A NEW SPECIES OF THELOHANELLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE GILL OF QUILLBACK, CARPIODES CYPRINUS (CYPRINIFORMES: CATOSTOMIDAE), FROM THE ARKANSAS RIVER DRAINAGE OF OKLAHOMA.

During May 2022 and again in March 2023, 5 quillbacks, Carpiodes cyprinus, were collected from the Verdigris River, Wagoner County, Oklahoma (n = 1), and the Black River, Lawrence County, Arkansas (n = 4), and their gill, gallbladder, fins, integument, musculature, and other major organs were macroscopically examined for myxozoans. Gill lamellae from the single quillback from the Verdigris River was infected with a new myxozoan, Thelohanellus oklahomaensis n. sp. Qualitative and quantitative morphological data were obtained from fresh and formalin-fixed preserved myxospores, and molecular data consisted of a 1,767 base pair sequence of the partial small subunit (SSU) ribosomal RNA gene. Phylogenetic analysis grouped T. oklahomaensis n. sp. with myxozoans known to infect North American catostomids and Eurasian cyprinids. Histological examination localized plasmodia to an intralamellar developmental site and revealed a possible vestige of a second polar capsule. Although plasmodia markedly expanded lamellae, there were no associated epithelial or inflammatory changes. Thelohanellus oklahomaensis n. sp. is the only member of the genus known to infect the gills of C. cyprinus.

A new Myxobolus (Cnidaria: Myxosporea: Myxobolidae) from the gills of the southern striped shiner, Luxilus chrysocephalus isolepis (Cypriniformes: Leuciscidae), from southwestern Arkansas, USA.

The southern striped shiner, Luxilus chrysocephalus isolepis (Hubbs & Brown) is a relatively large minnow belonging to the true minnow family Leuciscidae Bonaparte. Between May 2020 and January 2022, 55 L. c. isolepis were collected from watersheds in Montgomery (n = 6), Polk (n = 17) and Sevier (n = 32) counties, Arkansas, USA, and their gills, gallbladders, urinary bladders, fins, integument, other major organs, and musculature were examined for myxozoans. Gills of 11 (34%) individual southern striped shiners from Sevier County were infected with a new myxozoan, Myxobolus carlhubbsi n. sp. A qualitative and quantitative morphological description was based on formalin-fixed preserved myxospores, and molecular data consisted of a 1,970 base pair sequence of the partial small subunit rRNA gene from ethanol-preserved specimens. Histologically, plasmodia filled and expanded interlamellar troughs. Hyperplastic epithelial and goblet cells filled interlamellar troughs adjacent to plasmodia, but inflammatory response was limited to scattered lymphocytes. Phylogenetic analysis revealed that M. carlhubbsi n. sp. is a member of a clade of species with pyriform myxospores parasitizing North American Pogonichthyinae Girard and North American and Eurasian Leuciscinae Bonaparte. This is the first report of a myxozoan from L. c. isolepis. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:D10D71C2-2C75-4A1C-80ED-B98FF36CB509.

Pseudomurraytrema fergusoni n. sp. (Monogenea: Dactylogyridae) from gills of Pealip Redhorse, Moxostoma pisolabrum (Catostomidae) from Arkansas, USA, with a description of gill pathology.

Pseudomurraytrema fergusoni n. sp. is described from the Pealip Redhorse, Moxostoma pisolabrum from the Black River (White River drainage), Lawrence County, Arkansas, USA. This represents the second monogenean described from M. pisolabrum as well as the second species of Pseudomurraytrema reported from an Arkansas catostomid. The description includes partial 18S rRNA and 28S rRNA gene sequences (732 bp and 851 bp, respectively), helping fill a void in sequence data from North American monogeneans, particularly those in the genus Pseudomurraytrema. In addition, histopathologic changes associated with the infection resulted in severe localized pathologic lesions in gills of the host, suggesting compromise of respiratory surfaces within affected areas adjacent to the worms.

