«Annotated checklist of the freshwater fishes of continental and insular Honduras WILFREDO A. MATAMOROS1, JACOB F. SCHAEFER2 & BRIAN R. KREISER2 1 ...»
ISSN 1175-5326 (print edition)
Zootaxa 2307: 1–38 (2009)
Copyright © 2009 · Magnolia Press ISSN 1175-5334 (online edition)
Annotated checklist of the freshwater fishes of continental and insular Honduras
WILFREDO A. MATAMOROS1, JACOB F. SCHAEFER2 & BRIAN R. KREISER2
Department of Biological Sciences, The University of Southern Mississippi, 118 College Dr. Box 5018, Hattiesburg, MS 39406, U.S.A., Instituto Regional para la Biodiversidad. Escuela Agrícola Panamericana El Zamorano, El Zamorano, Francisco Morazán, Honduras. E-mail: firstname.lastname@example.org 2 Department of Biological Sciences, The University of Southern Mississippi, 118 College Dr. Box 5018, Hattiesburg, MS 39406, U.S.A.
E-mail: email@example.com, firstname.lastname@example.org Table of contents
Materials and methods
Results and discussion
Accepted by L. Page: 9 Nov. 2009; published: 9 Dec. 2009 1 Abstract The freshwater fishes of Honduras were surveyed for a period of four years (2005–2008). Surveys were supplemented with both literature and museum collection reviews. Our results show that there are at least 172 species of fishes inhabiting Honduran mainland and insular freshwater systems, 166 native and six exotic. Primary freshwater fish diversity was low, with only eigth species (4.8%). The remaining species were either secondary freshwater (47 species, 28.3%) or peripheral (111 species, 66.9%). This checklist includes 36 new records for Honduras, and 12 range expansions. Nine species were found to be endemic; however, just two of them (Amphilophus hogaboomorum and Theraps wesseli) are already described. The depauperate primary freshwater fishes fauna of Honduras (8) is congruent with low primary freshwater fishes diversity found in the region between the Usumacinta River and the Nicaraguan great lakes. Although many previously unsampled regions of Honduras were visited as part of this project, there are a variety of remote areas that remain unstudied. While this paper contributes much to the understanding of the distribution and diversity of Honduran freshwater fishes, it is likely that much diversity there remains undocumented.
Key words: Central America, Nuclear Middle America, Obligate freshwater fishes, Primary freshwater fishes, Distribution, Ichthyofauna, Fish fauna, Biodiversity Resumen Los peces de agua dulce de Honduras fueron estudiados por un periodo de cuatro años (2005 a 2008). Los muestreos de campo fueron complementados con revisiones tanto de colecciones de museos como de la literatura disponible. Nuestros resultados muestran la presencia de 172 especies de peces que habitan los sistemas de aguas continentales del país y de sus islas, de ellas 166 son nativas y seis exóticas. La diversidad de peces primarios de ambientes dulceacuícolas fue baja, con tan solo ocho especies (4.8%) presentes. El resto fueron secundarias (47 especies, 28.3%) o periféricas (111 especies, 66.9%). Esta lista incluye 36 registros nuevos para Honduras y 12 expansiones de rango geográfico. Nueve especies fueron reportadas como endémicas; sin embargo solamente dos (Amphilophus hogaboomorum y Theraps wesseli) son consideradas especies válidas. La descripción de las ocho especies restantes está aún pendiente. El bajo número de especies primarias dulceacuícolas (8) en Honduras coincide con el bajo número de especies primarias reportadas anteriormente en la región entre el río Usumacinta y los grandes lagos de Nicaragua. Aunque muchas regiones de Honduras que no habían sido previamente muestreadas fueron visitadas como parte de este proyecto, todavía hay áreas remotas del país que precisan ser estudiadas. Este trabajo contribuirá extensamente al entendimiento de la distribución y diversidad de los peces de agua dulce de Honduras; sin embargo, mucha de la diversidad ictiológica del país requiere aún ser investigada con mayor profundidad.
2 · Zootaxa 2307 © 2009 Magnolia Press MATAMOROS ET AL.
