Search

Nematodes collected from the intestine of sompat grunt Pomadasys jubelini Cuvier, 1830 from Hann Bay in Dakar, Senegal represent a new species described herein as Dichelyne (Neocucullanellus) dakarensis n. sp., and investigated with the use of light and scanning electron microscopy. The new species differs from its congeners based on several characteristics, especially because the subgenus Neocucullanellus is the only 1 that has 2 ceca. In addition, the new species diagnosis is based on the number and arrangement of the caudal papillae as well as the size of the veil of spicules. Morphological data were supported by molecular analysis. Results obtained using SSU rDNA and COI distinguished the present specimens from other cucullanids. Molecular data indicated the close relatedness between the new species and Dichelyne cotylophora Ward and Magath, 1917., (© American Society of Parasitologists 2024.)

Haliotrema Pteroisi: Paperna, 1972 (Monogenoidea: Dactylogyridae) was found parasitizing the gill lamellae of devil firefish, Pterois miles (Bennet) (Perciformes: Scorpaenidae), in the Red Sea off Safaga (26°44'N, 33°56'E), Egypt. The parasite species was described based on morphological features of available specimens and transferred to PlatycephalotremaKritsky and Nitta, 2019 (Dactylogyridae) as Platycephalotrema pteroisi (Paperna, 1972) n. comb. The occurrence of Pl. pteroisi off Safaga, Egypt, represented a range extension for the helminth of about 160 km to the southwest of the southern end of the Gulf of Aqaba. The transfer of the species to Platycephalotrema based on an evaluation of morphological features was supported by an analysis of molecular sequences of the 28S rDNA gene of Pl. pteroisi and 49 other dactylogyrid species. Maximum-likelihood, Bayesian inference, and maximum parsimony analyses of this dactylogyrid sequence data revealed H. pteroisi to nest with significant support within the clade of Platycephalotrema spp. During the literature review of dactylogyrid species infecting scorpionfishes, it was determined that Ancyrocephalus sp. of Dyer et al. from luna lion fish Pterois lunulata Temminck and Schlegel collected off Okinawa-jima, Japan represented an undescribed species of Platycephalotrema., (© American Society of Parasitologists 2024.)

During March 2023, 7 green sunfish (Lepomis cyanellus) and 2 bluegill (Lepomis macrochirus) were collected from the Black River (White River drainage) in Lawrence County, Arkansas. In addition, during March 2023 and again in May-June 2023, 13 L. cyanellus and 6 L. macrochirus were taken from Butcherknife and Big Fork creeks (Ouachita River drainage), Polk County, Arkansas, 9 L. cyanellus were collected from the Caddo River, Montgomery County, Arkansas, and 5 green sunfish were taken from Clear Creek at Savoy, Washington County, Arkansas. All fish had their gill, gallbladder, fins, integument, musculature, and other major organs examined for myxozoans. The gill of 1 of 34 (3%) L. cyanellus was infected with a new myxozoan, Myxobolus fergusoni n. sp. Qualitative and quantitative morphological data were obtained from fresh myxospores, and molecular data consisted of a 1,933-base-pair sequence of the partial small subunit (SSU) ribosomal RNA (rRNA) gene. Phylogenetic analysis grouped M. fergusoni n. sp. with other centrarchid-infecting myxobolids from North America and placed this cluster in a larger clade comprising myxozoans that infect North American and European esocids, a North American aphredoderid, European percids, and a gasterosteid from Japan. Myxobolus fergusoni n. sp. infects the gill arches of L. cyanellus, similar to Myxobolus cartilaginis (Hoffman, Putz, and Dunbar, 1965), which was described from head cartilage, gill arches, and large fin rays of L. cyanellus. Another is Myxobolus mesentericusKudo, 1920, which was described from the viscera of green sunfish. A large polysporic plasmodium filled with myxospores was present in a basifilamental location associated with multiple gill filaments at their junction with the gill arch. The intact plasmodium replaced connective tissue within the arch but elicited only mild proliferation of overlying epithelium and a minimal host inflammatory response. This is the third time a myxozoan has been described from L. cyanellus, as well as being the first time it has been described from an Arkansas specimen., (© American Society of Parasitologists 2024.)

Myxospores discovered floating free in the bile of marine fishes from the south-central coast of Vietnam were identified using morphological and molecular methods, leading to the description of 2 new species. Ceratomyxa chauvanminhi n. sp. was detected in 16% (8/50) of cultured barramundi Lates calcarifer (Bloch) specimens, and Ceratomyxa sekoi n. sp. was found in 20% (5/25) of wild largehead hairtail Trichiurus lepturus Linnaeus specimens. The spores of C. chauvanminhi n. sp. are very shallowly ovoid, slightly crescent shaped, and 11.5 ± 0.5 (10.7-12.4) μm thick, 5.8 ± 0.2 (5.4-6.1) μm long, and 5.5 ± 0.2 (5.2-5.7) μm wide. Their posterior angles are slightly concave at 158.7° ± 4.2° (151.3°-164.8°), and they possess 2 equal spherical polar capsules 2.5 ± 0.2 (2.1-2.9) μm in diameter. The spores of C. sekoi n. sp. are 5.6 ± 0.2 (5.0-6.1) μm long, 75.5 ± 4.8 (68.9-90.0) μm thick, and 5.5 ± 0.1 (5.4-5.6) μm wide, with 2 equal, slightly anterior spherical polar capsules 2.1 ± 0.2 (1.7-2.4) μm in diameter. Although C. sekoi n. sp. spores resemble those of species of MyxodavisiaZhao, Zhou, Kent, and Whipps, 2008, characterized by long tapering valves, genetic analyses distinctly place this new species within the Ceratomyxa Thélohan, 1892 lineage. This study contributes to the understanding myxosporean diversity in Vietnamese waters and highlights the difficulty associated with distinguishing between the genera Ceratomyxa and Myxodavisia., (© American Society of Parasitologists 2024.)

A total of 366 individuals of Lutjanus argentiventris (Peters, 1869) were collected over a 5-yr period (October 2018 to June 2022) from Acapulco Bay, Mexico. Parasite communities in Lutjanus argentiventris were quantified and analyzed to determine the main factors that generate changes in species richness and/or species composition over time. The digeneans and copepods were the best-represented parasite groups. The parasite communities were characterized by a high numerical dominance of ectoparasites, mainly isopod larvae. Species richness at the component community level (9-23 species) was similar to the reported richness in other Lutjanus spp. The parasite communities of Lutjanus argentiventris exhibited high variability in species composition, suggesting that each parasite species may respond differently to environmental changes. However, the species richness and diversity were fairly stable over time; therefore, a clear pattern of interannual variation was not observed. Variations in the community structure probably were due to factors such as host traits (e.g., feeding behavior and body size), and possible interannual differences in environmental factors amplified by the occurrence of the anomalous event of La Niña., (© American Society of Parasitologists 2024.)

Prevalence values for 3 digenean species of the family Opecoelidae were calculated during a half-year period from 20 individuals per month of the fish species Clinocottus analis, collected from an intertidal environment of Baja California, Mexico. Trematode species recovered were Opecoelus adsphaericus, Opecoelus cameroni, and Opecoelus pacificus. Of these, only O. adsphaericus was present throughout the study, whereas O. pacificus and O. cameroni were recorded for 1 or 2 mo, respectively, exhibiting relatively low prevalence values. The decrease in prevalence of O. adsphaericus coincides with the appearance of O. pacificus and O. cameroni; these last 2 species were found only in the largest hosts, and their presence represents new records for Mexican marine fauna., (© American Society of Parasitologists 2024.)