A NEW SPECIES OF MYXOBOLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE FINS OF THE WESTERN CREEK CHUBSUCKER, ERIMYZON CLAVIFORMIS (CYPRINIFORMES: CATOSTOMIDAE), FROM ARKANSAS.

Between November 2018 and December 2021, 35 juvenile and adult Western Creek Chubsuckers, Erimyzon claviformis, were collected from 5 sites in western and southern Arkansas (Ouachita and Red River drainages), and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. The fins of 12 (34%) individuals were infected with a novel species, Myxobolus stuartae n. sp. Qualitative and quantitative morphological data were obtained from formalin-fixed preserved myxospores. Molecular data from ethanol-preserved specimens consisted of a 2,028 base pair sequence of small subunit (SSU) ribosomal DNA (rDNA) from a specimen collected in Nevada County. Three other specimens from Polk County yielded partial SSU rDNA sequences that were identical to the first sequence. Phylogenetic analyses placed M. stuartae n. sp. as sister to Myxobolus bibullatus (Kudo, 1934), both clustering with other catostomid-infecting myxobolids. This is the first fin-infecting myxozoan reported from E. claviformis.

A NEW SPECIES OF MYXOBOLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE GILLS OF CREEK CHUB, SEMOTILUS ATROMACULATUS (CYPRINIFORMES: LEUCISCIDAE: PLAGIOPTERINAE), FROM THE OUACHITA DRAINAGE OF ARKANSAS.

During October and November 2021, 33 creek chubs, Semotilus atromaculatus, were collected from 3 sites in Polk County, Arkansas (Ouachita River drainage), and their gills, gallbladder, fins, integument, musculature, and other major organs were examined for myxozoans. The gills of 9 (27%) were infected with a new myxozoan, Myxobolus fountainae n. sp. Qualitative and quantitative morphological data were from fresh and formalin-fixed preserved spores, while molecular data consisted of a 1918 base pair sequence of the partial small subunit ribosomal RNA gene. Phylogenetic analysis grouped M. fountainae n. sp. with the other leuciscid-infecting myxobolids from North America and within a larger clade of European myxozoans. In addition, histological information is provided on the infection. A previous record of Myxobolus muelleriBütschli, 1882, from the gills and ureters of S. atromaculatus is considered invalid and represents an unknown species. Myxobolus fountainae n. sp. is the only named myxozoan known to infect the gill filaments of S. atromaculatus, whereas Myxobolus pendula (Guilford, 1967) infects the gill arches.

A new species of Myxidium (Cnidaria: Myxosporea: Myxidiidae) from the gallbladder of pickerels, Esox spp. (Esociformes: Esocidae), from southwestern Arkansas, USA.

During April 2016 and again in November 2021, four Chain Pickerels, Esox niger were collected from Union (n = 3) and Nevada (n = 1) counties, Arkansas, USA, and 65 Grass Pickerels, Esox americanus vermiculatus were collected between January 2015 and December 2021 from four counties of Arkansas (n = 31) and McCurtain County, Oklahoma, USA (n = 34), and examined for myxozoans. Gallbladders of an individual E. niger from Nevada County, Arkansas, as well as a single individual of E. a. vermiculatus from Sevier County, Arkansas, were infected with a new myxozoan, Myxidium whippsi n. sp. Qualitative and quantitative morphological data were from formalin-fixed preserved myxospores while molecular data (SSU rRNA gene) consisted of 2031bp (host: E. niger) and 1723 bp (host: E. a. vermiculatus) partial sequences of the small subunit ribosomal RNA gene. Phylogenetic analysis placed M. whippsi n. sp. in a clade with two other myxozoans, Zschokkella nova and Myxidium truttae, previously reported from cyprinids and salmonids, respectively. We document the first report of a myxozoan from E. a. vermiculatus. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:A50FCEB3-68C3-428E-A04E-37A16790F1EB.

