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Project Work Plan

Department of Interior USGS GE PES
Fiscal Year 2014 Study Work Plan

TITLE: Nonindigenous Fishes in Florida: A Guide to their Identification, Distribution, Ecology, and Impacts
PRINICIPAL INVESTIGATORs: Leo G. Nico and Howard Jelks
Principle Investigator CONTACT INFORMATION:
USGS Southeast Ecological Science Center, 7920 NW 71st Street, Gainesville, Florida 32653, USA; Email:; ph: 352-264-3501; FAX: 352-378-4956

STATEMENT OF PROBLEM: As many as 38 different introduced non-native fish species have established reproducing populations in the state of Florida. Some, such as tilapias and armored suckermouth catfishes, are considered highly invasive. Most of Florida's nonindigenous fishes are present and widespread in South Florida and the Greater Everglades, a region of the world considered a "hot spot" for invasive fishes. In many South Florida habitats, including certain lakes and parts of streams and canals, the biomass and relative numbers of nonindigenous fish are greater than those of the native fish fauna present.

The 38 established nonindigenous fishes in Florida are a diverse group that includes members of 13 different fish families. They originate from many parts of the globe, including species from Central and South America, Africa, Asia, and Europe. Some of the nonindigenous fish species in Florida are tropical and others from temperate climates. Most primarily inhabit fresh water, but others are euryhaline and able to survive and/or reproduce in fresh, brackish and marine environments. A few species are strictly marine. Several of the nonindigenous species in the state are air-breathing fish (e.g., Asian swamp eels, loricariid and clariid catfishes) and able to persist in habitats nearly devoid of dissolved oxygen. Body size ranges from the guppy (Poecilia reticulata), with adult males typically < 2.5 cm total length, to the grass carp (Ctenopharyngodon idella), which grow to over one meter. Nearly all major trophic levels are represented, including small and large herbivores, omnivores, and predators.

Positive identification of introduced fishes is often difficult for many reasons. Some fish groups have unresolved taxonomy and unstable nomenclature. The adults or juveniles of certain nonindigenous fishes are similar in appearance to some of our native fish species leading to misidentifications even by biologists. Certain taxa, such as the tilapias and many fishes in the aquarium trade, are particularly problematic because of frequent hybridization in captivity and in the wild, as well as the creation of new strains by aquaculture researchers. Consequently, those introduced into the wild frequently exhibit unique coloration patterns, traits originally developed artificially in captive populations to enhance marketability. Ichthyologists periodically re-examine non-native fish specimens and, in some cases, have corrected previous misidentifications. Consequently, some names appearing in past publications are no longer valid. Consequently, some species long thought to be established in the state are actually a different species, and a few "individual species" are now known or suspected of being composed of multiple species, including some forms possibly not yet known to science. The situation is also highly dynamic. Over the past ten years, several additional nonindigenous fish species have been reported as newly established in the state.

Information for identification of nonindigenous species that is easy-to-use and up-to-date is essential for agencies to detect, track, manage and control invasive species. Effective control and management measures can only be implemented when nonindigenous species are correctly and promptly identified. Misidentifications can cost money when rapid decisions need to be taken. In the case of Florida's nonindigenous fishes, rapid identification of captured fish allows authorities to verify whether it is non-native and also determine if the fish is new to the state or a particular region in the state, perhaps providing sufficient advance detection for effective containment or even eradication. Positive identification is necessary to track and assess changes in the geographic distribution of nonindigenous species. Since related species may have very different attributes (e.g., temperature or salinity tolerances) and ecological impacts, it is important to positively identify species so as to properly understand the risks of an introduction.

Although nonindigenous fishes found in Florida have received increased attention, there is no single publication that provides for identification of all 38 of the nonindigenous fish present in the Greater Everglades region or other parts of the state. Neither is there a single source that provides up-to-date information on their geographic distributions, ecology, life histories, impacts, and management/control options for each of these species

OBJECTIVES: The objective of the project is to prepare an electronic identification guide to the nonindigenous fishes of the Greater Everglades and Florida. The guide will be openly available via a USGS website, accessible for use in both the field and laboratory. It will include dichotomous keys and browsable illustrated guides to the nonindigenous species with a variety of additional information useful for positive identification of each species. The final product will also document what is known about each species's introduction, dispersal, and current distribution, and discuss important aspects of their ecology, life history, and environmental effects. Heavy emphasis will be placed on the non-native fishes established in the Greater Everglades. The resulting guide is expected to be useful to a wide range of users, including aquatic biologists and other scientists, natural resource managers, and members of the general public interested in invasive species and devoted to understanding, protecting, and restoring the Everglades and other ecosystems within the region.

Preliminary Work Completed: Over the past ten years, we have done a substantial amount of preliminary work. To date, we have: sampled most drainages in the state; collected and taken high-quality photographs of the juvenile and adult stages of most of the cichlids and a few other nonindigenous fish species present; examined and recorded morphological data on representative specimens of many of the species so as to document characteristics useful for identification; begun preparing identification keys and species accounts; and started constructing species-distribution maps.

