Jay Richard Stauffer

Pennsylvania State University | Penn State · Department of Ecosystem Science and Management

Parasites are very diverse and common in both natural populations and in stocks kept in aquacultural facilities. For most cultured species, there are important bacteria and viruses causing diseases, but eukaryotic parasites are also very important. We review the various combinations of aquacultured species and eukaryotic parasitic groups and discus...

The Chesapeake logperch, Percina bimaculate (Halderman) has a disjunct distribution when compared to other species in the subgenus Percina. Members of this subgenus in Pennsylvania include Percina caprodes caprodes (Rafinesque), Percina caprodes semifasciata (DeKay), and P. bimaculata. Historically the Chesapeake logperch was known only from the Su...

The rock-dwelling cichlids from Lake Malaŵi, known as mbuna, comprise a diverse group of haplochromine fishes that are placed among 14 genera. Within the mbuna, Pseudotropheus is a polyphyletic genus, which has served as a catch-all for many of these fishes. Recently, many of the species-groups within Pseudotropheus have been elevated to separate g...

The determination of endangered species is problematic. If one considers a species to be ontological individuals, then if a species goes extinct, it is gone forever. The Brook Trout is used as an example of a “species” which may be comprised of several unique entities that warrant a specific status. In addition to determining the specific status, i...

Indigenous freshwater mussels (Unionidae) are integral to riverine ecosystems, playing a pivotal role in aquatic food webs and providing ecological services. With populations on the decline worldwide, freshwater mussels are of conservation concern. In this study, we explore the propensity of the invasive Round Goby (Neogobius melanostomus) fish to...

A marked increase in food production is necessary if the World Health Assembly goal of ending world hunger and malnutrition in all its forms by 2030 is to be achieved. To this end, aquaculture plays a major role, but it could play an even more prominent role at least in some areas, especially Africa. There is a need to further develop aquaculture b...

The Nile Tilapia, Oreochromis niloticus, is a freshwater cichlid indigenous to the tropical and subtropical parts of the eastern and western Africa and is being cultured in the Lake Malawi catchment on the Tanzanian side. Historically, the Nile Tilapia has been successful in dispersing once it has been introduced into a catchment area. The probabil...

Many diseases linked with trematodes are zoonotic, including liver flukes (Fasciola spp., Clonorchis, and Opistorchis are the most common), intestinal flukes (some species of the Heterophyidae), lung flukes (Paragonimus spp.) and the blood flukes (schistosome species). A characteristic for all these species is that they have a vertebrate as final h...

Freshwater mussels are an imperiled group of organisms that are vital to aquatic ecosystems. Services performed by freshwater mussels, coupled with their use for biomonitoring, make them an invaluable asset. Neogobius melanostomus (Round Goby), a recently introduced invasive species to the French Creek watershed, was once restricted to the watershe...

Metriaclima is the most speciose genus of rock-dwelling fishes (mbuna) found in Lake Malaŵi with 32 described species and with about 40 recognized forms that still await formal description. The genus is comprised of many geographically narrow populations restricted to specific habitat landmarks, such as reefs or islands. A few species have taken to...

Cichlids inhabiting the Great Lakes of Africa have radiated extremely rapidly, with Lake Malaŵi harboring some 850 species. This rapid radiation may be linked to the diversity in behaviors, sexual selection, and phenotypic plasticity. To determine the relationships between morphology and behaviors, microcomputed tomography (microCT) was used to obs...

The present study describes Serranochromis alvum n. sp., Serranochromis swartzi n. sp., Serranochromis cuanza n. sp., and Serranochromis cacuchi n. sp. from Angolan tributaries of the Cuanza and Okavango systems in Angola. The presence of four or five scale rows between the posterior margin of the orbit and the ascending arm of the preoperculum, th...

A species of haplochromine cichlid fish of the genus Diplotaxodon Trewavas, endemic to Lake Malaŵi is described: Diplotaxodon dentatus, new species. All eight type specimens were trawled together off Thumbi East Island in the Southeastern arm of the lake at 73 meters in 1985. They were initially identified as D. argenteus because the teeth on the o...

Serranochromis robustus robustus from Lake Malaŵi and Serranochromis robustus jallae from Zambia were compared using morphological data. We re-elevated S. robustus jallae to species based on the following. Serranochromis robustus generally has a longer lower jaw (50.7–59.6% HL) than S. jallae (49.2–52.7% HL). Serranochromis robustus is not as deep-...

Etheostoma caeruleum (Rainbow Darter) is a member of a diverse benthic insectivorous feeding guild. In streams with high diversity of fishes, niche partitioning by food items is one method for determining overall resource partitioning. The objective of this study was to gain insights into the foraging habits of Rainbow Darters, specifically in comm...