A NEW SPECIES OF MYXOBOLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE BLUE SUCKER, CYCLEPTUS ELONGATUS (LESUEUR) (CYPRINIFORMES: CATOSTOMIDAE: CYCLEPTINAE), FROM ARKANSAS.

During 9-10 February 2018 and 21-22 February 2020, 7 adult Blue Suckers, Cycleptus elongatus, were collected by hoop nets from the Red River, Little River County (n = 3), and the Black River, Lawrence County (n = 4), Arkansas, and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. All 7 (100%) were infected with an unknown species of gill-infecting Myxobolus sp. Twenty formalin-fixed plasmodia (cysts) of Myxobolus cloutmani n. sp. were elliptoidal, 407 µm long × 270 µm wide. Formalin-fixed myxospores were orbicular to broadly elliptoidal, 8.7 µm long × 7.8 µm wide. Two polar capsules were pyriform and subequal in size, extending over halfway in the myxospore. The larger polar capsule was 5.5 µm long × 3.1 µm wide, while the shorter was 5.1 × 2.9 µm. A coiled polar filament possessed 5 or 6 coils. The myxospore was 3.7 µm thick in sutural view, with a distinct sutural ridge. Qualitative and quantitative morphological data were from formalin-fixed as well as ethanol-preserved spores, while molecular data consisted of a 2,010 base pair sequence of the partial 18S ribosomal RNA gene and a 2,502 base pair sequence of the partial 28S ribosomal RNA gene. Phylogenetic analysis grouped M. cloutmani n. sp. with the other catostomid-infecting myxobolids. This is the first myxozoan reported from C. elongatus.

Urocleidus sayani n. sp. (Monogenea: Dactylogyridae) from Gills of Pirate Perch (Aphredoderus sayanus).

Urocleidus sayani n. sp. is described from the gills of pirate perch (Aphredoderus sayanus) in the Wisconsin backwaters of the upper Mississippi River and was found in samples from the Southeastern United States. Urocleidus sayani n. sp. is the second monogenean described from the pirate perch and the first for this host within Dactylogyridae. The description includes a partial 18S rRNA gene sequence (623 bp), filling a void in sequence data from North American monogeneans.

Revision of monogeneans parasitising Lythrurus (Cypriniformes: Leuciscidae) in eastern U.S.A., with description of Dactylogyrus lythruri sp. n. and new records of Dactylogyrus crucis Rogers, 1967 (Monogenoidea: Dactylogyridae).

A revisionary study revealed two species of monogeneans, Dactylogyrus crucis Rogers, 1967 and Dactylogyrus lythruri sp. n., parasitising Lythrurus Jordan (formerly a subgenus of Notropis Rafinesque, 1818). New records and updated taxonomy of seven of 12 known minnows of the genus of Lythrurus are provided for D. crucis. A record of Dactylogyrus attenuatus Mizelle et Klucka, 1953 (syn. Dactylogyrus umbratilus [Kimpel, 1939], nomen nudum) on Lythrurus umbratilis (Girard) is referrable to D. crucis. Dactylogyrus lythruri is described from eight species of Lythrurus. It most closely resembles Dactylogyrus beckeri Cloutman, 1987, but is distinguished by having a smaller base of the male copulatory organ (MCO) and lacking a ventral enlargement of the distal end of the basal process. Previous reports of Dactylogyrus banghami Mizelle et Donahue, 1944 and Dactylogyrus cf. beckeri Cloutman, 1987 from Lythrurus atrapiculus (Snelson) and Lythrurus bellus (Hay) from Alabama, and Dactylogyrus confusus Mueller, 1938 from L. umbratilis in Illinois are herein relegated to D. lythruri. Four species of Lythrurus appeared not to be infected with Dactylogyrus.

Dactylogyrus pisolabrae n. sp. (Monogenoidea: Dactylogyridae) Parasitizing the Pealip Redhorse, Moxostoma pisolabrum (Teleostei: Catostomidae), from Oklahoma, U.S.A.

