Monogenea) of Redbreast Sunfish, Bluegill, and Their Hybrids from Lake Norman, North Carolina: Remarks on Monogeneans As Indicators of Parent Species of Hybrids

108 PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY

against experimental alveolar hydatid disease. Helminths of the coyote (Canis latrans Say) in Journal of Helminthology 59:29-38. Montana. Journal of Wildlife Diseases 19:54-55. Ohbayashi, M., R. L. Rausch, and F. H. Fay. 1971. -, and D. E. Worley. 1976. The occurrence of On the ecology and distribution of Echinococcus. Echinococcus rnultilocularis Leuckart, 1863 (Ces- II. Comparative studies on the development of toda: Taeniidae) in the red fox, Vulpes vulpes, in larval Echinococcus rnultilocularis in the inter- southwestern Montana. Proceedings of the Mon- mediate host. Japanese Journal of Veterinary Re- tana Academy of Science 36:145-149. search 19(Suppl. 3): 1-53. Shiryaev, V. V. 1983. [Dynamics of muskrat infec- Rausch, R., and S. H. Richards. 1971. Observations tion by helminths in the Balkash Territory (USSR) on parasite-host relationships of Echinococcus related to irrigation.] Byulleten' Moskovskogo Ob- rnultilocularis Leuckart, 1863 in North Dakota. shchestva Ispytatelei Prirody, Otdel Biologiches- Canadian Journal of Zoology 49:1317-1330. kii 88:62-67. (Helminthological Abstracts 1984, Seesee, F. M., M. C. Sterner, and D. E. Worley. 1983. Part A, Number 4.)

Proc. Helminthol. Soc. Wash. 55(1), 1988, pp. 108-110

Research Note Ancyrocephalids (Monogenea) of Redbreast Sunfish, Bluegill, and Their Hybrids from Lake Norman, North Carolina: Remarks on Monogeneans as Indicators of Parent Species of Hybrids

DONALD G. CLOUTMAN Duke Power Company, Applied Science Center, Route 4, Box 531, Huntersville, North Carolina 28078

ABSTRACT: Five ancyrocephalid species were found species of hybrids that are difficult, if not im- on redbreast sunfish, Lepomis auritus, 1 on bluegill, L. possible, to identify through morphometric char- macrochirus, and 8 on redbreast sunfish x bluegill hy- acters. brids from Lake Norman, North Carolina. All 8 species infesting the hybrids were present on one or both of Ancyrocephalid monogeneans have been re- the parent species. The hybrids inherited the ability to ported from all 11 species of the sunfish genus harbor monoxenous parasites from their parent species. Lepomis (see Hoffman, 1967; Beverley-Burton, Investigators may be able to use monogeneans, espe- 1984). However, only 1 species of ancyroceph- cially monoxenous species, to identify parent species of hybrids, which are often difficult to identify. Uro- alid from 2 Lepomis hybrid combinations has cleidus tuberculatus Allison and Rogers, 1970, is trans- been reported (Mizelle, 1936), although Lepomis ferred to Onchocleidus as Onchocleidus tuberculatus hybrids are common in nature (Childers, 1967). (Allison and Rogers, 1970) comb. n. Mizelle (1936) listed Onchocleidus ferox (Muel- KEY WORDS: Monogenea, Ancyrocephalidae, Ac- ler, 1934) as O. mucronatus Mizelle, 1936, from tinocleidus bennetti, Actinocleidus fergusoni, Anchora- discus anchoradiscus, Cleidodiscus robustus, Haplo- bluegill (L. macrochirus Rafinesque) x pump- cleidus dispar, Onchocleidus ferox, Onchocleidus kinseed (L. gibbosus (Linnaeus)), orangespotted tuberculatus comb, n., Pterocleidus acer, bluegill, red- sunfish (L. humilis (Girard)) x pumpkinseed, and breast sunfish, hybrids, Lepomis auritus, Lepomis mac- all 3 parent species. This paper reports on the rochirus. species and abundance of ancyrocephalids par- Nybelin (1937) reported that only those dac- asitizing redbreast sunfish (L. auritus (Lin- tylogyrid monogeneans parasitizing the parent naeus)) x bluegill and their parent species from host species were found on 3 cyprinid hybrid Lake Norman, North Carolina, and further in- combinations. These data indicate that mono- vestigates the use of monogeneans to identify geneans may be useful in determining parent parent species of hybrid fishes.

