Smaller Proboscis Research Articles

Descriptions of two new acanthocephalans (Rhadinorhynchidae) from marine fish off the Pacific coast of Vietnam.

Two rhadinorhynchid acanthocephalans are described from marine fishes off the Pacific coast of Vietnam. Sclerocollum neorubrimaris n. sp. (Gorgorhynchinae Van Cleave & Lincicome, 1940) is described from the spine-foot rabbitfish Siganus guttatus (Bloch) (Siganidae) off Nha Trang. The new species is similar to the type-species, Sclerocollum rubrimaris Schmidt & Paperna, 1978 in most measurements and counts but has a posterior cephalic ganglion, a sub-ventral female gonopore, and one dorsal paravaginal filament bundle. In S. rubrimaris, the cephalic ganglion is near the middle of the receptacle, the female gonopore is terminal with two paravaginal filament bundles. The new species is distinguished from three other species of Sclerocollum Schmidt & Paperna, 1978 in proboscis hook formulas and the position of the female gonopore and cephalic ganglion. The issue of the importance of the position of the cephalic ganglion at the generic and sub-generic levels in the Acanthocephala is discussed. Females of Australorhynchus multispinosus n. sp. (Gorgorhynchinae) are described from the red cornetfish Fistularia petimba Lacépède off Nha Trang in the Pacific south. It is distinguished from the only other species of the genus, Australorhynchus tetramorphacanthus Lebedev, 1967, by having more trunk spines extending beyond the level of the proboscis receptacle and a smaller proboscis with considerably fewer hooks.

Mayarhynchus karlae n. g., n. sp. (Acanthocephala: Neoechinorhynchidae), a parasite of cichlids (Perciformes: Cichlidae) in southeastern Mexico, with comments on the paraphyly of Neoechinorhynchus Stiles & Hassall, 1905.

Mayarhynchus n. g. (Acanthocephala: Neoechinorhynchidae) is erected for Mayarhynchus karlae n. g, n. sp. described from the intestine of four species of cichlid fishes distributed from southeastern Mexico. The new genus placed in the family Neoechinorhynchidae (Ward, 1917) Van Cleave, 1928, is readily distinguished from the other 17 genera in the family by having a small proboscis armed with 45-46 relatively weak rooted hooks arranged in nine longitudinal rows of five hooks each. In addition, Mayarhynchus n. g., n. sp. is diagnosed by the presence of a short trunk, body wall with five dorsal and one ventral giant hypodermal nuclei, proboscis receptacle nearly cylindrical with single layered wall, lemnisci broad and flat with large nuclei, testes in tandem, cement gland with eight large nuclei, and eggs elongate to oval. Partial sequences of the cytochrome c oxidase subunit 1 (cox1), internal transcribed spacers (ITS1+5.8S+ITS2), and the D2-D3 domains of the large subunit rRNA gene (28S) were obtained for five specimens of the new species and other species belonging to the Neoechinorhynchidae. Phylogenetic analyses confirmed that the new genus belongs to the Neoechynorhynchidae and indicated that the genus Neoechynorhynchus Stiles & Hassall, 1905 is not monophyletic. Comparison between three populations of the new species yielded nine variable sites for cox1, 11 for ITS and four for 28S.

Morphological and molecular descriptions of Moniliformis saudi sp. n. (Acanthocephala: Moniliformidae) from the desert hedgehog, Paraechinus aethiopicus (Ehrenberg) in Saudi Arabia, with a key to species and notes on histopathology

A new acanthocepohalan species, Moniliformis saudi sp. n. is described from the desert hedgehog, Paraechinus aethiopicus (Ehrenberg), in central Saudi Arabia. Fourteen other valid species of Moniliformis Travassos, 1915 are recognised. The new species of Moniliformis is distinguished by having a small proboscis (315-520 µm long and 130-208 µm wide) with two apical pores, 14 rows of 8 hooks each and small hooks, thre largest being 25-31 µm long anteriorly. Distinguishing features are incorporated in a dichotomous key to the species of Moniliformis. The description is augmented by scanning electron microscopical (SEM) observation and DNA analysis of nuclear (18S rRNA) and mitochondrial (cytochrome oxidase subunit 1; cox1) gene sequences. Attached worms cause extensive damage to the immediate area of attachment in the host intestine. This includes tissue necrosis and blood loss due to damage to capillary beds. Worms also obstruct essential absorbing surfaces.