A new species of monogenean, Dactylogyrus pisolabrae n. sp., was found parasitizing the gills of the Pealip Redhorse, Moxostoma pisolabrum, from Oklahoma. Dactylogyrus pisolabrae is morphologically similar to Dactylogyrus apos, Dactylogyrus atripinnei, Dactylogyrus duquesnei, and Dactylogyrus niger, all parasitizing other species of suckers, by possessing a robust, sickle-shaped male copulatory organ, but differs from these and all other species of North American Dactylogyrus by possessing 2 unique wing-like projections opposite each other on the proximal portion of the accessory piece. Dactylogyrus pisolabrae represents the first monogenean reported from the Pealip Redhorse.

Monogenoidea (Dactylogyridae, Gyrodactylidae) from Red River Pupfish, Cyprinodon rubrofluviatilis (Cyprinodontiformes: Cyprinodontidae), from Kansas and Texas, USA.

BACKGROUND: The gills of Red River Pupfish (Cyprinodon rubrofluviatilis) collected from Kansas and Texas, U.S.A., were found to be infected with three monogenoideans, Fundulotrema prolongis, Gyrodactylus rubrofluviatilae n. sp., and a species of Salsuginus. RESULTS: Gyrodactylus rubrofluviatilae n. sp. appears to be a member of a group of six closely related species possessing hamuli with mesially folded roots and a linguiform ventral bar shield, and parasitizing closely related species of Cyprinodon of the North American Gulf Coast and inland waters of the Southwestern United States and northern México. Gyrodactylus rubrofluviatilae n. sp. differs from its close congeners in the morphology of the hamuli, ventral bar, ventral bar shield, and marginal hooks. Because the morphology of the male copulatory complex was not determined of what we believe will eventually be a new species of Salsuginus, a species description is deferred. This is the first report of any parasite from this host. CONCLUSIONS: Many North American species currently recognized within the Cyprinodontiformes have not yet been surveyed for species of Fundulotrema, Gyrodactylus, or Salsuginus. This, coupled with the high host specificity generally recognized for these monogeneans, portends there are likely additional new species yet to be discovered. When possible, to help augment morphological data, further studies should employ comprehensive intra- and interspecies molecular analyses to help resolve host-parasite phylogenies.

A new coccidian parasite (Apicomplexa: Eimeriidae: Eimeria) from the southern black racer, Coluber constrictor priapus (Reptilia: Ophidia: Colubridae) from Arkansas, USA.

Between April 2012 and October 2017, 18 southern black racers, Coluber constrictor priapus, were collected from nine counties of Arkansas (n = 13) and McCurtain County, Oklahoma (n = 5) and their faeces examined for coccidian parasites. One of 18 (6%) C. c. priapus harboured an eimerian that we describe here as new. Oocysts of Eimeria dunni sp. nov. were subspheroidal with a lightly pitted bi-layered wall measuring L × W 24.0 × 21.1 and L/W ratio of 1.2. A micropyle was absent but an oocyst residuum and polar granule were present. Sporocysts were ovoidal and measured 11.9 × 8.1 with L/W of 1.5. A Stieda body was present but substieda and parastieda bodies were absent. The sporocyst residuum was composed of medium-sized granules aligned along perimeter of sporocyst or in a dispersed mass. This represents the first valid eimerian reported from the southern black racer.

Two New Species of Plagioporus (Digenea: Opecoelidae) from the Ouachita Madtom, Noturus lachneri, and the Banded Sculpin, Cottus carolinae, from Arkansas.