Based on previous molecular phylogenetic analyses, Bothriocestus n. gen. is erected to accommodate bothriocephalid tapeworms that have an elongate scolex, a well-developed apical disc, and a narrow neck region, parasitize freshwater fishes in the Holarctic, and were previously placed in the polyphyletic genus Bothriocephalus Rudolphi, 1808 (Cestoda: Bothriocephalidea). Bothriocestus claviceps (Goeze, 1782) n. comb., a parasite of eels (Anguilla spp.) in the Holarctic region, is designated as the type species. Another species of the new genus, Bothriocestus cuspidatus (Cooper, 1917) (syn. Bothriocephalus cuspidatusCooper, 1917) is redescribed from type and voucher specimens, and new material from the type host, the walleye, Sander vitreus (Mitchill, 1818) (Perciformes: Percidae), in Manitoba and Ontario (where the type locality is located) (Canada) and in New York state and Wisconsin. Bothriocestus cuspidatus of S. vitreus is characterized primarily by the possession of a narrow, long strobila (total length up to 18 cm) composed of distinctly craspedote, trapezoidal proglottids, with primary, secondary, and tertiary proglottids differing in size, and by an arrow-shaped (=cuspidatus) scolex that is distinctly broader than the first proglottids, widest near the base in lateral view and gradually becoming broader toward the anterior end in dorsoventral view. A "dwarf" form of B. cuspidatus (total length of 9-27 mm) from Johnny darter, Etheostoma nigrum Rafinesque, 1820, and tessellated darter, Etheostoma olmstedi Storer, 1842 (both Percidae: Etheostominae), is also characterized morphologically in the present paper., (© American Society of Parasitologists 2023.)

An undescribed species of KannaphallusUnnithan, 1957 (Monogenoidea: Heteraxinidae) was collected from the gills of the golden trevally Gnathanodon speciosus (Forsskål) (Carangidae) from Moreton Bay, Queensland, during January 2016 and from Ningaloo Reef, Western Australia, during December 2021 and June 2022. The diagnosis for Kannaphallus was emended and the new species, Kannaphallus raphidium, was described. Kannaphallus virilis of Young, nec Unnithan was placed in synonymy with K. raphidium. The distal components of the male reproductive system and the arrangement of the clamp rows of the haptor occurred as mirror images among specimens of K. raphidium, suggesting that the respective antipodes of K. raphidium may have reproductive implications and function in the site selection of the parasite on the host's gills. A specimen of K. raphidium from Western Australia was sequenced for the cytochrome c oxidase subunit 1 (COI) mtDNA and ITS2 rDNA barcoding markers, and the phylogenetically informative 28S rDNA marker. Maximum likelihood and Bayesian inference analyses based on a partial 28S rDNA alignment, including all comparable heteraxinid sequence data available, resolved the Heteraxininae and Cemocotylinae as reciprocatively paraphyletic and provided evidence that Kannaphallus may be paraphyletic. No taxonomic changes concerning the subfamilies and genera of the Heteraxinidae were proposed. Finally, Kannaphallus univaginalisRamalingam, 1960 and Cemocotylelloides univaginalis (Ramalingam, 1960) Nitta, Kondo, Ohtsuka, Kamarudin, and Ismail, 2022 are considered nomen nuda sensu the International Code of Zoological Nomenclature., (© American Society of Parasitologists 2023.)

Gill parasites can negatively affect hosts by altering behavior or causing adverse effects to host physiology. Most unionid mussel larvae (glochidia) are obligate parasites requiring fish hosts, but much of the literature concerning how these parasites affect their hosts has been limited to only a few study species of salmonids and mussels. Here, we test the effects of natural glochidia infection levels on resting metabolic rate and hypoxia tolerance of bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides using glochidia of the southern fatmucket mussel Lampsilis straminea, a warm-water unionid. We quantified oxygen uptake, hypoxia tolerance, and ability to regulate metabolic rate via respiration rate, critical dissolved oxygen values (DOcrit), and a regulation index (RI), respectively, to compare the effects of glochidia infection between infected and uninfected fish over 11 wk after host inoculation. Hosts were infected with glochidia at levels similar to those seen in wild, naturally occurring infections. At these levels, we observed no effects of glochidia infection on metabolic rate, DOcrit, or RI of infected versus control fish of either species over our 11-wk experiment. Glochidia infection on fish gills at levels expected under field conditions may not always induce an organismal-level (i.e., individual organism) response or cause host respiratory stress. Preventing respiratory stress from infection would be beneficial for both host and parasite, given that glochidia survival and dispersal depend on host survival., (© American Society of Parasitologists 2022.)

The round goby (Neogobius melanostomus) is an invasive species that has become one of the most abundant fish in the St. Lawrence River, Quebec, Canada over the past 15 yr. Since its introduction, the round goby has acquired a number of native parasites, yet little is known about the dynamics of parasite recruitment. To examine this question, young-of-the-year and juvenile round gobies were collected monthly from 2 localities in the river (Îles de la Paix, Île Dorval) from June through November 2012. At Îles de la Paix, round gobies (n = 180) were infected with 3 species of parasites, all larval stages (Diplostomum spp., Tylodelphys scheuringi, Neoechinorhynchus tenellus). Prevalence of the digenean Diplostomum spp. varied from 3.3 to 13.3%, and mean abundance from 0.03 to 0.53 from June through September, with a maximum in August. The digenean T. scheuringi was seen only in August, at a prevalence of 10.0% and a mean abundance of 0.53. The acanthocephalan N. tenellus was observed in June, August, and September, prevalence ranging from 3.3 to 10.0% and mean abundance from 0.03 to 0.27. Maximum infection for all 3 species occurred in August. All infected fish were ≥44 mm in total length (TL). Fish infected with more than 1 parasite species were >60 mm TL. No round goby (n = 178) was infected at Île Dorval. This study demonstrated that the invasive round goby starts to acquire parasite infections in the St. Lawrence River in the first year of life and may contribute to the transmission of some parasites within this ecosystem., (© American Society of Parasitologists 2022.)

Sunfish (Lepomis spp.) are among the most common piscine inhabitants of freshwater lakes and ponds in North America. Lepomis spp. breed at the same time creating hybrid zones, where genetically distinct populations mate and produce mixed offspring that are sexually viable hybrids. One aspect of hybridization that may have important consequences is parasitism and its patterns of recruitment in the hybrid sunfish. This study investigated these patterns both at the level of the individual parasite species as well as in the parasite communities infecting the fish. Two sample sites possessing hybrid sunfish populations were investigated: 1 system had bluegill sunfish (Lepomis macrochirus), redear sunfish (Lepomis microlophus), and their hybrids, while the other system had bluegill sunfish (L. macrochirus), green sunfish (Lepomis cyanellus), and their hybrids. The hybrids were infected by mostly generalist parasites that commonly infect all Lepomis spp. Most of the individual parasite species followed a dominance pattern (59.1%) of infection, where parasite abundance in hybrids resembled at least one of the parental species, with the remainder exhibiting intermediate levels of parasitism, supporting an additive pattern of parasite recruitment (40.1%). At the community level, the patterns of parasite recruitment differed in L. macrochirus × L. microlophus hybrids, which showed a dominance pattern, and L. macrochirus × L. cyanellus hybrids, which showed an additive pattern of parasite recruitment. These differences in parasite recruitment between hybrid groups may be attributed to varying degrees of dietary and niche overlap between the parental species in the 2 study systems., (© American Society of Parasitologists 2022.)