Introduction The diversity and distributional patterns of Honduran freshwater fishes are the product of recent geological events (Myers, 1966). All primary and secondary freshwater species that inhabit Honduras are of South American origin (Miller, 1966, Myers, 1966), moving to the region during or after the raising and closure of the Isthmus of Panama during the Pliocene (Marshall et al., 1979, Stehli & Webb, 1985). The proposed timing of the enclosure of the Panamanian isthmus varies from between 3.1 to 3.5 million years ago (Coates et al., 1992, Coates & Obando, 1996) to as early as 1.8 million years ago (Keller et al., 1989). While the formation of this land bridge is often cited as the major event structuring Honduran freshwater fish diversity, local geologic, climatic and other factors have also certainly played a role (Savage, 1982). Unfortunately, few attempts have been made at studying Honduran freshwater fish biodiversity on a scale adequate to assess the role of local vs. regional processes in structuring biogeographic patterns in the country. As a result, Honduras (Fig. 1) has long represented a large gap in biogeographical knowledge of Central America fishes (Carr and Giovannoli, 1950, Miller, 1966, Lyons, 2005).
Accordingly, as a baseline for future biogeographical studies, we present an updated checklist of the freshwater fishes of Honduras that has been compiled from: 1) field sampling of all major drainages, 2) data from published literature and 3) review of museum holdings from Honduras. Checklists like this are an important tool for researchers, governmental and non-governmental agencies with interest in documenting and conserving biodiversity. It will serve as a foundation for future research aimed at understanding the origin and status of Honduran fish diversity as well as effective management and conservation programs (McNeely et al., 1990).
Review of freshwater ichthyographical research in Honduras Most of what is known about Honduran ichthyology is based on work done at a larger regional scale.
Distributional ranges of freshwater fishes that included the territory of Honduras were mentioned in the works of Jordan & Evermann (1896–1900), Regan (1906–1908), and Jordan et al. (1930). These publications analyzed the freshwater ichthyofauna of Central America in general. However, sampling in Honduras was almost non-existent at the time. In his work with cyprinodonts, Hubbs (1924, 1926 and 1931) mentioned a number of Honduran collections containing Phallichthys amates, Belonesox belizanus, and Alfaro huberi.
Fowler (1932) reported collections in the Lancetilla and Choluteca Rivers. Rehn (1932) reported some collections in the Honduran Mosquitia region. Strong (1934) reported a bull shark (Carcharhinus leucas) in the Patuca River in La Mosquitia. Miller (1955) reported specimens of Profundulus guatemalensis collected in 1934 by A. Greenberg in western Honduras. Fowler (1943) reported collections made by G. Orr in Islas de la Bahía, and described Poecilia orri with specimens collected in the island of Bonnaca. The first detailed sampling of rivers in the country was carried out by A. Carr in the late 1940’s. Carr focused on rivers of the Honduran Pacific slope, culminating with an analysis of the fishes of the Choluteca River and the description of Amphilophus hogaboomorum (Carr & Giovannoli, 1950). Carr also published a second paper on the distribution and systematic relationships of some freshwater fishes of the Honduran and Nicaraguan Mosquitia region (Miller & Carr, 1974).