Plagioporus ictaluri n. sp. and Plagioporus carolini n. sp. are described from the intestines of the Ouachita Madtom, Noturus lachneri, and the Banded Sculpin, Cottus carolinae, respectively, from adjacent drainages in Arkansas. The new species are morphologically most similar to one another and in turn similar to Plagioporus sinitsini, Plagioporus chiliticorum, Plagioporus serratus, and Plagioporus hypentelii, but they can be distinguished from these congeners in possession of an excretory vesicle that extends anteriorly to the level of the anterior testis as opposed to 1 reaching only the posterior testis ( P. hypentelii) or 1 confined to the posttesticular space ( P. sinitsini, P. serratus, and P. chiliticorum), a feature that necessitates altering the generic diagnosis for the genus. Plagioporus ictaluri n. sp. is distinguished from Plagioporus carolini n. sp. in having tandem vs. oblique testes, a submedian to median ovary as opposed to 1 that is dextral, a ventral sucker occupying 53-71% of the body width (BW) vs. 80-92% of the BW, an oral sucker occupying 36-47% of the BW as opposed to 49-58% of the BW, and a pharynx occupying 21-26% of the BW compared to 28-36% of the BW. A Bayesian inference analysis of partial 28S rDNA sequences of the 2 new species and those of 34 opecoelids obtained from GenBank found that P. ictaluri and P. carolini formed a highly supported clade that was sister to P. chiliticorum and in turn to P. sinitsini. These 4 species are notably the only Nearctic plagioporids included in the analysis without a uterus extending to the posterior end that lack a confluent vitelline field in the posttesticular space. This study includes the first species of Plagioporus to be described from an ictalurid host and the first species in the genus to be described from a cottid east of the Rocky Mountains.

Three new species of Plagioporus Stafford, 1904 from darters (Perciformes: Percidae), with a redescription of Plagioporus boleosomi (Pearse, 1924) Peters, 1957.

A form of Plagioporus Stafford, 1904 is described from the intestine of three North American species of darters (Perciformes: Percidae) from River West Twin, Wisconsin, USA, that we consider to be conspecific with Plagioporus boleosomi (Pearse, 1924) Peters, 1957 based on similarities in the sucker ratio, extent of the forebody, shape and position of the testes, vitellarium distribution and terminal genitalia. Three new species of Plagioporus are described from the intestine of darters as follows: Plagioporus fonti n. sp. from Percina nigrofasciata Agassiz in Florida, USA, Plagioporus limus n. sp. from Etheostoma squamosum Distler in Arkansas, USA and Plagioporus aliffi n. sp. from Etheostoma blennioides newmanni Miller in Arkansas, USA. Morphologically Plagioporus fonti n. sp., Plagioporus limus n. sp. and Plagioporus aliffi n. sp. are most similar to one another and to P. boleosomi, Plagioporus lepomis Dobrovolny, 1939 and 'P. etheostomae', a nomen nudum for a species described from Etheostoma blennioides Rafinesque in Kentucky, USA, all of which are collectively distinguished from congeners in having a combination of confluent vitellarium in the post-testicular space and absence of vitelline follicles with their entire length distributed in the forebody. Plagioporus fonti n. sp., P. limus n. sp. and P. aliffi n. sp. are respectively distinguished from one another and their closest congeners in having the anterior extent of the vitellarium in the anterior half of forebody to slightly anterior to the ventral sucker as opposed to one approximately at the level of the posterior margin of the ventral sucker, possession of an excretory vesicle reaching the anterior testis as opposed to one only reaching the posterior testis and having a longer than wide oral sucker and a wider than long ventral sucker. A Bayesian inference (BI) analysis of partial 28S rDNA sequences was conducted using the three new species and 24 sequences of opecoelids retrieved from GenBank, including ten species of Plagioporus. Plagioporus aliffi n. sp., Plagioporus fonti n. sp. and P. boleosomi comprised a moderately supported sister group to a clade containing all species of Plagioporus except Plagioporus limus n. sp. and Plagioporus shawi (Mcintosh, 1939) Margolis, 1970. Plagioporus limus and in turn P. shawi were resolved as sister to all other congeners with high and moderate support, respectively.

