Temnocephala pignalberiae Dioni, 1967

Amato, José F. R., Amato, Suzana B., Seixas, Samantha A., Fonseca, Mariluce & Ilário, Rodrigo J., 2010, Temnocephala pignalberiae Dioni, 1967 (Platyhelminthes, Temnocephalida) from two allopatric populations of Dilocarcinus pagei Stimpson, 1861 (Crustacea, Decapoda) — first record for Brazil, Zootaxa 2613, pp. 15-28 : 17-23

Temnocephala pignalberiae Dioni, 1967

(Figs. 3–37)

Study based on 57 specimens collected: 26 specimens stained in hematoxylin mounted in toto: 8 from Poconé and 18 from Bebedouro; 6 specimens stained in aceto-carmine/fast green mounted in toto: 5 from Poconé and 1 from Bebedouro; 22 extracted cirri mounted in Faure´s medium: 5 from Poconé and 17 from Bebedouro; and 3 slides with eggs mounted in Canada balsam: 2 from Poconé and 1 from Bebedouro.

Table 1 presents morphometric data comparing specimens measured from Poconé and Bebedouro.

Taxonomic summary. Type host and type locality: Dioni (1967) did not indicate the type host and the type locality for this species: “ Trichodactylus orbicularis Meuschen , Río Salado, Santo Tomé, Argentina; Trichodactylus pictus, Madrejón Don Felipe y Laguna Guadalupe, Santa Fe, Argentina; Trichodactylus sp., Madrejón Don Felipe, Santa Fe; Trichodactylus sp., alrededores de Paraná, Entre Ríos; T. pictus y T. orbicularis, Madrejón Don Felipe , Santa Fe; T. pictus, Laguna Guadalupe, Santa Fe”.

Other hosts and localities: Argentina: “ Dilocarcinus pagei Stimpson, 1861 , Laguna Guadalupe (Piedras Blancas), Santa Fe, Argentina ( Damborenea, 1992)”. Brazil (present work): Dilocarcinus pagei in Poconé, State of Mato Grosso and in Bebedouro, State of São Paulo.

Site of infestation: adults found inside the branchial chambers; eggs deposited over the tissue covering the inner upper part of the carapace.

Prevalence: 100%, in both localities, Poconé, MT and Bebedouro, SP.

Specimens deposited: CHIOC Nº 37307 (SBA- 2801-2-2, eggs), CHIOC Nº 37308 (SBA- 2807-1-3, specimen in toto), CHIOC Nº 37309 (SBA- 2799-1-5, cirrus in F), CHIOC Nº 37310 a-b (SBA-3076-1-1 (a), specimen in toto; SBA-3076-1-6 (b), specimen in toto), CHIOC Nº 37311 (SBA- 2944-1-1, cirrus in F); INPA Nº 525 (SBA-3076-1-5: specimen in toto), INPA Nº 526 (SBA- 2945-1-4: cirrus in F), INPA Nº 527 (SBA- 2799-1-3: specimen in toto), INPA Nº 528 (SBA- 2800-1-2: cirrus in F); MLP Nº 6091 (SBA- 2807-1-1: specimen in toto), MLP Nº 6092 (SBA- 2799-1-4, cirrus in F), MLP Nº 6093 (SBA- 2802-2-1, eggs), MLP Nº 6094 (SBA- 2946-1-4: specimen in toto), MLP Nº 6095 (SBA- 2945-1-3, cirrus in F).

Specimens examined: “ Temnocephala pignalberiae , MLP Nº 3126, camaras branquiales, Dilocarcinus (D.) pagei, Laguna Guadalupe, Santa Fe, Argentina, col. 2 Febrero 1987 ”; “ Temnocephala pignalberiae , MLP Nº 3127, camaras branquiales, Sylviocarcinus pictus, Laguna Guadalupe, Santa Fe, Argentina. Col. 2 Febrero 1987 ”; “ Temnocephala pignalberiae , MLP Nº 3127, camaras branquiales, Sylviocarcinus pictus, Laguna Guadalupe (Piedras Blancas), Santa Fe, Argentina. Col. 1 Febrero 1987 ”; and “ Temnocephala pignalberiae , MLP” (slide without collection number, host name, date of collection, and collector indication).

Host specimens deposited: “Coleção de Crustáceos UFRGS Nº 4565 – SBA 3184 – Dilocarcinus pagei, Bebedouro Col. R. J. Ilário ”; “Coleção de Hospedeiros Laboratório de Helmintologia UFRGS – SBA 3185 – Dilocarcinus pagei, Bebedouro. Col. R. J. Ilário. ”

Comments. Dioni (1967) did not indicate having elected and deposited a holotype and paratypes of T. pignalberiae ; consequently, he also did not indicate which of the two species of crabs, D. pagei or S. australis , would be the type host, nor did he indicate which of the five collection localities would be the type locality for the species. Later, Damborenea (1992) and Damborenea & Cannon (2001) collected again T. pignalberiae from the same hosts and from the same localities in Argentina.