The overall structure of Central American ichthyographical provinces was first proposed by Miller (1966). He proposed that Honduras was part of the Chiapas-Nicaraguan Province that extends from southern México to southern Nicaragua. Miller (1966) did not suggest separate provinces for the Honduran and Nicaraguan Atlantic slope, arguing there was not enough information available for that part of Central America. Ten years later, however, Bussing (1976), proposed a second additional ichthyographical province for Honduras: the Usumacinta province on the Honduran Atlantic slope. This province extends from the Usumacinta River in southern México to northern Nicaragua. From 1968 to 1970, Martin (1972) intensively sampled parts of Honduras as part of an unpublished thesis. For the next two decades, there were no major collections conducted on Honduran freshwaters fishes. In 1996, Theraps wesseli was described from
Geological history The region of Nuclear Central America that corresponds to Honduras has a complex geological history characterized by intensive faulting, orogeny, sea level change, sedimentation, and volcanism. The land connection between North and South America was lost in the early Jurassic as Pangaea broke apart (Dietz & Holden, 1970). It is widely accepted that no land connection existed between North and South America from the early Cretaceous to the Pliocene (Holden & Dietz, 1972; Malfait & Dinkelman, 1972; Ladd, 1976;
Duellman, 1979; Savage, 1982). However, parts of Nuclear Central America, including the majority of Honduras, may have been above water since the Cretaceous (Savage, 1982). A faunal exchange between México and Nuclear Central America through the Isthmus of Tehuantepec happened during the Tertiary (Olson & McGrew, 1941). This faunal exchange was facilitated by a climatic filter barrier and a probable partial sea barrier across the Isthmus (Savage, 1982). The Miocene was characterized by intensive faulting in the area, which produced several graben valleys, including the Honduras depression that is a corridor from the Caribbean to the Pacific slope (Roberts & Irving, 1957). During the Miocene – Pliocene intense volcanism occurred in the area (Roberts & Irving, 1957). Intense orogeny during late Pliocene or early Pleistocene formed the terrace systems of interior Honduras. Much of the Caribbean lowlands emerged during the Pleistocene as a result of extensive erosion and deposition in alluvial lowland depressions. There were also hypothesized fluctuations in sea level and climate during the Pleistocene glaciations (Roberts & Irving, 1957).
The uplifting of the Isthmus of Panama during the mid-Pliocene created the land bridge connecting North and South America (Beu, 2001). This facilitated a massive faunal migration from both continents, referred to as the Great American Biotic Interchange (Marshall et al., 1979; Stehli & Webb, 1985).
Although there are no currently active volcanoes in Honduras, volcanism has shaped the physiographic features of the country. Volcanic activity in Nuclear Central America was widespread during the Miocene and Pliocene, which resulted in the deposition of andesitic and rhyolitic ejecta over the majority of the southern half of Honduras (Roberts & Irving, 1957). The rough terrain in this region was largely created during the Oligocene (the Sierras Madre in México), Miocene (highlands of Nuclear Central America) and Pliocene (highlands of Lower Central America including the Comayagua Graben) (Roberts & Irving, 1957;
Maldonado-Koerdell, 1964; Savage, 1982). The Gulf of Fonseca was formed by downfaulting at the Comayagua Graben and the Nicaraguan Graben (West, 1964). Finally, Islas de la Bahía on the Honduran Caribbean coast (Fig. 1) appear to be a northward extension of the Sierra de Omoa and were apparently connected to the mainland throughout most of the middle and late Tertiary (Vinson & Brineman, 1963).
Physiography A physiographical region is defined as a geographic area with similar geologic, topographic, and edaphic features (West, 1964). Subdivisions of these physiographic regions are called sub-regions, in which there is a general uniformity of surface features (Martin, 1972). There are three major physiographic regions proposed for Honduras (Bengston, 1926; Carr, 1950; Martin, 1972): the Pacific Lowlands, the Caribbean Lowlands, and the Interior Serranía Region. The Pacific Lowlands region does not contain any sub-regions, but includes the river basins that drain into the Gulf of Fonseca (Bengston, 1926; Carr 1950). This includes the Goascorán, Nacaome, Choluteca, and Negro rivers (Fig. 2). The Caribbean Lowlands extend from the delta of the Motagua River in western Honduras to the Coco River bordering Nicaragua. The Caribbean lowlands are divided into five sub-regions (Bengston 1926; Carr 1950); the Motagua River Delta, the Ulúa-Chamelecón River Valley, the Nombre de Dios Plain, the Aguán-Negro River Plain, and the Mosquitia Coast (Fig. 2). The Interior Serrania Region is formed by the Northern Cordillera and the Southern Cordillera sub-regions.
Detailed description of Honduran physiographic regions and sub-regions are found in Bengston (1926), Carr (1950), Martin (1972), Wilson & Meyer (1985) and McCraine & Wilson (1985).
Materials and methods Institutional abbreviations are as follows: CAS = California Academy of Sciences; FLMNH = Florida Museum of Natural History; FMNH = Field Museum of Natural History; GCRL = Gulf Coast Research Laboratory; LACM = Los Angeles County Museum; UMMZ = University of Michigan Museum of Zoology;
USM = University of Southern Mississippi Museum of Ichthyology; USNM = United States National Museum.