In comparative studies, the advantage of increased sample sizes might be outweighed by detrimental effects on sample homogeneity and comparability when small numbers of hosts from a different demographic of the same species are included in samples. A mixed sample of sunfishes (Lepomis spp.) was subdivided in different ways and examined using cumulative performance curves to determine whether the exclusion of larger hosts from a single-species sample and/or the inclusion of hosts of the same size demographic from closely related host species would produce more homogeneous samples. The exclusion of larger hosts from the single-species samples tended to reduce the aggregation of the infrapopulation samples, and mixed-species samples of smaller fishes tended to have lower degrees of aggregation for a given sample size relative to the single-species sample. Cumulative performance curves for diversity and richness, in concert with nonmetric multidimensional scaling of the infracommunities, demonstrated sunfish size to be a more reliable determinant of infracommunity similarity than sunfish species in this particular sample. The results demonstrate that cumulative aggregation curves can be an effective tool for delineating homogeneous and comparable subsamples and that, under some circumstances, it is possible to offset the smaller sample sizes that result from the exclusion of older/larger hosts by the addition of congeneric or confamilial hosts within the same size/age classes as the stratified sample., (© American Society of Parasitologists 2021.)

Stable isotope analyses of carbon and nitrogen (δ13C and δ15N) are useful for elucidating consumer relationships of free-living organisms, as carbon isotopes indicate dietary carbon sources and incremental increases in nitrogen isotopic enrichment are correlated with increases in trophic position. However, host-parasite relationships are more difficult to interpret using isotopes, as data from different host-parasite systems rarely show any consistent pattern. This inconsistency of pattern reflects the complexity of host-parasite relationships, but also the scarcity of data from a diverse assemblage of host-parasite systems. We present stable isotope data from a host-parasite system including 2 ecologically contrasting helminths, an acanthocephalan (Filisoma filiformis) and a digenetic trematode (Enenterum sp.), which co-occur in the intestine of the same marine fish (Kyphosus bigibbus), the diet of which consists almost exclusively of macroalgae. We obtained δ13C and δ15N data from K. bigibbus muscle, stomach contents, and pooled infrapopulations of Enenterum sp. and F. filiformis. Consistent with other isotope studies including acanthocephalans, F. filiformis was depleted in δ13C and δ15N relative to K. bigibbus. Although Enenterum sp. exhibited values for δ13C similar to those for F. filiformis, they were enriched in δ15N relative to the acanthocephalan, with a signature similar to that of K. bigibbus. These findings are discussed within a host-ecosystem context, highlighting the importance of considering species-specific biology when interpreting host-parasite relationships using stable isotopes. Our study adds to the growing body of literature indicating that absorptive feeders, such as acanthocephalans, are typically depleted in δ13C and δ15N relative to their hosts, whereas trematodes, with a greater diversity of feeding opportunities, exhibit a wide variety of isotopic signatures across life stage and different host-parasite systems., (© American Society of Parasitologists 2021.)

A helminthological analysis was performed on 91 specimens of the porkfish, Anisotremus virginicus (Linnaeus) (Haemulidae), captured in coral reef habitats of the Parque Nacional Sistema Arrecifal Veracruzano (PNSAV) (Veracruz Reef System National Park), in Veracruz, Mexico. A total of 22 helminth taxa were recorded: 9 digeneans, 6 monogeneans, 1 cestode, 4 nematodes, and 2 acanthocephalans. From the 22 taxa, 11 are new host records and 7 are new geographic records. The highest prevalence was found for Monorchis latus Manter, 1942 (69%), and Mexicana anisotremumCezar, Paschoal and Luque, 2012 (68%), and the highest mean intensity was found for M. anisotremum (19.6), M. latus (18.9), and Dollfusentis chandleri Golvan, 1969 (10.8). Other important values were the component community richness (S = 22), diversity (Shannon index H' = 1.6), and infracommunity level (S = 3.1 ± 1.4; Brillouin index, H = 0.52 ± 0.3), which were similar to those found in other marine fish at the same study site. Our result represents a significant range extension for several helminth taxa. The parasite communities of A. virginicus rank among the richer parasite communities of neotropical marine fishes. In addition, the results reveal the PNSAV is a diverse area for the parasite assemblage of neotropical reef marine fishes, particularly of haemulids but also for other fish families., (© American Society of Parasitologists 2021.)

Morphological and molecular evaluation of tapeworms of the genus Bothriocephalus Rudolphi, 1808 (Cestoda: Bothriocephalidea), based on newly collected and uniformly fixed worms from freshwater fishes in Canada and the United States has revealed unexpected diversity. With a combination of selected morphological features and 4 molecular markers (18S rDNA V8 region, ITS1, ITS2, and COI gene sequences), the following morphotypes and lineages of the Bothriocephalus cuspidatus Cooper, 1917 complex were identified, several of which are specific to their respective fish definitive hosts and may represent separate species: B. cuspidatus sensu stricto from walleye, Sander vitreus (type host), which likely includes a miniature morphotype from Johnny darter, Etheostoma nigrum (both Percidae); Bothriocephalus morphotype from pumpkinseed, Lepomis gibbosus (Centrarchidae); and Bothriocephalus morphotype from rock bass, Ambloplites rupestris (Centrarchidae). The Bothriocephalus morphotype from goldeye, Hiodon alosoides (Hiodontidae), may also represent a separate lineage (possibly Bothriocephalus texomensisSelf, 1954) but requires additional studies. A morphotype from smallmouth bass, Micropterus dolomieu, based on a single specimen, is morphologically and genetically very similar to the morphotype from rock bass. Morphological study of the scolex and strobila of heat-killed and fixed specimens has revealed consistent differences, often subtle, that allowed us to differentiate between these morphotypes., (© American Society of Parasitologists 2020.)

In the present paper, species of the Proteocephalus -aggregate de Chambrier, Zehnder, Vaucher, and Mariaux, 2004 (Cestoda: Proteocephalidae) reported from centrarchid and percid fishes in North America are reviewed, and their taxonomic status is critically assessed based on a study of type specimens and new material from Canada and the United States. The following 3 species, supposedly strictly specific to their fish definitive hosts, are recognized as valid: (1) Proteocephalus fluviatilis Bangham, 1925 (new synonyms Proteocephalus osburni Bangham, 1925 and Proteocephalus microcephalus Haderlie, 1953 ; Proteocephalus ' robustus ' nomen nudum) from the smallmouth and largemouth bass, Micropterus dolomieu (Lacépède) (type host) and Micropterus salmoides (Lacépède) (both Centrarchidae); (2) Proteocephalus luciopercae Wardle, 1932 (new synonym Proteocephalus stizostethi Hunter and Bangham, 1933 ) from the walleye, Sander vitreus (Mitchill) (type host), and sauger, Sander canadensis (Griffith et Smith) (Percidae); and (3) Proteocephalus pearsei La Rue, 1919 , a parasite of the yellow perch, Perca flavescens Mitchill (Percidae). All species are illustrated based on new, properly heat-fixed material. Scanning electron micrographs of the scoleces of percid tapeworms P. luciopercae and P. pearsei , as well as the bass tapeworms P. fluviatilis and Proteocephalus ambloplitis ( Leidy, 1887 ), the latter of which does not belong to this Proteocephalus -aggregate, are provided for the first time together with a simple key to species identification of proteocephalids from centrarchiform and perciform teleost fishes.

Snappers from the southern Gulf of Mexico (SGM) and Mexican Caribbean (CAR) were examined for parasitic nematodes to determine their richness, composition, and infection parameters (prevalence and mean intensity). From February 2016 to March 2018, 431 individuals of 8 snapper species were collected in 6 localities. In all, these fishes were parasitized by 2,275 individual nematodes belonging to 13 taxa: Terranova sp. was found in 7 of 8 host species and showed the highest prevalence (23%), while the rest had lower values (<10%). Lutjanus griseus (Linnaeus) harbored the highest species richness (10 species), followed by Lutjanus apodus (Walbaum) (8 species). Most localities were similar in terms of species richness but differed in the specific composition. Eight nematode taxa represent new host records for the family Lutjanidae (Gill), thus increasing to 22 the nematode taxa in the SGM and CAR. There is a potential risk to public health due to the presence of nematodes with zoonotic potential (as Anisakis sp.) and the habit in the region of eating raw fish (cebiche).

