University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications from the Harold W. Manter Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of 1992 Microphallus fonti sp. n. (Digenea: Microphallidae) from the Red Swamp Crawfish in Southern United States Robin M. Overstreet Gulf Coast Research Laboratory, [email protected] Richard W. Heard University of Southern Mississippi, [email protected] Jeffrey M. Lotz Gulf Coast Research Laboratory, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/parasitologyfacpubs Part of the Parasitology Commons Overstreet, Robin M.; Heard, Richard W.; and Lotz, Jeffrey M., "Microphallus fonti sp. n. (Digenea: Microphallidae) from the Red Swamp Crawfish in Southern United States" (1992). Faculty Publications from the Harold W. Manter Laboratory of Parasitology. 451. https://digitalcommons.unl.edu/parasitologyfacpubs/451 This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from the Harold W. Manter Laboratory of Parasitology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Mem./nsf. OswaldoCruz, Rio de Janeiro, Vol. 87, Suppl. 1,175-178,1992 MICROPHALLUS FONTI SP. N, (DIGENEA: MICROPHALLIDAE) FROM THE RED SWAMP CRAWFISH IN SOUTHERN UNITED STATES ROBIN M. OVERSTREET; RICHARD W. HEARD & JEFFREY M. LOTZ Gulf Coast Research Laboratory, P. O. Box 7000, Ocean Springs, Mississippi 39564, U. S. A. A new species ojdigenean, Microphallus fonti, is described from the red swamp crawfish in Louisiana, U. S. A. It has a small pharynx and a rudimentary gut like M. opacus and possibly related species from crayfishes, but it differs from them by its relatively large male copulatory papilla and a conspicuous metraterm. Key words: Microphallus font; - digenean - Procambarus clarkii - crayfish Over the past several years the authors have and sac-like to weakly bifurcate; male copula­ been aware of the occurrence of the metacer­ tory papilla well developed and bell-shaped caria of an undescribed species of microphallid with large aperture; metraternl opening later­ trematode in the digestive gland of the com­ ally into sinistral wall of genital atrium. mercially important red swamp crawfish, Procambarus c1arkii, from southern Louisiana. Description: (based on 20 whole mounted Recently, a colleague, William Font, sent us and 5 serially sectioned metacercariae): Body an excellent series of additional specimens of pyrifornl, 910 to 1,110 long by 480 to 930 in this fonn for study. The description of the new maximum width (at testicular level). Tegu­ species, which we tentatively place in the ge­ mental spines 4 to 6 long, most numerous and nus Microphallus Ward, 190 I, is the subject robust in forebody, becoming less numerous of this report. and more delicate in hindbody, usually imper­ ceptible at posterior extremity. Nervous sys­ MATERlALS AND METHODS tem conspicuous; cerebral commissure at pha­ ryngeal level with anterior and posterior lat­ Specimens were heat killed in saline under eral paired nerves; posterior lateral pair visible slight coverslip pressure, immediately fixed in into hindbody, with at least three secondary AFA, and stained in Van Cleave's hematoxy­ branches. Oral sucker subtenninal, opening lin or carmine. All figures were drawn with ventrally, 50 to 81 long by 61 to 86 wide. the aid of a camera lucida, and measurements Acetabulum 67 to 108 long by 74 to 86 wide. are given in micrometers. Sucker width ratio I: 1.06 to 1.3 8. Forebody 52 to 60% of body length. Pharynx muscular, RESULTS 28 to 42 long by 17 to 33 wide. Prepharynx Microphallus fonti sp. n. conspicuous, longer than pharyngeal length in (Figs 1-7) most specimens, 28 to 78 long. Esophagus 162 to 289 long. Intestinal caeca rudimentary, con­ Synonyms: Microphallus opacus: Soganda­ sisting of relatively few cells, sac-like to weakly res-BemaI 1965; Microphallus opacus sensu bifurcate with sac or longest portion 84 to 206 Sogandares-Bernal: Deblock & Pearson, 1969, long (Figs 2-5). Deblock, 1971, Overstreet & Perry 1972. Testes irregular in shape, symmetrical, lat­ Diagnosis: Microphallinae; muscular phar­ erally elongate; left testis 84 to 145 long by ynx relatively small; intestinal caeca reduced 123 to 279 wide; right testis 61 to 145 long by 145 to 318 wide. Seminal vesicle oval to suboval, preacetabular, 106 to 218 long by 56 to 134 at widest level, filled with spenn. Vas The study was conducted in cooperation with the U. S. Department of Agriculture, CSRS, Grant efferentia extending from anteromedial mar­ Nos. 88-38808-3319 and 92-38808-6920. gin of testes to mid acetabular level, me,rging 176 Robin M. Overstreet et al. 1 2 3 \ 4 [ 7 Microphallus jO/l/i - Fig. 1: entire