Temnocephala iheringi Haswell, 1893

Seixas, Samantha A., Amato, Suzana B. & Amato, José F. R., 2020, Temnocephalan epibionts (Platyhelminthes, Temnocephalida) on mollusks from Pantanal wetland, Brazil, Zootaxa 4858 (3), pp. 341-357 : 343

Temnocephala iheringi Haswell, 1893

( Figs 1 A–E, 2A–B, 2D–G, 3A–B, 4A–C, 5A–L, 6A–D, 7A–D)

Study based on 54 collected specimens: 42 specimens mounted in toto; 4 specimens mounted on stubs for SEM; 12 extracted cirri mounted in Faure; and 13 specimens measured.

Table 1 presents all the morphometric data of the specimens of T. iheringi from M. planogyra (present work), P. maculata (present work), and the data provided by Seixas et al. (2010a) from P. canaliculata .

Taxonomic summary. Type host. Ampullaria (= Pomacea ) sp. ( Haswell 1893); Pomacea canaliculata (Lamarck, 1822) ( Gastropoda, Caenogastropoda, Ampullariidae ) ( Seixas et al. 2010a).

Type locality. Brazil ( Haswell 1893); probably Camaquã, RS, Brazil ( Seixas et al. 2010a).

Other hosts and localities. Pomacea lineata (Spix in Wagner, 1827) , Salobra and Guaicurús, MS, Brazil ( Pereira & Cuocolo 1941); Asolene platae (Maton, 1809) , Río San Javier, Santa Fe, Argentina ( Hyman 1955); Pomacea sp., Soriano and San José, Uruguay ( Dioni 1967); Pomacea canaliculata (Lamarck, 1822) , Parana medio, Argentina ( Di Persia & Radici de Cura 1973); ruta Interbalnearia (km 21), Canelones, Uruguay (Flecher & Ponce de León 1983); Avenida Italia (km 21,5), Canelones, Uruguay ( González et al. 1987); Laguna Don Felipe, Santa Fe and Punta Lara, Canteras de Los Talas, Arroyo Doña Flora, Punta Indio, Buenos Aires, Argentina ( Damborenea 1992); Playa Bagliardi, Berisso, Buenos Aires, Argentina ( Damborenea 1996); Arroyo Zapata, Magdalena, Buenos Aires, Argentina ( Damborenea & Cannon 2001); Ilha da Pintada and Sava Clube, Lago Guaíba, Porto Alegre, RS, Brazil; Sossego Farm, Santa Vitória do Palmar, RS, Brazil; Ponta do Ceroula, Barra do Ribeiro, RS, Brazil; Praia Florida, Lago Guaíba, Guaíba, RS, Brazil; Arrozeira, Eldorado do Sul, RS, Brazil; Barra do Ouro, Maquiné, RS, Brazil ( Seixas et al. 2010a); Pomella megastoma (Sowerby, 1825) , Río de La Plata, Buenos Aires, Argentina ( Damborenea et al. 1997, Damborenea et al. 2006, Vega et al. 2006); Marisa planogyra Pilsbry, 1933 and Pomacea maculata Perry, 1810 , ( Gastropoda, Caenogastropoda, Ampullariidae ), Ypiranga Farm, Poconé, Mato Grosso, Brazil (present work).

Site of infestation. Adults and juveniles in mantle cavity, eggs in umbilicus, suture, and spire, sometimes in larger numbers in the body whorl of the host shell; never present on operculum in M. planogyra , and present on operculum in P. maculata .

Other helminth specimens examined. Temnocephala iheringi from P. canaliculata— specimens deposited in the ‘Coleção Helmintológica do Laboratório de Helmintologia da UFRGS’, Porto Alegre, Rio Grande do Sul, Brazil, and ‘Colección de Invertebrados, División Zoologia Invertebrados, Museo de La Plata ( MLP)’, La Plata, Argentina: MLP-He 3118 (Arroyo Miguelin, Punta Lara); MLP-He 3119 and 3121 (Canteras de Berisso, Los Talas, Berisso); MLP-He 3120 (Arroyo Doña Flora, Ensenada, Buenos Aires, Argentina).

Helminth specimens deposited. ‘Colección de Invertebrados, División Zoologia Invertebrados, Museo de La Plata ( MLP)’, La Plata, Argentina: Temnocephala iheringi from M. planogyra : MLP-He 7696 (two specimens in toto and one cirrus) and T. iheringi from P. maculata : MLP-He 7697 (two specimens in toto and two cirri).