A new species of nematode, Ascarophis morronei n. sp. (Cystidicolidae), is described from the stomach wall of the woolly sculpin Clinocottus analis (Cottidae) collected in the rocky intertidal from northwestern Baja California, Mexico. Collected nematodes were studied using both light and scanning electron microscopy. Sequence fragments for 18S rDNA molecular markers were obtained from the new nematode species, in order to test its position within the family Cystidicolidae under a phylogenetic context. Main characters distinguishing this new species include the reduced labia and the morphology of the eggs, distances of nerve ring and excretory pore from the anterior end, and left spicule of males. The new species described here is the second for the genus Ascarophis reported as adult in the Southern California Bight, and the first one recorded for the fish genus Clinocottus .

Dichelyne ( Cucullanellus) dichelyneformis ( Szidat, 1950 ) Petter, 1974 , was collected in the intestine of the rock cod, Eleginops maclovinus, in the Bay of Corral, Chile, and redescribed based on light and scanning electron microscopy. The correct arrangement of caudal papillae and post deirids, the shape of gubernaculum, and the morphology and number of denticles surrounding the oral opening are described for the first time. These characteristics along with the excretory pore position, size of spicules, and presence of a nodular thickening near the distal end of the spicules differentiate D. ( C.) dichelyneformis from the other congeners reported in South America and in the Antarctic. The new congeneric species found in E. maclovinus differs from D. ( C.) dichelyneformis based on the larger males, larger and more numerous denticles with a smooth surface, weakly developed sclerotized plates in esophastome, excretory pore and deirids posterior to nerve ring, shorter gubernaculum and spicules with no thickening on their distal region, lower spicules/body length ratio (10.4-15.1%), and a papilla-like phasmids closer to pairs 8 and 10.

Bluegill sunfish ( Lepomis macrochirus) are an important North American sport fish distributed across the United States and Canada. These fish are sexually dimorphic, with males being larger and more brightly colored than females. Additionally, there are 2 male morphotypes, dominant, brightly colored α-males, and β-males, which resemble females in both appearance and behavior. The 2 male morphotypes differ significantly in terms of mating behavior, territoriality, and diet. These behavioral and feeding differences may result in α-males harboring greater parasite diversity and parasite loads compared to β-males. This was tested by collecting, necropsying, and identifying parasites from 636 L. macrochirus sampled from 9 ponds in northwest Virginia and comparing parasite species richness and parasite load in the male morphotypes. The parasite infracommunities infecting the male morphotypes differed significantly between them at 7 of the 9 sample sites. When compared to β-males, α-males consistently had greater parasite species richness as well as greater abundance for a majority of both trophically and non-trophically transmitted parasite species sampled in this study. The separation of male morphotypes must be accounted for in studies of L. macrochirus parasites due to sex bias differences between males and females being masked when male morphotypes are combined.

Two new species of myxosporeans are described from the gallbladders of estuarine stonefish, Synanceia horrida, and reef stonefish, Synanceia verrucosa, from localities off Cairns, in tropical north Queensland and in Moreton Bay in southern Queensland, Australia. Sphaeromyxa horrida n. sp. can be distinguished from congeners in the morphologically distinct "balbianii" species group within Sphaeromyxa on the basis of morphometric differences in length and width of mature spores, length and width of polar capsules, and unique small-subunit (SSU) ribosomal (rDNA) sequence composition relative to other taxa. Replicate SSU rDNA sequences generated from Sph. horrida n. sp. collected from Sy. horrida and Sy. verrucosa in tropical north Queensland and from Sy. horrida in Moreton Bay were identical, suggesting that this species is widely distributed along the east coast of Australia. Myxidium lapipiscis n. sp. can be distinguished from the majority of described Myxidium species on the basis of its relatively small mature spore size (6.1-7.9 μm long × 3.1-3.9 μm wide), and its unique SSU rDNA sequence. Specimens putatively identified as M. lapipiscis n. sp. were found in Sy. horrida from both tropical north Queensland and Moreton Bay, suggesting that this taxon is also widely distributed along the east coast of Australia. However, no molecular data were available for the specimens from tropical north Queensland for comparative genetic analyses. Bayesian inference and maximum likelihood analysis of the SSU rDNA sequences for these 2 new species revealed that Sph. horrida n. sp. formed a strongly supported clade with Sphaeromyxa zaharoni Diamant, Whipps, and Kent, 2004, which was described from the scorpaeniform, Pterois miles, from the Red Sea. This is the first report of myxozoans infecting stonefish (Synanceiidae).

Raphidascarididae are among the most abundant and widespread parasitic nematodes in the marine environment. The life-cycle of most raphidascaridid species is poorly known and information about their distribution and host range is lacking in many geographical areas, as is the taxonomy of several species. A study of larval and adult stages of Hysterothylacium fabri (Rudolphi, 1819) Deardorff and Overstreet, 1980 (Nematoda: Raphidascarididae) infecting the striped goatfish Mullus surmuletus Linnaeus, 1758 (Mullidae) and the Mediterranean stargazer Uranoscopus scaber Linnaeus, 1759 (Uranoscopidae) from the Ionian Sea (central Mediterranean) has been carried out by combining light and scanning electron microscopy observations and molecular analyses through polymerase chain reaction-restriction fragment length polymorphism and sequencing of the ITS rDNA gene. Results indicate that U. scaber and M. surmuletus represent suitable definitive and intermediate/paratenic hosts of H. fabri, respectively, in the Mediterranean and highlight the importance of combining genetic and morphological data to study the taxonomy and epidemiology of parasites widely distributed in different fish species and aquatic ecosystems.

The trematode Posthodiplostomum minimum MacCallum, 1921 (white grub) is a common parasite of centrarchid fishes, frequently reaching high prevalence and intensity in local populations. However, significant variation in infection has been observed across Lepomis Rafinesque, 1819 sunfish species, which are common and abundant hosts for this parasite. Previous observations suggest both extrinsic factors (e.g., habitat-specific characteristics and environmental parameters) and intrinsic factors (e.g., host size, behavior, and susceptibility) as important predictors of infection in this parasite-host system. In the present study, we evaluated the prevalence and intensity of P. minimum in 6 sympatric species of Lepomis sunfish (total of 563 individuals) across 9 lakes in eastern Ohio, U.S.A., that range in surface area from 5.6 to 1,448.7 hectares, and assessed the importance of both extrinsic and intrinsic factors as predictors of infection. We found that collection site (extrinsic factor) and host body mass and species identity (intrinsic factors) were the strongest predictors of infection intensity. Specifically, infection intensity was negatively associated with lake surface area and positively associated host body mass. Lepomis macrochirus (bluegill sunfish) and hybrid sunfish displayed the highest infection intensities, whereas Lepomis cyanellus (green sunfish) and Lepomis gulosus (warmouth sunfish) were significantly less burdened. We were unable to conclude if the observed variation among host species was due to host ecology or susceptibility. These general findings were supported by classification and regression tree (CART) analysis, which optimally partitioned variation in individual host infection intensities by using lake size and host body mass (but not host species identity). Although infection intensity was negatively associated with lake surface area (even among host individuals of the same size and species), the causal mechanisms involved remain unresolved and should be the impetus of future work on this parasite-host system.

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.

