Journal of Helminthology (1977) 51, 205—208
Mesocoelium malayanum sp.n. (Digenea: Brachycoeliidae) in a frog, Rana macrodon Dumeril and Bibron 1941, from Malaysia JAMES R. PALMffiRI and JOHN T. SULLIVAN University of California I.C.M.R., Institute for Medical Research, Kuala Lumpur, Malaysia
ABSTRACT Mesocoelium malayanum sp.n. is described from the frog Rana macrodon, in Malaysia. Elongate body, broader anteriorly, measuring 1 -900 (1-679-2070) mm long by 0-404 (0-380-0-437) wide, tegument aspinose oral sucker 0-212 (0-200-0-228) by 0-202 (0191-0-205), acetabulum 0141 (0132-0150) by 0-139 (0-1230-146), prepharynx present, oesophagus 0-115 (0-096-0-137), caeca reaching posterior J of body, anterior testis 0097 (0087-0110) by 0091 (0087-0100) dorsal to acetabulum, posterior testis 0094 (0-087-0-101 by 0092 (0091-0100), cirrus pouch 0121 (0111-0130) by 0047 (0-041-0055), genital pore at left of midline of oesophagus just anterior to intestinal bifurcation, ovary 0110 (0-091-0-127) by 0089 (0-0850-096) on left of body and posterior to acetabulum, vitelline glands with single follicles extending from intestinal bifurcation to ends of caeca, excretory vesicle I-shaped and eggs 0-040 (0-037-0-046) by 0023 (0022-0-024). Although morphologically related to M. maroccanum and M. meggitti, M. malayanum is considered to be a new species.
Examination of frogs {Rana macrodon) collected from the Kelang River drainage, Kelang Gates, Malaysia revealed a new species of Mesocoelium. Although Cheng (1960) listed 28 valid species, and Yamaguti (1971) listed 27 species, yet much discrepancy exists. Furthermore, much synonymy of the reported species of Mesocoelium is evident in the literature (Cheng, 1960; Freitas, 1963; Fischthal and Kuntz, 1965; and Yamaguti, 1971), and is undoubtedly due to morphological overlap of specimens recovered from various hosts throughout the world.
MATERIALS AND METHODS From March through August 1976, amphibians were collected by dipnet and trap from the Kelang River drainage 10 miles northeast of Kuala Lumpur, Malaysia. Upon return to our laboratory, hosts were identified, killed and immediately examined for parasites. Trematodes were removed, washed in saline solution, fixed in hot AFA, stained in Mayer's paracarmine and counterstained in fast green, dehydrated, cleared in methyl salicylate and mounted in Permount. A type series of 8 adult specimens from a single host was examined with a Leitz Ortholux Microscope. Eggs were measured through the body wall of stained specimens. All measurements are reported as averages with ranges in parentheses, and are in millimeters unless otherwise indicated. 205
J. A. PALMIERI and J. T. SULLIVAN
Mesocoelium malayanum sp.n. (Fig. 1) Description (based on 8 specimens): Body elongate, broader anteriorly than posteriorly, 1-900 (1-679-2-070) long by 0-404 (0-380-0-437) wide; tegument aspinose in anterior and posterior body; anterior sucker 0-212 (0-200-0-228) by 0-202 (0-191-0-205); ventral sucker 0-141 (0-132-0-150) by 0-139 (0-123-0-146); prepharynx 0-010 (0O09-O-011); pharynx 0-072 (0-068-0-074) by 0085 (0-073-0-091); oesophagus 0-115 (0096-0-137); intestinal caeca reaching posterior third of body; testes round to subround; anterior testis 0-097 (0-087-0-110) by 0-091 (0-087-0-100) and posterior testis 0094 (0-087-0-101) by 0-092 (0091-0-100); anterior testis is superimposed by acetabulum, and diagonally opposed to posterior testis, which is lateral to posterior third of acetabulum; cirrus pouch 0-121 (0-111-0-130) by 0-047 (0-041-0-055); genital pore at left of midline of oesophagus and at or just anterior to intestinal bifurcation; ovary subround 0110 (0-091-0-127) by 0-089 (0-085-0-096), on left of body and posterior to acetabulum and anterior testis; vitelline glands singularly follicular, lateral