The round goby (Neogobius melanostomus) was discovered in 2013 in the French Creek (Allegheny River Drainage) watershed and is the first documented invasion outside of the Lake Erie basin in Pennsylvania. The round goby throughout the Laurentian Great Lakes is known to eat dressenid mussels (Dreissenidae), but consumption of either dressenids or na...

A new species, Metriaclima koningsi, is described from Likoma and Maingano islands in Lake Malaŵi. The species is distinguished from other congeners, except Metriaclima usisyae Li, Konings & Stauffer, by the absence of conspicuous bars along its flank and the presence of a dark submarginal band in the dorsal fin. Males of M. usisyae have gold colou...

Two species of haplochromine cichlid fishes of the genus Diplotaxodon Trewavas, endemic to Lake Malaŵi are described: Diplotaxodon longimaxilla, new species, and Diplotaxodon altus, new species. Diplotaxodon altus is diagnosed from other species in the genus based on body depth (35.1-37.8% SL), number of gill rakers (21-26), and a smaller cheek dep...

The Round Goby (Neogobius melanostomus) is an invasive fish species currently found in all five of the Laurentian Great Lakes of the United States. Round gobies have previously been restricted to the Lake Erie watershed of Pennsylvania, however, in fall of 2014, they were discovered in portions of the upper Allegheny River watershed, specifically L...

The monitoring of changes in benthic macroinvertebrate communities over time facilitates the evaluation of any changes that occur in the function and structure of aquatic ecosystems. We hypothesized that it would be possible to determine, through running simulations, which trophic group of fishes' gut content can and should be used to best determin...

Within the upper Ohio River watershed, 3 Etheostoma darter species in the subgenus Nothonotus have been documented in disjunct populations and were listed as threatened or endangered in Ohio and Pennsylvania. Tailwater habitat below navigation lock and dam (L/D) installations has been shown to contain diverse darter assemblages. Etheostoma camurum...

p style="text-align: justify;">Los grandes lagos de Nicaragua, son comparables con el sistema de grandes lagos africanos. Contienen una gran diversidad de peces, incluyendo varios peces endémicos de la familia Cichlidae. La captura de peces en el Lago de Cocibolca, estandarizada en 100 metros de red, promedió 4.34 kilogramos en el área de Ometepe,...

Lake Malawi is known for its endemic haplochromine species flock, most notably the rock-dwelling cichlids known as mbuna. The group of mbuna referred to as the Pseudotropheus elongatus species group is currently comprised of Metriaclima spp., Tropheops spp., Cynotilapia spp., and Pseudotropheus spp. In this study, Chindongo, a new genus with the ty...

The relative abundance of Neogobius melanostomus (Round Goby) in the Pennsylvanian waters of Lake Erie, has increased dramatically since 1996. Associated with this increase, all benthic species in the main portion of the lake, except Percopsis omiscomaycus (Trout-perch), decreased in occurrence or were extirpated. Proterorhinus semilunaris (Tubenos...

Pseudotropheus livingstonii and P. elegans are two sand-dwelling cichlid species that belong to the so-called mbuna, a group of predominantly rock-dwelling haplochromines of Lake Malaŵi. The identity of these two species has confused taxonomists for almost a century until a recent rediscovery of representatives of P. elegans close to its type local...

Water withdrawals in the Susquehanna River basin, USA, are increasing due to burgeoning shale gas extraction activities. In order to determine if flow alteration resulting from shale gas industry surface water withdrawals impacts fish and macroinvertebrate assemblages in lotic habitats, data were collected upstream and downstream of 12 withdrawal a...

The taxonomic status of Salvelinus fontinalis (Mitchill) is problematic. Difficulties in comparison of populations are exacerbated by the lack of type material. Here we designate a neotype from Connetquot River, Long Island, New York. We provide genetic and morphological data for the neotype, conspecifics, and other populations (Swan Creek, Nissequ...

Native populations of lampreys are declining throughout the Great Lakes drainage basin due to habitat loss and degradation, anthropogenic stresses, and stream treatment with lampricides to control the exotic Petromyzon marinus (Sea Lamprey). We surveyed 19 streams across Pennsylvania to determine the presence/absence of six species that were histor...

Given that both neutral drift and natural selection govern the variance of traits among demographically distinct entities, we are employing a research framework that involves quantifying neutral (i.e., differentiation due to genetic distance) and adaptive genetic variation (measured by mass gene expression profiling) among ecologically and evolutio...