The acanthocephalan Paratrajectura longcementglandatus n. gen., n. sp. (Transvenidae) is described from specimens of 2 perciform fish species, Nemipterus japonicus Bloch (Nemipteridae) and Otolithes ruber Bloch and Schneider, collected in the marine territorial waters of Iraq and Iran in the Arabian Gulf. Metal analysis of hook tip, middle, and base is also described using energy disruptive analysis for X-ray. The new genus is distinguished from the closely related genus Trajectura Pichelin and Cribb, 2001 described from wrasses (Labridae) (Perciformes) in the Pacific off Australia and Japan by having a proboscis with apical epidermal cone, long rhadinorhynchid-like tubular cement glands, relatively short and lobulated lemnisci, all proboscis hooks with prominent roots, females with subterminal gonopore and a rounded projection on the antero-dorsal end of the trunk, and males with elongate pre-equatorial testes reaching proboscis receptacle. In Trajectura, the proboscis lacks apical epidermal cone, the cement glands are pyriform or ovoid, the lemnisci are digitiform and considerably longer than the receptacle, the posterior proboscis hooks are rootless, the females have prominent finger-like trunk projection and terminal gonopore, and males with equatorial testes that may not be elongate and may be distant from the receptacle. The importance of cement glands in the diagnosis of genera and families in acanthocephalan taxonomy is stressed. Other features especially the type and arrangement of hooks on the proboscis, but not hook roots, are comparable in the 2 genera. Diagnosis of the family Transvenidae is emended.

New records of Macrovalvitrematidae Yamaguti, 1963 are reported from Puerto Rico including Buccamagna archosarga n. gen., n. sp. from the western Atlantic sea bream Archosargus rhomboidalis, Pseudotagia pomadasys n. sp. from the roughneck grunt Pomadasys corvinaeformis, and new locality records for the species Neopterinotrematoides avaginata Suriano, 1975 and Macrovalvitrema argentinensis (Suriano, 1975) n. comb. from the whitemouth croaker Micropogonias furnieri . Buccamagna n. gen. is based on the anterior end and the oral disc being much larger and wider than width of the body proper, by having a pair of rectangular and sclerotized oral suckers, by lacking a pharynx, by having an excessive narrowness in the proximal area of both valves, and by having both valves of the 3 pairs of large clamps armed with several accessory sclerites. Pseudotagia pomadasys n. sp. is distinguished by the absence of serration of lateral sclerites and the relative size of the clamps, having the 2 larger pairs positioned centrally in the haptor and the 2 smaller pairs in the outer positions. Macrovalvitrematoides and Neomacrovalvitrema are synonymized with Macrovalvitrema, which is amended to include Macrovalvitrema micropogoni (Pearse, 1949) n. comb. and Macrovalvitrema argentinensis (Suriano, 1975) n. comb. based on recognition of identical clamp morphologies. In this study the clamp is emphasized as the key taxonomic character for macrovalvitrematid genera. Except for Pseudotagia, the Macrovalvitrematidae have distinctively longer than wide clamps (at least twice as long as wide); with the dorsal valve larger and with a more-complex skeletal structure (g1, g2, i, k, and f sclerites) than ventral valve (c and d sclerites); and 2 clamp morphologies. Characteristics not previously described but present in all macrovalvitrematid monogeneans except Pseudotagia included: (1) asymmetrical plate (plate b) along the ventral valve with a thin fissure on one side, and (2) mirror image arrangement of the pairs of clamps.

Parasite assemblages acquired through trophic interactions in fish hosts are increasingly cited as a means to determine pollution effects on water quality and food web structure. We examined gastrointestinal parasite community changes above and below coal mine input from 597 individuals representing 3 species of sunfish: green sunfish ( Lepomis cyanellus ), bluegill ( L. macrochirus ), and longear sunfish ( L. megalotis ). Hosts were collected from 6 sites in or near the south fork of the Saline River Basin in southern Illinois in the spring and fall of 2006. Three sites received no known effluent from coal mines. An additional 3 sites received effluent termed acid mine drainage (AMD). We recovered 1,064 parasites from 12 genera. The parasite community in sunfish collected downstream nearest to the source of AMD was significantly different from 3 upstream sites. In addition, 2 sites farther downstream receiving AMD were different from 2 of 3 reference sites. However, there was also considerable variability in parasite assemblages between sites grouped as above or below coal mine effluent. Several parasite species responded to changes in water quality. Spinitectus sp. (Nematoda), which uses sensitive mayfly hosts to complete its life cycle, was less abundant at sites downstream of coal mine effluent in both green sunfish and bluegill. In contrast, 2 acanthocephalans ( Neoechinorhynchus sp. and Eocollis arcanus) and a nematode ( Spiroxys sp.) were found in green sunfish more frequently in areas downstream of AMD. This study further suggests metazoan parasites may be useful as indicators of water quality; however, variability among similar sites may limit their application. In addition, strong assemblage differences were found among the 3 sunfish species, suggesting variable habitat usage and potential resource partitioning among congeneric fish hosts in streams.

Parasite host specificity has important implications for species diversity estimates, food web dynamics, and host shifts. "White grub" is the metacercaria stage of a fluke ( Posthodiplostomum minimum ) that occurs in many fish species, but no attempt has been made to quantify variation in host use by this worm. Here we used 2 approaches to evaluate host specificity within the strain that infects centrarchids ( P. minimum centrarchi). First, we measured parasite loads in 2 centrarchid hosts, bluegill ( Lepomis macrochirus ) and white crappie ( Pomoxis annularis ), from Spring Lake in McDonough County, Illinois. We found that infection levels differed significantly between these hosts. Prevalence in bluegill was 100% and the median intensity was 940 metacercariae, but only 57% of white crappie were infected (median intensity = 4). Site specificity of white grub also differed significantly between the 2 hosts. In bluegills, kidneys were most heavily infected, whereas in white crappies, livers harbored the most worms. We also performed a literature survey of P. minimum prevalence estimates from 14 centrarchid species from other localities. We calculated the mean white grub prevalence for each host species and used this to calculate STD*, a quantitative index of host specificity. STD* was 1.33, significantly closer to the value for a specialist (STD* = 1.00) than a generalist (STD* = 2.00). This reflects the fact that P. minimum prevalence is higher in Lepomis species than it is in centrarchids outside this genus. These data show that P. minimum centrarchi specializes on Lepomis species, but the causes of this specialization are unknown. This worm may be a single species that differs in host use due to ecological or physiological host differences, or it may be a complex of species that vary in host use for similar reasons. Genetic data are required to evaluate these possibilities.

Recently, Pterois volitans, a Pacific species of lionfish, invaded the Atlantic Ocean, likely via the aquarium trade. We examined for internal and external parasites 188 individuals from 8 municipalities of Puerto Rico collected during 2009-2012, 91 individuals from Little Cayman, Cayman Islands, collected during the summers of 2010 and 2011, and 47 individuals from Lee Stocking Island, Bahamas, collected during the summer of 2009. In total, 27 parasite taxa were found, including 3 previously reported species from lionfish, the digenean Lecithochirium floridense, the leech Trachelobdella lubrica, and an Excorallana sp. isopod. We also report another 24 previously unreported parasite taxa from lionfish, including digeneans, monogeneans, cestodes, nematodes, isopods, a copepod, and an acanthocephalan. Among these parasites, several were previously unreported at their respective geographic origins: We report 5 new locality records from Puerto Rico, 9 from Cayman Islands, 5 from the Bahamas, 5 from the Caribbean, and 3 from the subtropical western Atlantic region. Three parasites are reported to associate with a fish host for the first time. The parasite faunas of P. volitans among our 3 study sites were quite different; most of the species infecting lionfish were generalists and/or species that infect carnivorous fishes. Although our study did not assess the impact of parasites on the fitness of invasive lionfish, it provides an important early step. Our results provide valuable comparative data for future studies at these and other sites throughout the lionfish's invaded range.

Ichthyophonus-infected Pacific herring, Clupea pallasii , were allowed to decompose in ambient seawater then serially sampled for 29 days to evaluate parasite viability and infectivity for Pacific staghorn sculpin, Leptocottus armatus . Ichthyophonus sp. was viable in decomposing herring tissues for at least 29 days post-mortem and could be transmitted via ingestion to sculpin for up to 5 days. The parasite underwent morphologic changes during the first 48 hr following death of the host that were similar to those previously reported, but as host tissue decomposition progressed, several previously un-described forms of the parasite were observed. The significance of long-term survival and continued morphologic transformation in the post-mortem host is unknown, but it could represent a saprozoic phase of the parasite life cycle that has survival value for Ichthyophonus sp.