from level of intestinal bifurcation to ends of caeca; excretory vesicle I-shaped extending just below caeca; eggs 0-040 (0-037-0-046) by 0-023 (0-022-0-024). Host: Rana macrodon Site: Mid-intestine Locality: Kelang River, Kelang Gates, Selangor State, Malaysia Holotype: USNM Helm. Col. No. 74026 Paratype: USNM Helm. Col. No. 74027 DISCUSSION Little is known about the life cycle of most species of Mesocoelium. All previous taxonomic considerations of this genus have been based upon adult morphology thereby accounting for much of the existing synonomy. Mesocoelium malayanum has intestinal caeca which extend beyond the midpoint of the body. The genital pore is situated lateral to the midline and just anterior to the bifurcaiion of the caeca and to the left of the oesophagus. The only other two reported species which are morphologically similar are M. maroccanum Dollfus, 1951 and M. meggitti Bhalerao, 1927, the latter being placed in synonymy with M. sociale (Liihe 1910) Odhner 1910 by Fischthal and Kuntz (1965). Freitas (1967) placed M. sociale in synonymy with M. monas (Rud, 1819). Although many morphological characters of M. malayanum overlap with those of M. maroccanum and M. meggitti, many characters are quite distinct (Fig. 2). For example, both M. maroccanum and M. meggitti differ from M. malayanum in that they possess a spinose tegument and M. malayanum an aspinose tegument. M. malayanum differs from M. maroccanum in the following characters: cirrus pouch size relative to acetabulum, oesophagus length, testis shape, ovary size, position of anterior testis relative to acetabulum, and vitelline gland extent. M. malayanum differs from M. meggitti in the following characters: cirrus pouch length, oesophagus length, testis size relative to acetabulum, ovary size, presence of prepharynx and vitelline gland extent. Based on morphological distinctions Mesocoelium malayanum is considered to be a new species. 206
Mesocoelium malayanum sp.n. in a Malayan frog
FIG. 1. Mesocoelium malayanum. Ventral view of holotype. Abbreviations: Acetabulum (A), Anterior testis (AT), Excretory bladder (B), Body (BO), Cirrus sac (Q, Caeca (CE), Egg (E), Oesophagus (ES), Genital pore (G), Length (L), Oral sucker (O), Ovary (OV), Pharynx (P), Prepharynx (PP), Posterior testis (PT), Seminal receptical (S), Testis (T), Uterus (U), Vitellaria (V), Width (W). 207
J. A. PALMIERI and J. T. SULLIVAN
O.3O
3.O
O.25
2.5
O.2O
2.0
0.15
1,5
O.1O
1.0
O.O5
O.5
o«
o(w) A(g
P(W)ES(L)OV(L)OV(W)EW
E(W)
BO(L) BCKVV)
FIG. 2. Comparison of measurements (average and range) of morphological characters of Mesocoelium malayanum with M. maroccanum and M. meggitti. 1 = M. malayanum, 2 = M. maroccanum, 3 = M. meggitti. All measurements in millimeters.
ACKNOWLEDGEMENTS This work was supported in part by grant AI 10051 (UC ICMR) to the Department of International Health, School of Medicine, University of California, San Francisco, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service.
REFERENCES CHENG, T. (1960) Studies on the trematode family Brachycoeliidae. IV. A revision of the genus Mesocoelium Odhner, 1911, and the status of Pintnaria Poche, 1907. American Midland Naturalist, 439-469. FISCHTHAL, J. and R. KUNTZ. (1965) Digenetic trematodes of amphibians and reptiles from North Borneo (Malaysia). Proceedings of the Helminthological Society of Washington, 32, 124-136. FREITAS, J. F. T. de. (1963) Revisao Da Familia Mesocoeliidae Dollfus, 1933 (Trematoda). Memorias Do Instituto Oswaldo Cruz, 61, 177-311. FREITAS, J. F. T. de. (1967) Notas sobre trematodos Mesocoeliideos. Boletim Do Museu De Biologia Prof. Mello-Leitao, Zool. No. 30, 11 pp. YAMAGUTI, S. (1971) Synopsis of Digenetic Trematodes of Vertebrates. Vol. I. 1074 pp. Keigaku Publishing Co. Tokyo. Received 16 March, 1977.