Remarks. Infrapopulations of T. iheringi epibionts on M. planogyra and P. maculata showed some intraspecific variations. The adhesive disk (length and width) and the width of the pharynx were significantly different between the two infrapopulations. The adhesive disk of specimens of T. iheringi from M. planogyra was smaller than in the specimens from P. maculata (p = 0.001), and the pharynx of specimens of T. iheringi from P. maculata was less wide than in the specimens from M. planogyra (p = 0.043). The male reproductive system presented important distinctions between specimens from both hosts. The length of the shaft and the introvert were significantly different, specimens of T. iheringi from M. planogyra had a smaller shaft (p = 0.047) but a larger introvert (p = 0.039). The introvert of the specimens from P. maculata had a slight curvature (approximately 20 o) in just one of the sides at the proximal limit of the introvert ( Figs 5G and 6D ). The spines of the introvert also differed significantly between both infrapopulations. The spines of specimens from M. planogyra were shorter and with a more robust base ( Fig. 5E ) than in the specimens from P. maculata ( Fig. 5K ) (p = 0.007). The female reproductive system was very similar among specimens from both hosts, having no significant variations in any measurement. Only T. iheringi ’s eggs from M. planogyra were recorded showing one side of the ring of opercular plates around the apical pole of the egg ( Fig. 1D ), and a subapical filament ( Fig. 1E ).The eggs were deposited in umbilicus, suture, and spire, sometimes in larger numbers in the body whorl of the host shell ( Fig. 1A and B ); they were never present on the operculum in M. planogyra , but were on the operculum in P. maculata .

Figures

FIGURE 1. Hosts and eggs of Temnocephala iheringi. A and B. Marisa planogyra. (A) Ventral view of the shell showing areas of egg of T. iheringi deposition (arrows). Scale bar = 1 cm. (B) Higher magnification. Scale bar = 0.5 cm. C, D and E. Eggs of T. iheringi from M. planogyra. Scale bars = 100 μm. (C) Pedunculated unhatched egg. (D) Sessile unhatched egg, showing a series of opercular plates (head arrows). (E) Sessile unhatched egg, showing subapical filament (arrow). (F) Pomacea maculata, ventral view of the shell. Scale bar = 1 cm. G and H. Pomacea scalaris. Scale bars = 1 cm. (G) Dorsal view of the shell. (H) Ventral view of the shell.

FIGURE 5. Photomicrographs of cirri, seen with Nomarski’s DIC microscopy. A–F. Temnocephala iheringi from Marisa planogyra. (A) Entire cirrus, showing the thickening ring on the base of the swelling (white head arrows), the proximal limit of introvert (arrow), and the shaft rim (black head arrows) typical of adult worms. Scale bar = 25 μm. (B–F) Introvert seen in different focusing planes, from the top of the internal surface to mid-section, showing the thickening ring on the base of the swelling (head arrow). Scale bars = 10 μm. G–L. Temnocephala iheringi from Pomacea maculata. (G) Entire cirrus, showing the thickening ring on the base of the swelling (white head arrows), the proximal limit of introvert (arrow), and the shaft rim (black head arrow). Scale bar = 25 μm. (H–L) Introvert seen in different focusing planes, from the top of the internal surface to mid-section, showing the thickening ring on the base of the swelling (head arrow). Scale bars = 20 μm. M–Q. Temnocephala amatoi sp. nov. (M) Entire cirrus, showing the proximal limit of introvert (arrow), and the shaft rim (head arrows). Scale bar = 5 μm. (N–Q) Introvert seen in different focusing planes, from the top of the internal surface to mid-section, showing the proximal limit of introvert (arrows) and the longer (black head arrow) and smaller (white head arrow) spines on the introvert. Scale bars = 10 μm.

FIGURE 6. Diagrams of adult specimens. A and B. Temnocephala iheringi from Marisa planogyra. (A) Incomplete diagram. Scale bar = 250 μm. (B) Diagram of cirrus. Scale bar = 25 μm. C and D. Temnocephala iheringi from Pomacea maculata. (C) Incomplete diagram. Scale bar = 250 μm. (D) Diagram of cirrus. Scale bar = 10 μm. E and F. Temnocephala amatoi sp. nov. (E) Incomplete diagram. Scale bar = 250 μm. (F) Diagram of cirrus. Scale bar = 20 μm. (adhesive disk (ad), anterior testes (at), brain transverse band (b), excretory vesicle (ev), Haswell glands (hg), intestine (i), mouth (m), pharynx (ph), posterior testis (pt), proximal limit of the introvert (arrow), thickening on the base of the introvert (head arrow), vitelline glands (vg), and tentacles (t)).