A total of 21 helminth species were recovered from 52 specimens of red snapper, Lutjanus campechanus , captured in the reef Santiaguillo, Parque Nacional Sistema Arrecifal Veracruzano, State of Veracruz, in the Southern Gulf of Mexico. These helminths included 9 trematodes (7 adults and 2 metacercariae), 4 nematodes (3 adults and 1 larva), 4 acanthocephalans (1 adult and 3 juvenile), 2 cestodes (both larvae), and 2 monogeneans. Sixteen of the 21 species are new host records; 7 are common species with a prevalence >40% and mean intensity >4.1. The monogenean Euryhaliotrema tubocirrus was the most-prevalent parasite with a prevalence of 78.8%, followed by the intestinal plerocercoids of Tetraphyllidea with a prevalence of 59.6%. The richness (S = 21), and diversity (Shannon index H = 2.17) in the component community, as well as in the infracommunity level (S = 5.1 ± 2.2, H = 0.92 ± 0.4), was similar to those found in other marine fish of temperate and tropical latitudes. The present study suggests that the composition of the parasite community is associated with the host feeding habits because 18/21 of the recorded species are trophically transmitted.

Dichelyne (Cucullanellus) tornquisti n. sp. is described from the intestine of the marine fish Orthopristis ruber (Haemulidae) of Rio de Janeiro, Brazil. The new species differs from the congeners by the location of the deirids (same level) and the excretory pore (posterior) in relation to esophagus-intestinal junction and by papillae 5 to 9 not forming a subventral line. It is the first Dichelyne species described from fish family Haemulidae in the Brazilian coastal zone.

Recent studies indicate that the northwestern Pacific Ocean is an ideal system in which to study and understand the roles of the Pleistocene sea-level fluctuations and ocean currents in shaping phylogeographic patterns of species, but most of these investigations have been concerned with vertebrates, and only a few have focused on invertebrates. In the present study, we examined the genetic population structure and historic demography of a platyhelminth species, Gotocotyla sawara (Monogenea, Gotocotylidae), a gill parasite of Japanese Spanish mackerel, Scomberomorus niphonius , along the coast of China. A fragment of the mitochondrial cytochrome oxidase I (COI) gene for 169 individuals and the internal transcribed spacers for 24 individuals were sequenced from specimens representing 8 populations of this parasite along the coast of China. High levels of COI haplotype diversity (0.9994) and nucleotide diversity (0.015805) were detected for G. sawara. Phylogenetic analysis revealed no phylogeographical pattern for G. sawara in the sample area. Analysis of molecular variance (AMOVA) revealed no significant differences at all hierarchical levels, and pairwise FST analysis demonstrated a high rate of gene flow of this parasite among different populations in coastal Chinese waters. Moreover, the exact test of differentiation supported the null hypothesis that G. sawara along the coast of China constitutes a panmictic population. Both neutrality tests and mismatch distribution revealed that G. sawara underwent population expansion in the late Pleistocene era. Recent range expansion after the last glacial maximum and insufficient time to attain migration-drift equilibrium may account in part for the lack of genetic structure in the geographic areas considered in this study. Dispersal of parasite eggs and larvae along ocean currents, coupled with the long-distance migrations of host fishes, could also be responsible for genetic homogeneity of this parasite. It is also possible that other hosts of this monogean, such as the ridged-eye flounder, Pleruonichthys cornutus, may contribute to the genetic mixing of Gotocotyla sawara populations.

Hysterothylacium thalassini Bruce, 1990, was redescribed using light microscopy and, for the first time, scanning electron microscopy based on newly collected specimens from the marine fishes Priacanthus tayenus Richardson and Pricanthus macracanthus Cuvier (Perciformes: Priacanthidae) in the South China Sea. Previously unreported or inaccurately described morphological features of taxonomic significance are described, including the number and morphology of paracloacal and postcloacal papillae, the morphology of the vulva, and the presence of small phasmids in the both sexes. Moreover, specimens of H. thalassini collected from the 2 hosts were characterized by sequencing and analyzing the internal transcribed spacer (ITS) of the ribosomal DNA. The ITS region of H. thalassini was compared with Hysterothylacium spp. in GenBank, and the results seem to support the validity of the incompletely known species.

This survey of parasites in 2 adjacent lakes is the first of its kind in the Adirondack Park of New York State. Wolf Lake is designated as a heritage lake whereas nearby Deer Lake is limnologically similar but has at least 5 introduced fish species. Both lakes have 2 native species, i.e., white sucker (Catostomus commersoni) and redbreast sunfish (Lepomis auritus), which were the focus of this study. Parasite communities of both hosts were surveyed and compared between each lake and were statistically evaluated for differences in species similarity, prevalence, mean intensity, and mean abundance. Between lakes, white suckers had significant differences in the prevalence of 4 parasite species (Myxobolus sp. 2, Myxobolus bibulatus, Octospinifer macilentis, and Pomphorhynchus bulbocoli) and mean abundances of 4 parasites (neascus larvae, Octospinifer macilentis, Pomphorhynchus bulbocoli, and Glaridacris confusus). Redbreast sunfish had significant differences in the prevalence of 3 species (Myxobolus uvuliferis, a coccidian species, and Spinitectus carolini) and differences in parasite mean abundance of 5 species (neascus larvae, Clinostomum marginatum , Leptorhynchoides thecatus, Spinitectus carolini, and Eustrongylides sp.). Differences in component communities between lakes were found and, although the exact causes cannot be determined by this study, we speculate on several possible explanations.

During a parasitological survey of naked gobies ( Gobiosoma bosc ) in Lake Pontchartrain, Louisiana, U.S.A., 2 myxozoan parasites were found infecting the gall bladders of 84 of 90 fish. Parasite plasmodia of each were morphologically distinct; plasmodia bearing Ellipsomyxa-like spores were elongate and fusiform (1,126 by 403 μm), and those bearing Sphaeromyxa-like spores were large and discoid (1,400 μm diameter). Neither parasite conformed to any described species of myxozoan, and both are described here. Sphaeromyxa kenti n. sp. bears boomerang-shaped spores ranging 17.5-19.8 μm long by 3.8-5.2 μm wide. Two unequal sized polar capsules contain ribbon-like polar filaments characteristic of this genus. Ellipsomyxa adlardi n. sp. bears ovoid spores 11.3-14.4 by 7.1-8.8 μm, with 2 rounded polar capsules oriented in opposite directions relative to the longitudinal plane of the spore. Phylogenetically both species cluster with sequenced members of their respective genera. Plasmodia of E. adlardi n. sp. were encountered in 72.2% of gobies examined, and S. kenti n. sp. in 25.6%. Overall, 6.7% of animals were uninfected, and only 4.4% of the 90 fish examined were infected with both species. The observed co-occurrence was lower than expected by chance, strongly suggestive of an interaction between these species.

A new species of monorchiid trematode, Leiomonorchis zhanjiangensis n. sp. (Trematoda: Monorchiidae), is described from the intestine of marine fish Secutor ruconius (Hamilton-Buchanan) (Leiognathidae) from Zhanjiang (21°2'N, 110°3'E), Guangdong Province, China. The new species is distinguished from all known species of the genus, mainly by the configuration of vitelline follicles and the shape of excretory bladder (saccular in the new species vs. tubular in the others). According to Madhavi's opinion, Caballerotrematoides secundus Ahmad, 1981 was transferred from Caballerotrematoides Madhavi, 1977 into Leiomonorchis Mamaev, 1970 as L. secundus (Ahmad, 1981) n. comb.