METHODOLOGY: Most work on the project will be conducted at the SESC's facility (i.e., laboratory and office areas) in Gainesville. Work at the facility will initially involve examination of preserved material and selecting useable photographs already present at the SESC facility so as to record information on fish color patterns and external anatomy. Focus will be on documenting unique character variables useful in distinguishing one species from another (e.g., general body shape; position of mouth; size and location of fins; size, number, and shape of teeth; presence/absence of barbels, spines, and scales). In some cases where there is known ontogenetic differences, it will be necessary to carefully document intraspecific differences among adults versus juveniles. Information from the examination of specimens and review of the literature will then be used to create a data matrix of species x character combinations, where rows of the matrix represent species and the columns represent characters (i.e., color and anatomical information for each of the 38+ non-native fish species known to be present in Florida waters). The resulting data matrix will then be used to construct a morphogical dichotomous key and identification guides to the different species. To increase user friendliness, the identification key will rely heavily on clearly observable characteristics and be supplemented with original line drawings and color photographs displaying whole specimens or distinctive anatomical characteristics. For those non-native species similar in appearance to certain Florida native fish species, information will be included to distinguish them. Common and scientific names used in the guide will follow recommendations of the American Fisheries Society Special Publication 34 published in 2013. Visits to area museums or some minor field work may be required to obtain specimens of important species not already available at the SESC facility.

WORK PLAN: Phase 1 will be completed in FY 14. If funded, Phase 2 to be completed in FY 15, Phase 3 in FY 16. The major work tasks and major elements of the tasks are as follows:

Phase 1 (FY 14)

Task 1: Create and populate data matrix. This will involve: review of the scientific and technical literature on non-native fishes; retrieving data from existing sources; and examination of specimens and photographs currently available at SESC.

Task 2: Construct and finalize dichotomous key to the 38+ non-native fish species known to be established in inland waters of Florida. This will involve assembling appropriate photographs and line drawings to be included with the key. Prior to finalization, the dichotomous key will be tested. Following testing, the dichotomous key and associated illustrations will be made available in electronic format on the internet.

Phase 2 (FY 15)

Task 3: Prepare basic identification guides for each of the 38+ non-native fish species. Each guide will include a photograph and/or line drawing of the whole fish, summary of distinguishing morphological characteristics, and summary of the species' known geographic distribution in Florida.

Phase 3 (FY 16)

Task 5: Prepare detailed accounts for each of the 38+ non-native fish species. Each account will include information on the introduction history of the species, up-to-date information on their geographic distributions, ecology, life histories, impacts, and management/control options.

Task 6: The dichotomous keys and guides will be combined into a single document and made available in electronic format on the internet.


Phase 1: Identification keys to the 38+ species of nonindigenous fishes established in inland waters of Florida. The keys will be made available electronically on the internet

Phase 2: A field/laboratory guide published electronically on the internet containing fish species identification keys, color photographs, descriptive text and other information useful for the positive identification of the 38+ non-native fish species known to be established in Florida, with emphasis on those species present in the Greater Everglades.

Phase 3: Expansion of the product described in Phase 2, with the addition of up-to-date distribution maps for each species, written accounts for each species that will include detailed information on the ecology, life histories, impacts, and management/control options for each fish species.

RELEVANCE AND BENEFITS: The project addresses important concerns identified by the USGS's Priority Ecosystems Science (PES) Greater Everglades study unit by providing sound, relevant and timely information pertinent for the restoration, preservation, and protection of the South Florida ecosystem (see: The provided information is expected to address needs of decision-makers and meet Department of the Interior's responsibilities to manage the Nation's lands. In addition, the project meets the goals of the Invasive Species Program and the program's Five-Year Strategic Plan (refer to, helping the Department of the Interior managers and the Nation respond more rapidly and effectively to the growing threat of invasive species in U.S. ecosystems.

COMMUNICATION PLAN, TECHNOLOGY AND INFORMATION TRANSFER: The information and results of this project will be openly available in the form of one or more electronic internet publications.

COOPERATORS AND PARTNERS: The USGS's Priority Ecosystems Science program is expected to fund Phase 1 of the project and may provide additional funding for Phases 2 and 3.

QUALIFICATIONS OF STUDY PERSONNEL: The principle investigators are both USGS scientists.

Leo Nico has a Ph.D. in zoology and is an expert on a wide variety of subjects dealing with invasive fishes. He has published extensively on non-native fishes, including on subjects relating to their identification, distribution, ecology, impacts, risk assessment management, and eradication. He has authored or co-authored two technical books and numerous scientific journal articles on invasive fishes. See:

Howard L. Jelks is a research fish biologist who has conducted studies on freshwater, estuarine, and coral reef fishes. He also has considerable expertise and knowledge of inland and marine non-native fishes. See:

FACILITIES, EQUIPMENT, AND STUDY AREAS: Office and laboratory facilities and equipment, and any needed field gear or supplies, will be provided by the Southeast Ecological Science Center.

ANIMAL WELFARE: This project may require collection and preservation of a few non-native fishes for purposes of positive identification and to document their occurrence and distribution. Such field work would require combination of techniques and gear, including various types of active and passive nets, traps, and electrofishing gear.

JOB HAZARD ANALYSES (JHA): Office Work, Field Work, Travel, Formaldehyde Use, Electrofishing

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Last updated: 16 April, 2015 @ 01:52 PM (KP)