Table 1. Relative density (total number of parasites/total number of hosts), range, and prevalence (% infestation) of ancyrocephalids infesting redbreast sunfish, bluegill, and their hybrids from Lake Norman, North Carolina.

Redbreast sunfish Bluegill Hybrids Rela- Rela- Rela- tive Prev- tive Prev- tive Prev- Parasite density Range alence density Range alence density Range alence

Actinocleidus bennetti Allison and Rogers, 1970 3.1 0-8 88.9 0.0 0 0.0 1.0 0-5 55.6 Actinocleidus fergusoni Mizelle, 1938 0.0 0 0.0 16.2 1-36 100.0 1.3 0-8 44.4 Actinocleidus sp. 0.1 0-1 11.1 0.0 0 0.0 0.2 0-1 22.2 Anchoradiscus anchoradiscus Mizelle, 1941 0.0 0 0.0 0.3 0-1 33.3 0.0 0 0.0 Cleidodiscus robustus Mueller, 1934 0.0 0 0.0 0.3 0-1 33.3 0.0 0 0.0 Haplodeidus dispar (Mueller, 1936) 6.3 3-20 100.0 7.2 0-21 88.9 16.8 2-37 100.0 Onchocleidus ferox (Mueller, 1934) 0.0 0 0.0 7.3 0-19 88.9 2.9 0-6 88.9 Onchocleidus tuberculatus (Allison and Rogers, 1970) comb. n. 4.0 0-10 77.8 0.0 0 0.0 1.4 0-6 44.4 Onchocleidus sp. 0.0 0 0.0 0.2 0-2 11.1 0.2 0-1 22.2 Pterocleidus acer (Mueller, 1936) 0.1 0-1 11.1 2.0 0-4 77.8 2.0 0-5 77.8 Total 13.6 3-25 100.0 33.5 2-6 1 100.0 25.8 4-57 100.0

Nine specimens each of redbreast sunnsh, (Table 1). Five ancyrocephalid species were found bluegill, and redbreast sunnsh x bluegill hybrids on redbreast sunfish, 7 on bluegill, and 8 on the ranging from 117 to 137 mm (total length) were hybrids. Redbreast sunfish harbored 3 species caught by angling in a single cove on Lake Nor- not found on bluegill, whereas bluegill harbored man, Lincoln County, North Carolina, during 5 species not found on redbreast sunfish. Hap- 12-14 April 1985. Although some Lepomis hy- lodeidus dispar (Mueller, 1936) and Pterocleidus brid combinations are difficult or seemingly im- acer (Mueller, 1936) were the only ancyroceph- possible to identify, these redbreast sunfish x alids found on both redbreast sunfish and blue- bluegill hybrids were easily identified because of gill. All 8 species infesting the hybrids were pres- their intermediate color patterns and morpho- ent on one or both of the parent species. The metric characters. The gills were excised and fro- lack of Anchoradiscus anchoradiscus Mizelle, zen immediately after the fish were caught. After 1941, and Cleidodiscus robustus Mueller, 1934, being frozen overnight, the gills were preserved on the hybrids was probably due to the small in 10% formalin. The ancyrocephalids were sample size of hosts and rarity of the parasites picked from the gills under a dissecting micro- (lacking on redbreast sunfish and 0.3 parasites scope, mounted in glycerin jelly, and identified per host on bluegill) rather than inability of the under a phase contrast microscope. hybrids to harbor these species. The data show Ten species of ancyrocephalids representing 6 that the hybrids inherited the ability to harbor genera (sensu Beverley-Burton, 1984,1986) were monoxenous parasites from their parent species. found during this study (Table 1). Urocleidus tu- For example, Actinocleidus bennetti Allison and berculatus Allison and Rogers, 1970, is trans- Rogers, 1970, Actinocleidus sp., and O. tuber- ferred to Onchocleidus as Onchocleidus tuberculatus, known only from redbreast sunfish, and culatus (Allison and Rogers, 1970) comb, n., Onchocleidus sp., known only from bluegill, were based on the presence of a type 2 penis, accessory found also on the hybrids. It is also important piece with proximal aperture through which dis- to note that species of ancyrocephalids found tal tip of penis protrudes, 2 pairs of approxi- only on other species of Lepomis inhabiting Lake mately equal-sized hamuli lacking a projection Norman (Actinocleidus oculatus (Mueller, 1934), on inner curve of blades, transverse bars not ar- Actinocleidus recurvatus Mizelle and Donahue, ticulating with each other, marginal hooks dis- 1944, and O. similus Mueller, 1936, on pump- similar in shape and size, and other characters kinseed; Actinocleidus flagellatus Mizelle and of the genus Onchocleidus Mueller, 1936 (see Seamster, 1939, Clavunculus okeechobeensis Beverley-Burton, 1984). (Mizelle and Seamster, 1939), and O. chaeno- All sunfish were infested with ancyrocephalids bryttus (Mizelle and Seamster, 1939) on war-