Формирование современного облика медоносных пчел и их воспроизводство в Республике Дагестан

Grey mountain Caucasian bees are of great interest for the selection, as a valuable gene pool of different populations of this race is supported by high mountains and inaccessible gorges of Dagestan, while serving as an isolated mountainous natural breeding areas. The studies were conducted in three different climatic conditions of the republic: the plains, foothills and mountainous areas. In the area of natural dispersal of gray mountain Caucasian bees in Dagestan released several local populations and different backgrounds. Characteristics of the main morphological features of honey bees are the length of proboscis, wing and width of the third tergite and others. These features bees vary, depending on the habitat population. Numerous studies of Dagestan honeybees showed, that the longest proboscis inherent in bees of mountain zone (6.85 ± 0.03 mm). The plain bees have a smaller proboscis (up to 6.71 ± 0.01 mm), and in the foothills bees the proboscis occupies an intermediate position (from 6.69 ± 0.01 to 6.83 ± 0.01 mm). Two other peculiarities (wing length and the third tergite) are subject to variation, depending on the altitude above sea level.

Morphological and molecular data reveal a new species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) from Dormitator maculatus in the Gulf of Mexico

Neoechinorhynchus (Neoechinorhynchus) mexicoensis sp. n. is described from the intestine of Dormitator maculatus (Bloch 1792) collected in 5 coastal localities from the Gulf of Mexico. The new species is mainly distinguished from the other 33 described species of Neoechinorhynchus from the Americas associated with freshwater, marine and brackish fishes by having smaller middle and posterior hooks and possessing a small proboscis with three rows of six hooks each, apical hooks longer than other hooks and extending to the same level as the posterior hooks, 1 giant nucleus in the ventral body wall and females with eggs longer than other congeneric species. Sequences of the internal transcribed spacer (ITS) and the large subunit (LSU) of ribosomal DNA including the domain D2+D3 were used independently to corroborate the morphological distinction among the new species and other congeneric species associated with freshwater and brackish water fish from Mexico. The genetic divergence estimated among congeneric species ranged from 7.34 to 44% for ITS and from 1.65 to 32.9% for LSU. Maximum likelihood and Bayesian inference analyses with each dataset showed that the 25 specimens analyzed from 5 localities of the coast of the Gulf of Mexico parasitizing D. maculatus represent an independent clade with strong bootstrap support and posterior probabilities. The morphological evidence, plus the monophyly in the phylogenetic analyses, indicates that the acanthocephalans collected from intestine of D. maculatus from the Gulf of Mexico represent a new species, herein named N. (N.) mexicoensis sp. n.

Description of a new species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) a parasite of Dormitator latifrons from Southwestern Mexico based on morphological and molecular characters

Neoechinorhynchus mamesi n. sp. is described from the estuarine fish Dormitator latifrons collected in 3 localities along the coast of Chiapas State in Southwestern Mexico. The new species is characterized by possessing a small trunk, a very small proboscis with relatively very long apical proboscis hooks and small middle and posterior hooks, 2 giant nuclei in the ventral body wall, and males with testes smaller than the cement gland. A multivariate analysis of variance (MANOVA) and a Principal Component Analysis (PCA) of 46 morphometric traits for 21 mature females and 18 males of N. mamesi n. sp., N. brentnickoli and N. golvani, revealed morphological variation among species. DNA sequences of 2 genes, cytochrome oxidase subunit 1 (cox 1) of the mitochondrial DNA and the domains D2 and D3 of the large subunit of the nuclear ribosomal RNA (LSU) were used to corroborate the morphological distinction. The genetic divergence estimated among populations of N. brentnickoli and N. mamesi n. sp. ranged from 10.14 to 10.55% for LSU and from 20.53 to 22.06% for cox 1, whereas the genetic divergence between N. golvani and N. mamesi n. sp. ranged from 20.31 to 21.03% for LSU and from 22.24 to 24.95% for cox 1. Maximum likelihood, maximum parsimony and Bayesian inference analyses were performed for the combined data sets (LSU+cox 1) and each data set alone. All the phylogenetic analyses showed that the specimens from 3 coastal lagoons of Chiapas State in Southwestern Mexico represented a monophyletic clade with strong bootstrap support and Bayesian posterior probabilities. The haplotype network based on the analysis of the cox 1 sequences indicated that N. mamesi n. sp. is separated by 84 substitutions from N. brentnickoli, and with 69 substitutions from N. golvani. The morphological evidence, the multivariate analyses, in combination with the genetic divergence estimated with two genes, the reciprocal monophyly in all the phylogenetic analyses, and the haplotype network, suggested that the acanthocephalans found in the intestine of D. latifrons in Southwestern Mexico represent a new species, named N. mamesi n. sp., and it constitutes the second species of the genus Neoechinorhynchus associated with the Pacific fat sleeper along the Pacific Coast of Mexico.