specimen, ventral view, composile from two individuals, scale bar = 200 lim. Figs 2-5: variation in intestinal structure, scale bar ~ 100 lim for all four individuals. Fig. 6: male copulatory papilla extruded through genital pore, vcntral view. Fig. 7: reproductivc structures including terminal'genitalia with male papilla not extruded, scale bar = 75 lim. Mem. Inst. Oswaldo Cruz, Rio de Janeiro. Vol. 87, Suppl. I. 1992 177 to form short vas deferens; vas deferens enter­ Intensity oj injection: from a few to hun­ ing seminal vesicle at posterodorsal medial dreds per crawfish. margin. Pars prostatica well developed, 56 to 100 long by 45 to 89 wide, with conspicuous Type locality: bayous along LA Hwy 76 prostatic cells; prostatic complex surrounded near Rosedale, Louisiana, in Iberville Parish; by thin membrane; seminal vesicle and pros­ other locality: drainage canal in West Baton tatic complex together surrounded by single Rouge Parish, Louisiana, along US Hwy 190 thin membrane ("nonmuscular cirrus sac"). near junction with LA Hwy 983. Genital atrium sinistral, at acetabular level, with thick muscular wall and relatively large geni­ Holotype: USNM Helm. Coil. No. 82599; tal pore. Male copulatory papilla strongly Paratype: No. 82600, and Gulf Coast Research muscular, relatively large, larger than acetabu­ Laboratory Museum No. 1142. lum in most specimens, up to 123 long and 122 wide. Sperm duct entering papilla Etymology: the species is named in honor anterodorsally from base of organ; terminal of William F. Font for his contributions to protrusible portion distinct, appearing bell­ helminthology as well as his providing mate­ shaped when protruding from genital pore, rial of this species. variably shaped when compressed and fixed within inverted atrium. DISCUSSION Following the classification of Deblock Ovary smooth, dextral to acetabulum and (1971), we fit the species into the subgenus contiguous or immediately anterior to right Microphallus of the genus Microphallus Ward, testis, 156 to 258 long by 167 to 258 wide. 1901. In that classification, Deblock (1971) no Laur r's canal, ootype, and conspicuous longer accepted the subgenus Monocoecum Mehlis's gland in intertesticular region; Stafford, 1903, into which the species was Laurer's canal opening positioned dorsal to left placed earlier by Deblock & Pearson (1969). testis to midline; Mehlis's gland consisting of Based on the small pharynx, small rudimen­ at least one group of cells with eosinophilic tary gut, and crayfish host, M. Jonti appears cytoplasm near the ootype and another group most similar to M. opacus (Ward, 1894) and with basophilic cytoplasm surrounding and M. ovatus Osborn, 1919. The relationship be­ extending posterior to the first group. Vitellaria tween M. opacus and M. ovatus is unresolved. in two lateral groups of follicles numbering 9 Osborn (1919) separated those two on the ba­ on right and 7 or occasionally 8 on left, occu­ sis of differences in several morphological and pying a space ranging from 257 long by 128 biological features, which according to later wide to 441 long by 246 wide, extending from workers were either not consistent or not ac­ near posterior end of worm to or beyond tes­ curate. Van Cleave & Mueller (1934) ques­ tes; follicles usually irregular in shape, 50 to tioned whether M. ovatus was a variety of M. 179 long by 56 to 112 wide. Uterus largely opactls, and Strandine (1943) considered it as confined to hindbody in intertesticular region. such. That problem is not of importance for Metraterm thick walled, often convoluted, 80 this paper because M. jOnti clearly differs from to 120 long, associated with small glandular them both. Actually, a complex of species cells; terminal portion dilated, opening later­ related to M. opacus may exist, but critical ally into sinistral wall of genital atrium. Eggs evaluation including life history studies will undeveloped. be necessary to ascertain this. Microphallus Jonti can be most readily differentiated from Excretory vesicle "Y" shaped with short M. opactls by its relatively large male copula­ stem and without lateral bulges, well epithe­ tory papilla and a conspicuous metraterm. Iiated. Excretory pore subterminal, occasion­ ally in fixed specimens occurring on dorsal or The poorly developed gut appears to be a ventral surface. 110moplasy illustrating parallel development. It is at least partly dependent on the nutritional Intermediate and type host: Procambarus needs of the species and probably developed clarkii (Girard, 1852) (red swamp crawfish, from paired, elongated, ancestral intestinal Cambaridae). caeca. In addition to occurring