Copyright © 2011, The Helminthological Society of Washington 110 mouth, L. gulosus (Cuvier); Actinocleidus bifidus cially monoxenous species, may be used widely Mizelle and Cronin, 1943, Clavunculus bifur- to identify or verify identifications of parent catus (Mizelle, 1941), and O. variabilis (Mizelle species of hybrid fishes. A limitation, as was the and Cronin, 1943) on redear sunfish, L. micro- case here, is that an individual specimen of a lophus (Gunther)) were not found on the hybrids hybrid may harbor species of parasites from only (unpubl. data). 1 parent species, or no parasites. Therefore, a The 2 ancyrocephalids that occurred on both sample of several individuals may be necessary parent species had either equal (P. acer) or great- to determine parent species. er (H. dispar) relative densities on the hybrids (Table 1). However, the ability of the hybrids to harbor an ancyrocephalid found on only one of Literature Cited the parent species appears to be moderated. Rel- Beverley-Burton, M. 1984. Monogenea and Turbel- ative densities of A. bennetti, A. fergusoni Miz- laria. Pages 5-209 in L. Margolis and Z. Kabata, elle, 1938, O. ferox, and O. tuberculatus on the eds. Guide to the Parasites of Fishes of Canada. Part 1. Canadian Special Publication of Fisheries hybrids were less than those on the infested par- and Aquatic Sciences 74. Ottawa. ent host species. The 2 exceptions to this trend . 1986. The taxonomic status of Actinocleidus were Actinocleidus sp. and Onchocleidus sp., Mueller, 1937; Anchoradiscus Mizelle, 1941; Cla- which were rare on the parent host species and vunculus Mizelle et al., 1956; Anchoradiscoides Rogers, 1967; Syndeithrium Price, 1967 and Crin- hybrids. If 1 or 2 more individuals of these par- icleidus n. gen.: North American ancyrocephalids asites had occurred in the parent host samples, (Monogenea) with articulating haptoral bars. Jour- these parasites also would have displayed smaller nal of Parasitology 72:22-44. relative densities on the hybrids than on the par- Childers, W. F. 1967. Hybridization of four species ent species. of sunfishes (Centrarchidae). Illinois Natural His- tory Survey Bulletin 29:159-214. This sample of redbreast sunfish x bluegill Hoffman, G. L. 1967. Parasites of North American hybrids from Lake Norman could have been Freshwater Fishes. University of California Press, identified by analysis of ancyrocephalid parasites Berkeley, California. 486 pp. because the specimens harbored only those Mizelle, J. D. 1936. New species of trematodes from the gills of Illinois fishes. American Midland Nat- species of ancyrocephalids found on the parent uralist 17:785-806. species. These data, in corroboration with Ny- Nybelin, O. 1937. Kleine Beitrage zur Kenntnis der belin (1937), suggest that monogeneans, espe- Dactylogyren. Arkiv foer Zoologi 16:1-2.

Obituary Notices NORMAN A. MEINKOTH Born: 29 January 1913 Elected Member: 14 January 1948 Deceased: Spring 1987 18th Vice President of the Society in 1952

LLOYD ANCIL SPINDLER Born: 1900 Deceased: 16 November 1987 Elected Member: 10 November 1927 Offices Held: 9th Recording Secretary, 1933 18th President, 1935