Morphology of a new deep‐sea acorn worm (class Enteropneusta, phylum Hemichordata): A part‐time demersal drifter with externalized ovaries

Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific--one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho-pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome-shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow-living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate-like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus.

A New Species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) in Dormitator latifrons (Perciformes: Eleotridae) from the Pacific Coast of Mexico

Neoechinorhynchus brentnickoli n. sp. is described from specimens of Dormitator latifrons (Pacific fat sleeper) collected from 3 localities along the Pacific Coast of México: Tres Palos Lagoon (Guerrero State), Bahía de Chamela (Jalisco State), and Mazatlán (Sinaloa State), México. Of the 3 members of the genus known from Mexican fish, the new species is more similar to Neoechinorhynchus golvani Salgado-Maldonado, 1978, than to Neoechinorhynchus roseus Salgado-Maldonado, 1978, or Neoechinorhynchus chimalapasensis Salgado-Maldonado, Caspeta-Mandujano, and Martínez-Ramírez, 2010. Neoechinorhynchus brentnickoli n. sp. can be distinguished from N. golvani in being longer and having more dimorphism between trunk length of males and females, a different number of ventral giant nuclei (2 vs. 1), smaller proboscis, shorter hooks in all 3 circles, a longer receptacle, and larger testes and cement gland. The anterior portion of the trunk wall of the new species is more delicate than that of the rest of the trunk, and it can be inverted into the body cavity in a manner similar to the way in which the proboscis is inverted into the receptacle. Previous studies that attributed specimens of this species to N. golvani are discussed.

Helminth parasites from Red Sea fishes: Neowardula brayi gen. nov., sp. nov. (Trematoda: Mesometridae Poche, 1926) and Sclerocollum saudii sp. nov. (Acanthocephala: Cavisomidae Meyer, 1932)

Specimens of the fishes Acanthopagrus bifasciatus Forsskål (Sparidae) and Siganus rivulatus Forsskål (Siganidae) were caught in the Red Sea off the coast of Rabigh, Saudi Arabia. Four (25%) and 24 (80%) of these fishes, respectively, were found to harbour intestinal helminths. Acanthopagrus bifasciatus was parasitised by Neowardula brayi gen. nov., sp. nov. (Trematoda: Mesometridae) and S. rivulatus by Sclerocollum saudii sp. nov. (Acanthocephala: Cavisomidae). Neowardula brayi gen. nov. is similar to Wardula Poche, 1926, but clearly differs from it and from the other four genera of the family Mesometridae Poche, 1926 in having a ventral surface anterior to the intestinal bifurcation greatly modified into a well-developed, relatively deep pouch encircling the genital pore and constantly diagonal testes. Sclerocollum saudii sp. nov. is similar to S. rubrimaris Schmidt et Paprena, 1978 (type species), but clearly differs in having a proboscis only armed with 10 rows of hooks, smaller proboscis hooks, lemnisci much longer than proboscis receptacle and much smaller egg size. The developmental stages of this acanthocephalan (cystacanths, juveniles and immature worms) are also described and figured.

