustacean communities on Florida Bay mud banks: The effects of recent ecosystem changes?

    Matheson RE, Jr., Camp DK, Sogard SM, and KA Bjorgo. 1999. Estuaries 22: 534-551. No. 2, Part B: Dedicated Issue: Florida Bay: A Dynamic Subtropical Estuary.

    Peterson GW and RE Turner. 1994. The value of salt marsh edge vs. interior as a habitat for fish and decapod crustaceans in a Louisiana tidal marsh. Estuaries 17:235-262.

    Robins CR, Ray GC, and J Douglas. 1986. A Field Guide to Atlantic Coast Fishes. The Peterson Field Guide Series. Houghton Mifflin Co., Boston. 354 p.

    Tolan JM, Holt SA, and CP Onuf. 1997. Distribution and community structure of ichthyoplankton in Laguna Madre seagrass meadows: Potential impact of seagrass species change. Estuaries 20:450-464.

Report by:  J. Masterson, Smithsonian Marine Station
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Page last updated: October 1, 2008

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