A new burrowing crayfish of the genus Fallicambarus Hobbs, 1969 (Decapoda: Cambaridae) from the Red River Drainage of the southcentral United States.

A new primary burrowing crayfish, Fallicambarus schusteri, is described from the Red River drainage of extreme southeastern Oklahoma and southwestern Arkansas and is placed in the subgenus Fallicambarus. The species occurs in roadside ditches that seasonally flood and have silt and silt-loam dominated soils. Falllicambarus schusteri differs from all other members of the genus Fallicambarus in possessing a thin gradually tapering central projection and a wide triangular cephalic process on the first pleopod of form I males, a sufflamen on the cheliped, and an antennal scale that is widest at its midpoint.

Evolutionary consequence of a change in life cycle complexity: A link between precocious development and evolution toward female-biased sex allocation in a hermaphroditic parasite.

The evolutionary consequences of changes in the complex life cycles of parasites are not limited to the traits that directly affect transmission. For instance, mating systems that are altered due to precocious sexual maturation in what is typically regarded as an intermediate host may impact opportunities for outcrossing. In turn, reproductive traits may evolve to optimize sex allocation. Here, we test the hypothesis that sex allocation evolved toward a more female-biased function in populations of the hermaphroditic digenean trematode Alloglossidium progeneticum that can precociously reproduce in their second hosts. In these precocious populations, parasites are forced to self-fertilize as they remain encysted in their second hosts. In contrast, parasites in obligate three-host populations have more opportunities to outcross in their third host. We found strong support that in populations with precocious development, allocation to male resources was greatly reduced. We also identified a potential phenotypically plastic response in a body size sex allocation relationship that may be driven by the competition for mates. These results emphasize how changes in life cycle patterns that alter mating systems can impact the evolution of reproductive traits in parasites.

Two new species of coccidia (Apicomplexa: Eimeriidae) from ground skinks, Scincella lateralis (Sauria: Scincidae), from Arkansas, USA.

Between February 2011 and January 2014, 75 ground skinks, Scincella lateralis (Say) were collected from 13 counties of Arkansas and McCurtain County, Oklahoma, USA, and examined for coccidia. Two (3%) and 11 (15%) S. lateralis were found to be passing oöcysts of a new choleoeimerian and isosporan, respectively. Oöcysts of Choleoeimeria ouachitensis n. sp. are ellipsoidal to cylindroidal with a smooth, colourless, bi-layered wall and measure 27.2 × 15.6 µm, and have a length/width (L/W) ratio of 1.7; both micropyle and oöcyst residuum are absent, but 1-2 polar granule(s) are present. Sporocysts are ovoidal, 8.9 × 6.8 µm, L/W 1.3; neither Stieda, sub-Stieda and para-Stieda bodies are present; the walls have two valves joined by longitudinal sutures; a sporocyst residuum consisted of dispersed granules between sporozoites. Oöcysts of Isospora koberi n. sp. are ovoidal with a smooth, colourless, bi-layered wall and measure 25.1 × 20.5 µm, L/W 1.2; both micropyle and oöcyst residuum are absent, but a polar granule is rarely present. Sporocysts are ovoidal, 11.4 × 8.6 µm, L/W 1.3; a nipple-like Stieda body and a sub-Stieda body are present without a para-Stieda body; a sporocyst residuum consisted of condensed granules dispersed between sporozoites. This is the second choleoeimerian and third isosporan reported from S. lateralis.

A New Species of Eimeria (Apicomplexa: Eimeriidae) from Green Frog, Lithobates clamitans (Anura: Ranidae) from Arkansas, U.S.A.