Recent development of ultra-high throughput sequencing technologies can produce epic numbers of DNA sequence reads at an affordable cost, and has boosted the number and scope of DNA sequencing projects. Actual application of such tools has lagged significantly behind technical advances, and relatively few examples exist of genome-scale methods that...

Multiple anthropogenic environmental stressors with reinforcing effects to the deterioration of ecosystem stability can obscure links between ecosystem change and the prevalence of infectious diseases. Incomplete understanding may lead to ineffective public health and disease control strategies, as appears to be the case with increased urogenital s...

Although dams are a common feature on rivers throughout the world, their effects on diversity, composition, and structure of fish assemblages are often unclear. We used electrified benthic trawls and stable isotope analysis of δ13C and δ15N to determine the complex relationships between taxonomic diversity and food web structure of fish assemblages...

Fish raised in aquaculture ponds may get infected with fishborne zoonotic trematodes (FZT) during the nursing stage. Freshwater snails serve as intermediate hosts for FZT and we wanted to explore the possibility of controlling snails by stocking nursery ponds with a few juvenile specimens of the mollusceating fish, black carp (Mylopharyngodon piceus)...

We characterized variation within the mitochondrial genomes of the invasive silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) from the Mississippi River drainage by mapping our Next-Generation sequences to their publicly available genomes. Variant detection resulted in 338 single-nucleotide polymorphisms for H. molitrix and 39...

Erratum to: Conservation Genet Resour DOI 10.1007/s12686-014-0296-3In the original publication, the author’s funding information was inadvertently omitted. The missing funding information in the acknowledgement section should read as “Partial funding for this document is provided by Great Lakes Restoration Initiative Program grant Award #F12AP01160...

For the last 15 years, we have studied the relationships among cichlid snail-eating fishes, intermediate snail-host density, and the prevalence of human infection of Schistosoma haematobium in Lake Malaŵi and concluded that the increase of human infection is correlated with the decrease in snail-eating fishes in the shallow waters of the lake. We p...

While the current paradigm for conservation of species and associated habitats places emphasis on recognition and protection of irreplaceable evolutionarily distinct lineages, the identification of adaptive features must become a priority and may best be protected by maintaining evolutionary potential in the form of heterogeneous landscapes, migrat...

The black carp, Mylopharyngodon piceus, is used for biological control of freshwater mollusks in various parts of the World. Fish-borne zoonotic trematodes (FZTs) are a public health concern in Vietnam and we suggest using black carp in nursery ponds, which are important for FZT transmission, to control snails serving as first intermediate hosts. H...

Background The risks of fish-borne zoonotic trematodes (FZT) to human health constitute an important problem in Vietnam. The infection of humans with these trematodes, such as small liver trematodes (Clonorchis sinensis and Opisthorchis viverrini), intestinal trematodes (Heterophyidae) and others is often thought to be linked to fish culture in are...

Lake Malawi is known for its endemic haplochromine species flock, most notably the rock-dwelling cichlids known as mbuna. One of the larger genera of mbuna is Metriaclima, a group consisting of 31 described species (including the five described herein) and approximately 45 recognized unique populations. Metriaclima is diagnosed by its feeding behav...

1. Human activities affect fish assemblages in a variety of ways. Large‐scale and long‐term disturbances such as in‐stream dredging and mining alter habitat and hydrodynamic characteristics within rivers which can, in turn, alter fish distribution. Habitat heterogeneity is decreased as the natural riffle–pool–run sequences are lost to continuous po...

The melon fruit fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), is one of the important insect pests of fruits and vegetables. In order to monitor and control it effectively, it is necessary to know the potential geographical distribution of this pest. The ER (Eclosion rate) model was constructed from empirical biological data, and an...

Trematocranus placodon, a predator of freshwater snails in Lake Malaŵi, has been recommended for the control of schistosome intermediate hosts in aquaculture ponds. Fish from Lake Malaŵi were introduced into a pond close to Lilongwe and we attempted to elucidate whether pond-raised F1 retain their ability to consume snails. In laboratory experiment...

The Lake Malawi genus Melanochromis included five species at its inception and was originally distinguished from Pseudotropheus on the basis of morphology, including the arrangement of teeth on the lower pharyngeal bone. The diagnosis has been extended twice, first to include all elongate mbuna that possess horizontal stripes and U-shaped tooth ban...

There is evidence that transmission of Schistosoma haematobium has increased in some areas in the southern part of Lake Malaŵi, where transmission occurs both along open shorelines and at inland sites. Transmission along open shores in the lake is via Bulinus nyassanus as intermediate host. Although the snail is rarely seen on top of the sediment,...