Anterior regeneration in the hemichordate Ptychodera flava

Ptychodera flava is a hemichordate whose anterior structures regenerate reproducibly from posterior trunk pieces when amputated. We characterized the cellular processes of anterior regeneration with respect to programmed cell death and cell proliferation, after wound healing. We found scattered proliferating cells at day 2 of regeneration using a proliferating cell nuclear antigen antibody. On day 4, most proliferating cells were associated with the nerve tract under the epidermis, and on day 6, a small proboscis derived from proliferated cells was regenerated, and a mouth had broken though the epidermis. TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling) detected elevated levels of apoptosis in the endoderm that began furthest away from the region of wound healing, then moved anteriorly over 8 days. Posterior to anterior apoptosis is likely to remove digestive endoderm for later differentiation of pharyngeal endoderm. We hypothesize that P. flava regeneration is nerve dependent and that remodeling in the gut endoderm plays an important role in regeneration.

Cystacanths of Acanthocephala in notothenioid fish from the Beagle Channel (sub-Antarctica)

The morphology of relaxed cystacanths of polymorphid acanthocephalans collected from notothenioid fishes in the Beagle Channel (Magellanic subregion of sub-Antarctica) is described. A parasite of birds, Andracantha baylisi (Zdzitowiecki, 1986), was found in Patagonotothen longipes and Champsocephalus esox. It has: a proboscis 0.82-0.89 mm long; a proboscis hook formula of 16 rows of 9/10-10/11, including 4-5 basal hooks; distal hooks with the longest blades; a fore-trunk not separated from the hind-trunk by a constriction; large somatic spines arranged in two zones separated by a zone of small, loosely dispersed spines; and only the anterior 36-40% of ventral side of the trunk is covered with spines. One male specimen of Corynosoma sp. was found in Patagonotothen tessellata. It differs from A. baylisi in that the distal proboscis hooks are similar in length to the prebasal hooks, it has a smaller proboscis (0.77 mm) and in the distribution of the somatic spines, which are contiguous with the genital spines on the ventral side of the trunk and lack a zone of small spines between zones of larger spines. A parasite of seals and fur seals, Corynosoma evae Zdzitowiecki, 1984, was found in P. longipes and Champsocephalus esox. It has: a proboscis 0.61-0.78 mm long; a proboscis hook formula of 20-22 rows of 12-13, including 3/4-4 basal hooks; prebasal hooks with the longest blades; a trunk divided into fore-trunk and hind-trunk; somatic spines covering the anterior 64-74% of the ventral side of the trunk; genital spines present only in males; and a terminal genital opening in both sexes. Corynosoma beaglense n. sp. was found in Champsocephalus esox. It has: an almost cylindrical proboscis (length 0.52-0.56 mm); a proboscis hook formula of 16 rows of 9/10-10/11, including 4-4/5 basal hooks; distal hooks shorter than the prebasal hooks; a fore-trunk not separated from the hind-trunk by a constriction; somatic spines contiguous with the genital spines on the ventral side of the trunk of the male and covering the entire length of the ventral side of the female trunk, and the presence of genital spines surrounding the terminal genital pore of the male. The definitive host of this species is unknown.

Olfactory conditioning of proboscis activity in Drosophila melanogaster

Olfactory learning and memory processes in Drosophila have been well investigated with aversive conditioning, but appetitive conditioning has rarely been documented. Here, we report for the first time individual olfactory conditioning of proboscis activity in restrained Drosophila melanogaster. The protocol was adapted from those developed for proboscis extension conditioning in the honeybee Apis mellifera. After establishing a scale of small proboscis movements necessary to characterize responses to olfactory stimulation, we applied Pavlovian conditioning, with five trials consisting of paired presentation of a banana odour and a sucrose reward. Drosophila showed conditioned proboscis activity to the odour, with a twofold increase of percentage of responses after the first trial. No change occurred in flies experiencing unpaired presentations of the stimuli, confirming an associative basis for this form of olfactory learning. The adenylyl cyclase mutant rutabaga did not exhibit learning in this paradigm. This protocol generated at least a short-term memory of 15 min, but no significant associative memory was detected at 1 h. We also showed that learning performance was dependent on food motivation, by comparing flies subjected to different starvation regimes.