208
Mesocoelium malayanum sp.n. (Digenea: Brachycoeliidae) in a frog, Rana macrodon Dumeril and Bibron 1941, from Malaysia JAMES R. PALMffiRI and JOHN T. SULLIVAN University of California I.C.M.R., Institute for Medical Research, Kuala Lumpur, Malaysia
ABSTRACT Mesocoelium malayanum sp.n. is described from the frog Rana macrodon, in Malaysia. Elongate body, broader anteriorly, measuring 1 -900 (1-679-2070) mm long by 0-404 (0-380-0-437) wide, tegument aspinose oral sucker 0-212 (0-200-0-228) by 0-202 (0191-0-205), acetabulum 0141 (0132-0150) by 0-139 (0-1230-146), prepharynx present, oesophagus 0-115 (0-096-0-137), caeca reaching posterior J of body, anterior testis 0097 (0087-0110) by 0091 (0087-0100) dorsal to acetabulum, posterior testis 0094 (0-087-0-101 by 0092 (0091-0100), cirrus pouch 0121 (0111-0130) by 0047 (0-041-0055), genital pore at left of midline of oesophagus just anterior to intestinal bifurcation, ovary 0110 (0-091-0-127) by 0089 (0-0850-096) on left of body and posterior to acetabulum, vitelline glands with single follicles extending from intestinal bifurcation to ends of caeca, excretory vesicle I-shaped and eggs 0-040 (0-037-0-046) by 0023 (0022-0-024). Although morphologically related to M. maroccanum and M. meggitti, M. malayanum is considered to be a new species.
Examination of frogs {Rana macrodon) collected from the Kelang River drainage, Kelang Gates, Malaysia revealed a new species of Mesocoelium. Although Cheng (1960) listed 28 valid species, and Yamaguti (1971) listed 27 species, yet much discrepancy exists. Furthermore, much synonymy of the reported species of Mesocoelium is evident in the literature (Cheng, 1960; Freitas, 1963; Fischthal and Kuntz, 1965; and Yamaguti, 1971), and is undoubtedly due to morphological overlap of specimens recovered from various hosts throughout the world.
MATERIALS AND METHODS From March through August 1976, amphibians were collected by dipnet and trap from the Kelang River drainage 10 miles northeast of Kuala Lumpur, Malaysia. Upon return to our laboratory, hosts were identified, killed and immediately examined for parasites. Trematodes were removed, washed in saline solution, fixed in hot AFA, stained in Mayer's paracarmine and counterstained in fast green, dehydrated, cleared in methyl salicylate and mounted in Permount. A type series of 8 adult specimens from a single host was examined with a Leitz Ortholux Microscope. Eggs were measured through the body wall of stained specimens. All measurements are reported as averages with ranges in parentheses, and are in millimeters unless otherwise indicated. 205
J. A. PALMIERI and J. T. SULLIVAN
Mesocoelium malayanum sp.n. (Fig. 1) Description (based on 8 specimens): Body elongate, broader anteriorly than posteriorly, 1-900 (1-679-2-070) long by 0-404 (0-380-0-437) wide; tegument aspinose in anterior and posterior body; anterior sucker 0-212 (0-200-0-228) by 0-202 (0-191-0-205); ventral sucker 0-141 (0-132-0-150) by 0-139 (0-123-0-146); prepharynx 0-010 (0O09-O-011); pharynx 0-072 (0-068-0-074) by 0085 (0-073-0-091); oesophagus 0-115 (0096-0-137); intestinal caeca reaching posterior third of body; testes round to subround; anterior testis 0-097 (0-087-0-110) by 0-091 (0-087-0-100) and posterior testis 0094 (0-087-0-101) by 0-092 (0091-0-100); anterior testis is superimposed by acetabulum, and diagonally opposed to posterior testis, which is lateral to posterior third of acetabulum; cirrus pouch 0-121 (0-111-0-130) by 0-047 (0-041-0-055); genital pore at left of midline of oesophagus and at or just anterior to intestinal bifurcation; ovary subround 0110 (0-091-0-127) by 0-089 (0-085-0-096), on left of body and posterior to acetabulum and anterior testis; vitelline glands singularly follicular, lateral from level of intestinal bifurcation to