Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: tire track eel

Taxonomy: available through www.itis.gov

Identification: Mastacembelus favus is a large species of eel-like freshwater fish. The body is elongate with 33-37 small isolated dorsal spines in front of a soft dorsal fin; the caudal fin outline merges with the dorsal and anal fins (Roberts 1986). The snout extends into a proboscis with anterior nostrils on each side; there are no pelvic fins (Kottelat 2001). The body has a pattern of well-developed reticulated dark markings that extend over the entire body and completely encircle the belly (Roberts 1986, Rainboth 1996). The pale areas in the network are often bright yellow, especially on the abdomen (Roberts 1986).

Size: to 70 cm standard length (Rainboth 1996)

Native Range: This species is native to the freshwaters of Thailand, Lao People's Democratic Republic, Cambodia, Vietnam, and Peninsular Malaysia (Jamaluddin et al. 2019).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: This species is usually found in flowing water over gravel substrates (Rainboth 1996). It buries or hides in sheltered spots created by rocks, wood, and submerged vegetative debris (Lim et al. 1990, Jamaluddin et al. 2019). This species is nocturnal and feeds on benthic insect larvae, worms, and some plant matter (Rainboth 1996).

Means of Introduction: likely aquarium release

Status: Unknown

Impact of Introduction: The impact of this species is currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

References: (click for full references)

Jamaluddin, J.A.F., N. So, B.M. Tam, A. Ahmad, C. Grudpan, L.M. Page, M.Z. Khaironizam, and S.A.M. Nor. 2019. Genetic variation, demographic history and phylogeography of tire track eel, Mastacembelus favus (Synbranchiformes: Mastacembelidae) in Southeast Asia. Hydrobiologia 838:163-182.

Kottelat, M. 2001. Fishes of Laos. WHT Publications Ltd., Sri Lanka.

Lim, K.K.P., P.K.L. Ng, and M. Kottelat. 1990. On a collection of freshwater fishes from Endau-Rompin, Pahang-Johore, Peninsular Malaysia. The Raffles Bulletin of Zoology 38:31-54.

Nagao Natural Environment Foundation. 2021. Fishes of the Indochinese Mekong. Nagao Natural Environment Foundation, Tokyo, Japan.

Rainboth, W.J. 1996. Fishes of the Cambodian Mekong. FAO Species Identification Field Guide for Fishery Purposes. Food and Agriculture Organization of the United Nations, Rome.

Roberts, T.R. 1986. Systematic review of the Mastacembelidae or spiney eels of Burma and Thailand, with descriptions of two new species of Macrognathus. Japanese Journal of Ichthyology 33:95-109.

Other Resources:

Author: M.E. Brown

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.