Metriaclima lanisticola (a native cichlid of Lake Malaŵi) was studied under laboratory conditions to evaluate its potential as an agent for the biological control of schistosome intermediate host snails (i.e., Bulinus globosus, Bulinus nyassanus, and Bulinus tropicus). Crushing resistance of the three snail species was evaluated. M. lanisticola ora...

Species of Stigmatochomis are haplochromine cichlids endemic to Lake Malawi, and the genus currently includes four species, S. woodi (type species), S. modestus, S. pholidophorus, and S. pleurospilus. The latter two are known from only their holotypes. Herein, we describe two additional species, Stigmatochromis macrorhynchos and Stigmatochromis mel...

Resource managers must plan for an evolutionary future for trust species, as such, ecological and evolutionary processes—those that maintain genetic diversity and provide the raw material for evolution and adaptation of populations—must be explicitly identified. Contemporary genomic technology offers great promise for exploring the mechanistic basi...

From the mid-1980s, we recorded a significant increase in urinary schistosomiasis infection rate and transmission among inhabitants of lakeshore communities in the southern part of Lake Malaŵi, particularly on Nankumba peninsula in Mangochi District. We suggested that the increase was due to over-fishing, which reduced the density of snail-eating f...

Most rocky shores of Lake Malawi harbor three different members of Petrotilapia, each one occurring in its own preferred habitat. None of the known species of Petrotilapia has a lake-wide distribution and similar habitats at separate localities harbor sometimes different species. The relationship between the members of each of the three groups is n...

Historically, open shorelines of Lake Malaŵi were free from schistosome, Schistosoma haematobium, transmission, but this changed in the mid-1980s, possibly as a result of over-fishing reducing density of molluscivore fishes. Very little information is available on schistosome infections among people in lake-shore communities and therefore we decide...

Selected temperatures increased for 15 fish species in a laboratory gradient when acclimated to 3 °C increments from 12 to 27 °C. Temperature preferences exceeded acclimation temperatures between 12 to 27 °C for all except the telescope shiner (Notropis telescopus), yellow perch (Perca flavescens), rainbow trout (Salmo gairdneri), brown trout (Salm...

Temperature preference tests were conducted on freshwater white perch (Morone americana) collected from Albemarle Sound, N.C.; Wicomico River, Md.; and Mullica River, N.J. Collection temperatures for each population were 25 °C (±2 °C) and acclimation temperatures used in temperature preference tests were 6, 12, 18, 24, 30, and 33 °C. Analysis of co...

Embryos of oviparous organisms are exposed to contaminants by two pathways: contaminant uptake from the surrounding environment, and the transfer from female to offspring (maternal transfer). The initial source of contaminant exposure for most embryos is likely to be maternal transfer; therefore, maternal transfer studies are critical in determinin...

An increase in human urinary schistosome transmission in southern Lake Malaŵi has been suggested to be associated with decreased density of molluscivorous fishes due to illegal seine-net fishing from the shore. In addition, the increased density of snails (Melanoides spp.) through the invasion of an Asian morph could have changed the predators’ pre...

Five new species of rock-dwelling cichlids from Lake Malaŵi are described. All five species phenotypically resemble Me-triaclima aurora based on the absence of a black band in the dorsal fin and occupying the rock-sand interface of the lake. Differences in overall shape, meristics, and coloration distinguish these new species from each other and fr...

Bulinus nyassanus, endemic to Lake Malawi, is an intermediate host for Schistosoma haematobium and plays an important role in transmission of this parasite along some shorelines on the Nankumba Peninsula in the southern part of the lake. Density of B. nyassanus in shallow water is usually low from January to April and a major population increase ta...

We studied larval and young-of-year fish distribution in the Ohio River within Pennsylvania for a baseline study sponsored by the U.S. Army Corps of Engineers. Fish were collected from the uppermost four pools of the Ohio River using trawls, meter nets, dip-nets, seines with 800µm mesh, and light-traps (usually used in lentic habitats). At the Corp...

Anthropogenic disturbances such as riverine gravel dredging and the construction of dams can alter hydrodynamics and nutrient flow within rivers, but their potential roles in shaping fish communities are not fully understood. We used species richness and diversity matrices as well as stable isotope analysis of δ13C and δ15N to quantify differences...

Competition with brown trout is one factor associated with the reduction of wild brook trout populations in some Pennsylvania streams. Previous research showed a correlation between pH and the distribution of brook trout and brown trout in these streams. Our goal was to determine if these species were capable of short term acclimation to low pH. Gr...

The Allegheny River contains the most diverse and unique fish assemblage in the state of Pennsylvania. The source of these fishes is through connections with surrounding drainages at different points throughout its geologic history. Sampling records are outdated and there are large portions of the Allegheny River that have not been sampled. Samplin...