Macvicaria magellanica n. sp. (Digenea: Opecoelidae) is the third representative of this genus occurring in fish in the Magellanic sub-region of sub-Antarctica and the first one found in sub-coastal waters in this area (the Beagle Channel). Its main taxonomic features include an elongate body, oral:ventral sucker ratio based on widths of 1.0:1.52-1.98, cirrus sac reaching to level of posterior half of the ventral sucker, testes arranged in tandem, numerous vitelline follicles divided into 2 groups separated by a gap parallel to the ventral sucker, vitelline follicles dorsally not confluent at the uterus and gonads, and egg dimensions of 40-51 × 25-32 μm. The most similar species is Macvicaria antarctica, but it differs from the newly described species in having vitelline follicles dorsally confluent at the level of the uterus and by occurring in fish associated with the Falkland-Patagonian shelf at greater depths (at the North Scotia Ridge, 300-500 m). A key to 9 Antarctic and sub-Antarctic species of Macvicaria is included.

Eggs and larvae of Huffmanela oleumimica n. sp. infect red snapper, Lutjanus campechanus (Poey, 1860), were collected from the Texas-Louisiana Shelf (28°16'36.58″N, 93°03'51.08″W) and are herein described using light and scanning electron microscopy. Eggs in skin comprised fields (1-5 × 1-12 mm; 250 eggs/mm(2)) of variously oriented eggs deposited in dense patches or in scribble-like tracks. Eggs had clear (larvae indistinct, principally vitelline material), amber (developing larvae present) or brown (fully developed larvae present; little, or no, vitelline material) shells and measured 46-54 μm (x = 50; SD ± 1.6; n = 213) long, 23-33 (27 ± 1.4; 213) wide, 2-3 (3 ± 0.5; 213) in eggshell thickness, 18-25 (21 ± 1.1; 213) in vitelline mass width, and 36-42 (39 ± 1.1; 213) in vitelline mass length with protruding polar plugs 5-9 (7 ± 0.6; 213) long and 5-8 (6 ± 0.5; 213) wide. Fully developed larvae were 160-201 (176 ± 7.9) long and 7-8 (7 ± 0.5) wide, had transverse cuticular ridges, and were emerging from some eggs within and beneath epidermis. The new species differs from its congeners by having eggs <65 μm in total length and that have a brown eggshell when fully developed, an envelope throughout development, and irregularly-dispersed eggshell spines plus a larva >110 μm long with transverse cuticular ridges. The eggs lack a spindle-shaped envelope, polar filaments, and eggshell ridges. This is the first report of a species of Huffmanela from a snapper (Lutjanidae) or from the Gulf of Mexico. A table of egg and larval characteristics, hosts, and localities for Huffmanela spp. is provided.

A new nematode species, Philometra atlantica n. sp. (Philometridae), is described from male and female specimens found in the ovary of the Atlantic Spanish mackerel, Scomberomorus maculatus (Mitchill) (Scombridae, Perciformes), off the Atlantic coast of Florida and South Carolina. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (111-126 μm), number and arrangement of genital papillae, and a U-shaped, dorsally interrupted caudal mound in the male. A unique feature among all gonad-infecting philometrids is the presence of 2 reflexed dorsal barbs on the distal end of the gubernaculum. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid females (body length, length of first-stage larvae or esophagus, structure of caudal end) and by the host type (fish family) and geographical distribution. Philometra atlantica is the fourth valid gonad-infecting species of Philometra reported from fishes of the family Scombridae.

Homalometron palmeri n. sp. is described and reported from the following fishes in the northern Gulf of Mexico: Micropogonias undulatus, Sciaenops ocellatus, Bairdiella chrysoura, Pogonias cromis, Fundulus grandis, Fundulus similis, and Eucinostomus argenteus. This species historically has been misidentified as Homalometron pallidum by some, and treated as Homalometron sp. by others. The new species differs from H. manteri by having a smaller body size, relatively longer postcecal space ranging from 7 to 15% of body length compared with 6-8%, body spines from 12 to 17 μm long compared with 15-20 μm, and an oral-to-ventral sucker width ratio of 1:1.2-1.3 compared with 1:1.3-1.5. Ribosomal DNA sequences from H. palmeri n. sp., H. pallidum, Homalometron manteri, and Homalometron pseudopallidum are compared and the new species is found to be most similar to H. manteri, a sympatric species. Comparison between 2 mitochondrial genes from H. palmeri n. sp. and H. manteri provided further evidence for their status as distinct species. Pairwise comparison of 503 aligned bases from ND1 gene revealed 33 variable sites (6.5%) between the 2 species. Pairwise comparison of 1,152 aligned bases from COI gene revealed 73 variable sites (6.3%) between the 2 species. Interspecific variability in mitochondrial sequences between the 2 species was 3-16 times greater than intraspecific variability in either species.

A new species of Grillotia was found from teleosts and elasmobranchs along the Patagonian shelf off Argentina. Grillotia patagonica n. sp. is described from plerocerci recovered from gadiform (Moridae) and perciform fish (Cheilodactylidae, Bovichtidae, and Nototheniidae) and adults from the smallthorn sand skate Psammobatis rudis (Rajiformes, Rajidae). Grillotia patagonica most closely resembles species in the Grillotia erinaceus species complex (viz., Grillotia borealis, Grillotia brayi, Grillotia dollfusi, G. erinaceus, and Grillotia musculara) in having 4 hooks per principal row and 2 or more intercalary rows in the metabasal region, a band of hooks on the external surface of the tentacle, numerous proglottids, a hermaphroditic sac, internal and external seminal vesicles, uterine pore, and attachment of the retractor muscle in the mid region of the tentacular bulb. Grillotia patagonica n. sp. is unique among all valid species in the genus by having the hooks on the first row reduced and of a different shape from the rest of the metabasal rows. Despite the diversity of elasmobranchs that are available as definitive hosts for species in Grillotia, most species (10/14) are oioxenous or mesostenoxenous. The specificity for the last intermediate host is variable among species of Grillotia, with most plerocerci being oioxenous (5/15) or euryxenous (8/15). Host specificity is higher for the adult stage in the definitive host (mean HS(S) = 4.07) than for the plerocerci (mean HS(S) = 7.30). All the species with oioxenous specificity (either larvae or adults) have limited geographic distributions. Some previous records of species of Grillotia from fishes caught off Argentina require reconsideration, i.e., G. erinaceus, Grillotia minuta (reported as Grillotia bothridiopunctata) and G. borealis . An updated host-parasite checklist for the valid species of Grillotia is also presented along with new host records for Grillotia carvajalregorum.

Primisanguis caribbeanensis n. gen., n. sp. (Digenea: Aporocotylidae) infects the stoplight parrotfish, Sparisoma viride (Bonnaterre, 1788), (Labridae: Scarinae) in the Caribbean Sea off La Parguera (17°58'26" N, 67°02'47"W), Puerto Rico. It is most easily distinguished from other nominal aporocotylids by the combination of having an adult body that is approximately 5-10 times longer than wide, a sinistral posterolateral body protuberance, tegumental body spines that are straight (lacking recurved tip) and wrap dorsoventrally around the body margin, posterior ceca that are 2-5 times the anterior ceca length, a single testis that extends lateral to both the ceca and nerve cords, an ovary abutting the posterior margin of the testis, a symmetrical vitellarium and medial primary vitelline duct, a post-cecal and post-gonadal ootype, and a proximal uterus that is extensively convoluted posterior to the ootype and which functions as a uterine seminal receptacle. The new genus lacks a spinous anterior sucker, pharynx, auxiliary external seminal vesicle, cirrus stylet, oviducal seminal receptacle, and Laurer's canal. The new species is morphologically most similar to the other aporocotylids that have a posterolateral body protuberance, including species of Psettarium Goto and Ozaki, 1930, Aporocotyle Odhner, 1900, Ankistromeces Nolan and Cribb, 2004 , Phthinomita Nolan and Cribb, 2006, and Littorellicola Bullard, 2010, but it can be differentiated from them, at the least, by lack of a spinous anterior sucker in the adult and by the combination of having dorsoventral rows of tegumental spines, a testis dorsal to the posterior ceca, and a uterine seminal receptacle posterior to the ootype. The new species is the first aporocotylid reported from the Caribbean Sea or from a parrotfish of Sparisoma.