Porrorchis nickoli n. sp. (Acanthocephala:: Plagiorhynchidae) from mammals in southeastern Mexico, first known occurrence of Porrorchis in the western hemisphere.

Porrorchis nickoli n. sp. is described from the intestine of the gray four-eyed opossum Philander opossum (type host), the Virginia opossum Didelphis virginiana, the common opossum Didelphis marsupialis, and the white-nosed coati Nasua narica. Hosts were collected in southeastern Mexico in the Los Tuxtlas region of the state of Veracruz (type locality) and in the states of Tabasco and Chiapas. This new species is distinguished from other Porrorchis species by its small proboscis (0.286-0.428 mm long x 0.273-0.438 mm wide), a proboscis armature consisting of 22-24 vertical rows of 7 or 8 hooks per row, and the male reproductive system extending postequatorially and occupying only half of the trunk. This is the first known occurrence of a Porrorchis species in the Western Hemisphere.

OVICIDES JULIEAE N. GEN., N. SP. (NEMERTEA: CARCINONEMERTIDAE) ON XANTHID CRABS FROM THE GREAT BARRIER REEF, AUSTRALIA

A new genus and species of symbiotic, semi-parasitic nemertean worm, Ovicides julieae n. gen., n. sp., is described from the xanthid crabs Chlorodiella nigra and C. xishaensis. The new genus possesses accessory stylet pouches and exhibits simultaneous hermaphroditism, features new to the family Carcinonemertidae. The new species has a relatively small anterior proboscis chamber and small basis, yet it possesses the largest stylet to basis ratio (up to 0.650) reported for the family. It also has a flame cell pattern of at least 2[(3+3)], which is different from those reported for two other species. The worm occurred in a lightly granulated sheath on the abdominal sterna, pleopods, and clutches of its host, but few adult worms were found. The species exhibited a high host specificity and was more frequently found on C. nigra than on C. xishaensis (7.5 vs. 0.4%, overall prevalence, respectively). Worms were only found on female crabs, and worm intensity showed a modest but significantly positive correlation with host size. Ovicides julieae represents the second genus in the Carcinonemertidae, the fifth described carcinonemertid species from Australia, and the eleventh described species in the family.

Description of Neoechinorhynchus carinatus n. sp. (Acanthocephala: Neoechinorhynchidae) from the Sharpfin Chubsucker, Erimyzon tenuis, of Louisiana and Mississippi

Neoechinorhynchis carinatus n. sp. is described from Erimyzon tenuis (Agassiz) from southern Louisiana and Mississippi. Neoechinorhynchus carinatus is distinguished from other Neoechinorhynchus species, with unequal lemnisci, of North American freshwater fishes by having a dorsal body wall that is usually 2-3× thicker than the ventral body wall and small proboscis hooks with lateral hooks of the anterior circle being the largest and hooks of the middle and posterior circles about equal in length

Acanthocephalus tahlequahensis sp. n. (Acanthocephala: Echinorhynchidae) from the Stippled Darter, Etheostoma punctulatum (Agassiz), in Northeastern Oklahoma

Acanthocephalus tahlequahensis sp. n. was recovered from the intestines of 4 species of freshwater fishes, Etheostoma punctulatum, E. spectabile, Nocomis asper, and Notropis pilsbryi, collected in northeastern Oklahoma. The new species is distinguished from all other species of Acanthocephalus, except A. japonicus (Fukui and Morisita 1936) Petrochenko 1956, and A. fluviatilus Paperna 1964, by having smaller proboscis hooks. The length of the proboscis hooks for males is 27 to 38 (33) mum and for females 35 to 46 (42) mum. A. tahlequahensis is smaller than either A. japonicus or A. fluviatilis, and has about half the number of longitudinal rows of proboscis hooks of A. japonicus and half the number of proboscis hooks in each longitudinal row of A. fluviatilus. In addition to having smaller hooks. A. tahlequahensis differs from other species of Acanthocephalus parasitizing North American fishes by its smaller, spindle-shaped trunk and more hooks in each longitudinal row.