Between April and October 2012, 20 juvenile and adult green frogs (Lithobates clamitans) were collected by hand or dipnet from 3 counties of Arkansas and examined for coccidial parasites. A single frog (5%) was found to be passing oocysts of a new eimerian species. Oocysts of Eimeria menaensis n. sp. were ellipsoidal to subspheroidal with a bilayered wall and measured (L × W) 25.4 × 15.6 (23-27 × 13-17) µm, with a L/W ratio of 1.6. A micropyle was absent but an oocyst residuum and polar granule were present. Sporocysts were spheroidal to subspheroidal and measured 5.0 × 5.0 (4-6) µm with L/W of 1.1. An indistinct Stieda body was present, but sub-and para-Stieda bodies were absent. The sporocyst residuum consisted of condensed granules dispersed between sporozoites. Sporozoites were elongate and attenuated at both ends with spheroidal anterior and posterior refractile bodies. This represents the second report of coccidia from L. clamitans and the first time a coccidian has been reported from a green frog from Arkansas.

A new species of Eimeria (Apicomplexa: Eimeriidae) from the eastern pipistrelle, Perimyotis subflavus (Chiroptera: Vespertilionidae), in Arkansas.

During November 2009 and March 2010, 20 adult eastern pipistrelles, Perimyotis (=  Pipistrellus) subflavus, were collected from Polk County, Arkansas, and their feces were examined for coccidian parasites. Two (10%) of the bats were found to be passing oocysts of an undescribed species of Eimeria. Oocysts of Eimeria heidti n. sp. were ovoidal to ellipsoidal, 26.1 × 20.5 µm (23-31 × 18-23 µm), with a bilayered wall, externally rough, internally smooth, and with a shape index of 1.3. Micropyle and oocyst residuum were absent, but a subspherical polar granule was often present. Sporocysts were ovoidal, 13.0 × 8.8 µm (11-15 × 7-13 µm), the shape index was 1.6, a Stieda body was present and sub-Stieda and para-Stieda bodies were absent. A sporocyst residuum consisting of multiple globules dispersed along the perimeter of the sporocyst and between the sporozoites were present, sporozoites were elongate, with a subspherical anterior refractile body and elongate posterior refractile body; a nucleus not discernible. This is the second coccidian reported from this host and the fourth instance of a coccidian species reported from an Arkansas bat.

LIFE-HISTORY VARIATION AND COMPARATIVE PHYLOGEOGRAPHY OF DARTERS (PISCES: PERCIDAE) FROM THE NORTH AMERICAN CENTRAL HIGHLANDS.

Phylogeography seeks to evaluate the relationship between genetic variation and geographic distribution of a species to examine the influence of historical events on divergence. Congruent phylogeographic patterns in codistributed species indicate historical association of the taxa being compared, and the uniform action of biogeographic events in shaping genetic variation. We sought to evaluate the congruence of patterns of genetic variation of five closely related fish species across a well-defined biogeographic boundary. We gathered allozymic and mitochondrial DNA (mtDNA) sequence data for five species of darters (Percidae: Etheostomatini) from populations distributed among biogeographic regions in the Ozark and Ouachita highlands of the south-central United States. Comparisons among species revealed noncongruence in the magnitude of genetic divergence in both allozymes and mtDNA sequences. We hypothesized that noncongruence resulted, in part, from differences in life histories of the species in our comparison. To address this hypothesis, we evaluated the association between gene flow (measured by Ne m) and variation in body size and fecundity variables because they have been shown to influence gene flow in fishes. Correlation analysis revealed an association between gene flow and fecundity (r = 0.88), but not with body size (r = 0.36) or reproductive investment per individual (r = -0.23). The result was similar when independent contrasts of the original variables were used in correlation analyses. Phylogeographic analysis of mtDNA sequence data indicated the importance of history, evident in gene trees of Percina nasuta and Percina phoxocephala. Divergence rates between these two taxa may differ because of historically persistent differences in population sizes, reflected in present-day abundance and fecundity differences. Conversely, Percina caprodes showed little evidence of divergence in mtDNA sequences and yielded the highest mean Ne m values from allozyme data. Comparisons among closely related, codistributed taxa may help discriminate among the possibilities for noncongruence in biogeographic studies by allowing evaluation of the influence of life history on patterns of gene flow.