ends of caeca; excretory vesicle I-shaped extending just below caeca; eggs 0-040 (0-037-0-046) by 0-023 (0-022-0-024). Host: Rana macrodon Site: Mid-intestine Locality: Kelang River, Kelang Gates, Selangor State, Malaysia Holotype: USNM Helm. Col. No. 74026 Paratype: USNM Helm. Col. No. 74027 DISCUSSION Little is known about the life cycle of most species of Mesocoelium. All previous taxonomic considerations of this genus have been based upon adult morphology thereby accounting for much of the existing synonomy. Mesocoelium malayanum has intestinal caeca which extend beyond the midpoint of the body. The genital pore is situated lateral to the midline and just anterior to the bifurcaiion of the caeca and to the left of the oesophagus. The only other two reported species which are morphologically similar are M. maroccanum Dollfus, 1951 and M. meggitti Bhalerao, 1927, the latter being placed in synonymy with M. sociale (Liihe 1910) Odhner 1910 by Fischthal and Kuntz (1965). Freitas (1967) placed M. sociale in synonymy with M. monas (Rud, 1819). Although many morphological characters of M. malayanum overlap with those of M. maroccanum and M. meggitti, many characters are quite distinct (Fig. 2). For example, both M. maroccanum and M. meggitti differ from M. malayanum in that they possess a spinose tegument and M. malayanum an aspinose tegument. M. malayanum differs from M. maroccanum in the following characters: cirrus pouch size relative to acetabulum, oesophagus length, testis shape, ovary size, position of anterior testis relative to acetabulum, and vitelline gland extent. M. malayanum differs from M. meggitti in the following characters: cirrus pouch length, oesophagus length, testis size relative to acetabulum, ovary size, presence of prepharynx and vitelline gland extent. Based on morphological distinctions Mesocoelium malayanum is considered to be a new species. 206
Mesocoelium malayanum sp.n. in a Malayan frog
FIG. 1. Mesocoelium malayanum. Ventral view of holotype. Abbreviations: Acetabulum (A), Anterior testis (AT), Excretory bladder (B), Body (BO), Cirrus sac (Q, Caeca (CE), Egg (E), Oesophagus (ES), Genital pore (G), Length (L), Oral sucker (O), Ovary (OV), Pharynx (P), Prepharynx (PP), Posterior testis (PT), Seminal receptical (S), Testis (T), Uterus (U), Vitellaria (V), Width (W). 207
J. A. PALMIERI and J. T. SULLIVAN
O.3O
3.O
O.25
2.5
O.2O
2.0
0.15
1,5
O.1O
1.0
O.O5
O.5
o«
o(w) A(g
P(W)ES(L)OV(L)OV(W)EW
E(W)
BO(L) BCKVV)
FIG. 2. Comparison of measurements (average and range) of morphological characters of Mesocoelium malayanum with M. maroccanum and M. meggitti. 1 = M. malayanum, 2 = M. maroccanum, 3 = M. meggitti. All measurements in millimeters.
ACKNOWLEDGEMENTS This work was supported in part by grant AI 10051 (UC ICMR) to the Department of International Health, School of Medicine, University of California, San Francisco, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service.
REFERENCES CHENG, T. (1960) Studies on the trematode family Brachycoeliidae. IV. A revision of the genus Mesocoelium Odhner, 1911, and the status of Pintnaria Poche, 1907. American Midland Naturalist, 439-469. FISCHTHAL, J. and R. KUNTZ. (1965) Digenetic trematodes of amphibians and reptiles from North Borneo (Malaysia). Proceedings of the Helminthological Society of Washington, 32, 124-136. FREITAS, J. F. T. de. (1963) Revisao Da Familia Mesocoeliidae Dollfus, 1933 (Trematoda). Memorias Do Instituto Oswaldo Cruz, 61, 177-311. FREITAS, J. F. T. de. (1967) Notas sobre trematodos Mesocoeliideos. Boletim Do Museu De Biologia Prof. Mello-Leitao, Zool. No. 30, 11 pp. YAMAGUTI, S. (1971) Synopsis of Digenetic Trematodes of Vertebrates. Vol. I. 1074 pp. Keigaku Publishing Co. Tokyo. Received 16 March, 1977.
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