Tramatocranus placodon is a facultative molluscivore endemic to the Lake Malaŵi catchment basin, Malaŵi, Africa. T. placodon feeds on both Bulinus nyassanus, which is a host of human urinary schistosomes, and Melanoides spp. in the open waters of Lake Malaŵi. We found that there was a dietary shift from insects and small snails to larger snails as...

Two species belonging to the Amphilophus citrinellus (Günther, 1864) species complex endemic to Lake Apoyo, Nicaragua are described. Both species exhibit unique phenotypic characters that have not been found in other members of the species complex. Furthermore, they breed assortatively in Lake Apoyo and can readily be distinguished in the field fro...

Bagrus meridionalis (Bagridae; locally called Kampango) Is a large substrate-spawning catfish endemic to Lake Malawi that exhibits bi-parental care and spawns primarily In the wet season from January to March. The female feeds her young trophic (unfertilized) eggs; the male orally collects offsite benthic organisms, which he brings back to feed the...

Background/Question/Methods The structure of animal communities can be assessed using a variety of ecological indices, such as measures of diversity and evenness. Meanwhile, stable isotope analysis is increasingly being used to provide information about the environment and to answer ecological questions. One of the more common ecological applicati...

Sampling small benthic and lithophilic fish species in large rivers and lakes presents challenges not adequately addressed by conventional survey methods such as boat electrofishing and gill netting. The development of the Missouri trawl has helped to address these issues; however, our observations by scuba diving when using the Missouri trawl have...

Six different populations of the Lake Malawi cave-dweller Otopharynx lithobates, each of them distinguished by differences in the male breeding coloration, were examined. We found that morphometric and meristic data of all populations overlap, and that no significant differences could be found to distinguish them. Morphological data of Otopharynx w...

The Lake Malaŵi genus Melanochromis included five species at its inception and was originally distinguished from Pseudotropheus on the basis of morphology including the arrangement of pharyngeal teeth. The diagnosis has been extended twice, first to include all elongate mbuna that possess horizontal stripes and U-shaped tooth bands and later to exc...

A new species of Petrotilapia from the Nkhata Bay region of Lake Malaŵi is described. The black submarginal band in the dorsal fin distinguishes it from Petrotilapia tridentiger Trewavas and Petrotilapia chrysos Stauffer & van Snik, which lack this band. The bright blue color of the males distinguishes it from males of Petrotilapia genalutea Marsh,...

Three new species of the Amphilophus citrinellus (Günther) species complex that are endemic to Lake Apoyo, Nicaragua are described. The new species differ from previously described members of this complex in other lakes, are phenotypically distinct, and assortatively mate in Lake Apoyo. The presence of endemic cichlids in each of the crater lakes s...

Etheostoma zonale, the banded darter, was introduced to the Susquehanna River basin of Pennsylvania through an interbasin transfer, or transplantation of native fishes outside their natural range. We examined the habitat use of a darter native to the Susquehanna River drainage E. olmstedi, the tessellated darter, in sympatry and allopatry with E. z...

We successfully artificially cultured and bred Bulinus nyassanus, endemic to Lake Malawi and an intermediate host of Schistosoma haematobium. The laboratory culture of this snail species is essential in relation to further experiments on the feasibility of using facultative snail-eating fishes as biological control agents for intermediate hosts of...

Metriaclima lanisticola, a native cichlid of Lake Malawi, was studied under laboratory conditions to evaluate its possible role as a predator of snails (Bulinus spp.). Bulinus globosus, B. nyassanus and B. tropicus were used as prey. B. globosus and B. nyassanus are intermediate hosts of human schistosomes in Lake Malawi. M. lanisticola orally shel...

Sex reversal in the Lake Malawi cichlid, Metriaclima cf. livingstoni, was documented. A functional male in an aquarium was separated from three functional females by a divider of clear Plexiglas (R) sealed to tank walls. After the male was removed, one of the functional females developed male secondary sexual characteristics and fertilized eggs pro...

Intermediate hosts of Schistosoma haematobium, the causative agent of urinary schistosomiasis, in Lake Malaŵi include: Bulinus globosus, a member of the B. africanus group and B. nyassanus, a diploid member of the B. truncatus/tropicus species complex. We compared genetic variability between isolates of S. haematobium from the southern part of the...

SummaryA biomonitoring system interfaced with a microcomputer was used to monitor ventilation rates for white perch (Morone americana) and spot (Leiostomus xanthurus) under baseline and stressed conditions caused by strobe lights. Tests were conducted on light- and dark-acclimated specimens. These two estuarine species have been found to exhibit av...