Acanthocephala in the flatfish Solea bleekeri (Soleidae) from Cape Province, South Africa.

AbstractTwo species of palaeacanthocephalan from Solea bleekeri from estuarine waters in Cape Province, South Africa, are described. Rhaidinorhynchus capensis sp. npv. differs from its closest relatives in having a smaller proboscis and in having body-spines arranged in a single field. Longicollum sp. innom., described from a single male specimen, differs from other species of the genus in having a basal row of large proboscis hooks and in having a recurved proboscis-sac.The two species of palaeacanthocephalans described in this report were collected from Solea bleekeri Boulenger, 1898, in estuarine waters in the southern-most region of Cape Province and donated to the British Museum (Natural History) by Professor John H. Day of the Zoology Department, University of Cape Town. Co-infestations did not occur, nor were both species found in the same immediate geographical area. The coastal region of Cape Province, from Algoa Bay in the east, to Cape Agulhas or Cape Point in the west, constitutes, according to Ekman (1953), an independent zoogeographical province, and, therefore, data on the parasitic worms of the marine fish of this region, which at the moment are exceedingly meagre, may be of interest and importance as indicators of the affinities of the fish stocks inhabiting this area.

Two New Acanthocephalans from Neotropical Fishes: Neoechinorhynchus prochilodorum sp. n. and Gorytocephalus plecostomorum gen. et sp. n.

Dying bocachicos, Prochilodus reticulatus, from the Sonso Reservoir at Valle, Colombia, were infected with Neoechinorhynchus prochilodorum sp. n. The new species has a proboscis which averages 83 , long. Hooks of the apical circle are 55 t, long, those of the middle circle 41, and those of basal circle 30. N. prochilodorum is distinguished from all previously described species of Neoechino- rhynchus except N. coiliae Yamaguti, 1939, and N. hutchinsoni Datta, 1936, by its proboscis hook lengths and its small proboscis. N. prochilodorum has a shorter, stouter trunk with a shorter neck and longer lemnisci than N. coiliae. Lack of sexual dimorphism in body size, lack of a trunk construction in males, and possession of lemnisci that reach the level of the anterior testis distinguish N. prochilodorum from N. hutchinsoni. Five of 7 specimens of the armored catfish, Plecostomus plecostomus, collected from the Rio Cardenas, Panama, R. P., were infected with from 1 to 7 specimens of Gorytocephalus plecostomorum gen. et sp. n. Gorytocephalus is a member of the subfamily Neoechinorhynchinae of the family Neo- echinorhynchidae. It differs from other genera of the subfamily in possession of a prominent muscular sling surrounding the proboscis receptacle and by the arrangement of the proboscis hooks. Goryto- cephalus plecostomorum is also characterized by a tall (750 ,) dorsal crest extending the entire length of the trunk. Neoechinorhynchus spectabilis Machado, 1959, is tentatively assigned to Gorytocephalus.

Pomphorhynchus rocci sp. n. (Acanthocephala) from the Rock Bass, Roccus saxatilis

The new species, found in two of three rock bass from the coastal region of North Carolina, is described and compared with other species of Pomphorhynchus. It differs from them in having 15 to 18 proboscis hooks in each longitudinal row. Other species have a maximum of 14 hooks in each longitudinal row. Viscera of three rock bass, Roccus saxatilis, from Elizabeth City, North Carolina, were obtained from a Knoxville fish market and examined for parasites. A number of small brown knobs were observed on the peritoneal side of the intestines of two fish. After opening the intestine it was found that the protrusions were caused by acanthocephalan proboscides that had penetrated the intestinal wall and had become covered with a thick layer of host tissue. The envelope of host tissue enclosed a bulbous swelling of the acanthocephalan neck in addition to the small proboscis. The parasites were recognized as members of the genus Pomphorhynchus and 12 worms were collected and prepared for microscopic study. These parasites differ from previously described species of this genus in that the number of proboscis hooks in each longitudinal row is 15 to 18, the maximum number being 14 in other species. They are therefore described here as a new species. Measurements are in microns unless otherwise indicated. Pomphorhynchus rocci sp. n. (Figs. 1-4)