Vitellogenesis of Aphallus tubarium, an intestinal parasite of Sparidae (Dentex dentex ), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiéry method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.

Specimens of a capsalid collected from the gill arches of 2 roundscale spearfish, Tetrapturus georgii Lowe, 1840, (Perciformes: Istiophoridae), captured in the northwestern Atlantic Ocean were identified as Capsala laevis (Verrill, 1875) Johnston, 1929 by having the combination of papillae on the ventral surface of haptor, dorsomarginal body sclerites in a single column extending the entire body length, haptoral accessory sclerites, conical papillae distributing over the ventral body surface, and an anterior attachment organ with a fimbriated posterior margin. The new specimens plus the holotype were used to conduct a taxonomic redescription of C. laevis using light and scanning electron microscopy. We documented that the holotype (USNPC No. 7179) and the new specimens of C. laevis from roundscale spearfish each had papillae on the ventral surface of the anterior attachment organs and sensory papillae on the dorsal body surface. Although data are insufficient at this time to justify proposal of a new species, the new specimens differed from the holotype and published accounts of C. laevis by having a sinistral dorsomarginal patch comprising 27-35 sclerites whereas the holotype has a dorsomarginal patch comprising 60 sclerites. Capsala laevis morphologically most closely resembles Capsala ovalis (Goto, 1894) Price, 1938 , but can be most easily differentiated from it by having dorsomarginal body sclerites. This represents the first record of any parasite from the recently taxonomically resurrected roundscale spearfish, long considered by some as a junior subjective synonym of white marlin, Tetrapturus albidus Poey, 1860 and, concomitantly, a new host record for Capsalidae Baird, 1853. An updated list of host records for C. laevis is provided. A perusal of that literature reveals that the identity of the type host for C. laevis is indeterminate beyond Istiophoridae species and that subsequent reports of the type host as ' T. albidus ' are presumptuous (originally reported in 1875 by Verrill as "bill-fish" only). Our results indicated that 2 records of C. laevis from the swordfish, Xiphias gladius Linnaeus, 1758, (Perciformes: Xiphiidae) are dubious, i.e., study of the museum voucher USNPC No. 8154 indicates that Linton's 1940 record from the northwestern Atlantic Ocean likely represents a new species of Capsala Bosc, 1811 and that the Kayiş et al. 2010 record from the Aegean Sea likely depicts a species of Capsaloides Price, 1938.

Collections of giant kelpfish at inner Cabrillo Beach, San Pedro, California revealed the presence of an undescribed species of Heptacyclus, described here as Heptacyclus cabrilloi n. sp. The leech is small, only up to 14 mm total length including suckers; it has 2 pair of slightly crescentiform eyes on the oral sucker, 1 pair of punctiform ocelli on the second annulus of the trachelosome, 13 pairs of punctiform ocelli dorsally and ventrally on the urosome, and 14 marginal punctiform ocelli on the caudal sucker. Pigmentation is yellowish-tan with an unpigmented mid-dorsal stripe on both trachelosome and urosome, and with unpigmented halos around eyespots and urosome ocelli. Male reproductive system with 5 pairs of large, spherical testisacs. Mycetomes present, accessory gland cells on atrial cornu absent. Prevalence was 24.1% in June, 2011 with a range of 1-2 leeches per fish and 25.8% in October, 2011 with a range of 1-6 leeches per fish.

Biological invasions are considered a major threat to biodiversity around the world, but the role of parasites in this process is still little investigated. Here, we compared parasite infections of a host species in the areas where it originated and where it was introduced, and in native and introduced species in the same environment, using the endoparasites of the fish Plagioscion squamosissimus (Sciaenidae) in 3 Brazilian basins. Samples were taken in 2 rivers where the species is native, i.e., Solimões River (SO) and Tocantins River (TO), and where the species was introduced, the upper Paraná River (PR). In addition, abundances of diplostomids and larval nematodes were compared between P. squamosissimus and 2 native competitors in the PR, Hoplias malabaricus and Raphiodon vulpinus. In total, 13 species of endoparasites were recorded, but only Austrodiplostomum sp. and cestode cysts were present in all localities. Although infracommunity richness was similar, their species composition was slightly different among localities. General linear models using the relative condition factor of fish as response variables, and abundance of the most prevalent parasites as possible predictors showed that the condition of fish is negatively correlated with parasite abundance only in the native range (TO). Abundance of diplostomid eye flukes was higher in the PR, and in the native species H. malabaricus when compared to the invader, which might present an advantage for P. squamosissimus if they compete for prey. However, although P. squamosissimus may have lost some of its native parasites during its introduction to the PR, it is now possibly acting as a host for native generalist parasites.

Flier (Centrarchus macropterus: Centrarchidae) were collected from a channel habitat, a prairie habitat, and a boundary between the 2 habitat types in March 2009 and examined for parasites. Flier from the prairie site had a significantly lower abundance of Pterocleidus acer and a significantly higher abundance of Hysterothylaceum juveniles. Patterns of infracommunity similarity showed a distinct break between the 2 habitat types, with fish collected from the boundary site clustering with either channel or prairie communities, suggesting that the small home range of flier restricts the exposure of individuals to parasites.

We assessed temporal variability in parasite infections of rough scad (Trachurus lathami) in 3 samples from Miramar (MI) in 2008, separated by periods of 1 mo, and 2 samples from Villa Gesell (VG), 1 each in 2008 and 2009 (Buenos Aires Province, Argentina), respectively. A sample was also obtained from Cabo Frio (CF) (Brazil) in 2009 to compare differences in parasite communities between fish from this locality and each Argentinean locality. All rough scad were parasitized by at least 1 of 27 parasite species. Similarity-based multivariate analysis revealed significant differences between localities, but temporal homogeneity in each Argentinean locality. Overall, prevalence and abundance of parasite species were most similar between samples from MI and VG, while the greatest differences occurred between samples from MI and CF. A canonical analysis of principal coordinates showed significant differences among samples. Grillotia carvajalregorum was the most important species in determining the position of Argentinean samples, especially those from MI, while Ectenurus virgulus , Raphidascaris sp., and Hysterothylacium sp. were the most important species related to fish from CF. The parasite assemblage of T. lathami showed a notable temporal persistence within the same locality and a high variability at the spatial scale, suggesting the existence of 3 independent stocks of T. lathami in South Atlantic waters.

The mature spermatozoon of Bothriocotyle sp. is filiform and tapered at both extremities. It possesses 2 axonemes of unequal length, showing the 9 + "1" pattern of Trepaxonemata. The anterior extremity exhibits a crest-like body. Thereafter, the crest-like body disappears, and the first axoneme is surrounded by a ring of cortical microtubules (about 27 units) that persist until the appearance of the second axoneme. This ring of cortical microtubules is characteristic only for species of Bothriocephalidea and represents a very useful phylogenetic character. The spermatozoon cytoplasm is slightly electron-dense and contains numerous electron-dense granules of glycogen in several regions. The anterior and posterior extremities of the spermatozoon lack cortical microtubules. The posterior extremity of the spermatozoon of Bothriocotyle sp. possesses a nucleus and a disorganized axoneme, which also characterizes spermatozoa of the Echinophallidae studied to date.