Temnocephala pignalberiae is the species with the most perfect elliptical body shape (when properly killed/fixed by formalin 10% formalin 90ºC — compare Figs. 8–11 with Figs. 12 and 13 ) and the smallest tentacles, among the species so far studied. The crabs infested with T. pignalberiae did not have temnocephalan eggs deposited on the external areas of the carapace, abdomen or pereiopods ( Figs. 1 and 2 ). The eggs laid by T. pignalberiae are the most delicate which we have found in any of the species studied. Additionally, these eggs being laid over the tissue which covers the inner upper surface of the carapace were collected by ‘peeling off’ this tissue (Figs. 4 and 5). These eggs have a long, subterminal filament (Fig. 6). In the present paper, specimens of D. pagei , from Poconé and Bebedouro, were infested exclusively by T. pignalberiae , which allowed us to be certain about the morphology and the correct place for the deposition of eggs by this species.

Specimens of T. pignalberiae from these two allopatric populations of D. pagei showed many similarities when compared: above all, the shape of the cirrus, which is the only unarmed (without spines in the introvert) cirrus found in species of Temnocephala . The cirri in specimens from Poconé are proportionally longer, in relation to the length of the prostatic bulbs. The latter have thicker walls and are less elongate than those found in specimens from Bebedouro. In specimens from Poconé the proximal end of the shaft tends to have the rims curved inward, when compared to the rims of the shaft of cirri in the specimens from Bebedouro. The prostatic bulb is more elongated (pyriform) than elliptical, and the rims of the proximal extremity of the shaft are not curved inward ( Figs. 17 and 18 ; 24 and 29).

Temnocephala pignalberiae has only one vaginal sphincter, which appears to be double when observed in whole mounts, because the distal portion of the vagina has very thick walls, and can be clearly observed when DIC illumination is applied to dissected reproductive parts mounted in Faure´s medium ( Fig. 32 ) or in specimens stained with aceto-carmine/fast green ( Fig. 37 ).

Other similarities observed between the specimens from D. pagei , of Poconé and Bebedouro were the shape of the DLSPs, as revealed by SEM ( Figs. 20–21 ); the presence of two large disk glands (paranephrocytes?); and the dorsal position of the vitellarium, which is well superposed to the intestinal sac and has the terminal portions of the branches turning toward its ventral side (Figs. 7 and 34).

Figures

FIGURES 8 – 13. Temnocephala pignalberiae. 8 – 9. specimens from Poconé fixed in hot formalin showing the typical body shape and the red-eyes (black head arrow). 10 – 11. specimens from Bebedouro fixed in hot formalin showing the typical body shape and the red-eyes (black head arrow). Same scale bar to Figs. 8 - 11 = 500 µm. 12. carapace of crab killed with cold ethanol showing the specimens and many eggs cemented to the tissue which covers the inner upper surface of the carapace. Scale bar = 2 mm. 13. specimens killed with cold ethanol, together with the host, showing the altered body shape. Scale bar = 2 mm.

FIGURES 1 – 2. Dilocarcinus pagei, showing the absence of eggs of T. pignalberiae on the external dorsal and ventral surfaces, including the pereiopods. 1. adult female specimen in dorsal view. Scale bar = 1. 5 cm. 2. adult female specimen in ventral view. Scale bar = 1. 5 cm. FIGURES 3 – 7. Temnocephala pignalberiae. 3. live eggs deposited on the tissue (asterisks) covering the inner upper surface of the carapace. Scale bar = 500 µm. 4. fixed eggs cemented to the tissue covering the inner upper surface of the carapace. Scale bar = 1 mm. 5. fixed eggs cemented to the tissue covering the inner upper surface of the carapace, in higher magnification (two asterisks). Scale bar = 500 µm. 6. unhatched egg showing the filament (black head arrow). Scale bar = 250 µm. 7. adult, killed in hot formalin showing the correct shape of the body, stained in aceto-carmine / fast green. Scale bar = 1 mm.

FIGURES 14 – 18. Temnocephala pignalberiae. 14. incomplete diagram of an adult specimen, ventral view, showing: adhesive disk (ad), anterior testis (at), excretory ampullae (ea), dorsal vitelline glands (vg), Haswell glands (hg), large disk glands (paranephrocytes?) (ldg (p )), mouth (m), posterior testis (pt), pharynx (ph), and tentacles (t). Scale bar = 1 mm. 15. female reproductive organs: anterior portion of the vaginal sphincter (avs), genital atrium (ga), ovary (ov), posterior portion of the vaginal sphincter (pvs), vagina (va), vesicula resorbens (vr), vitelline glands duct (vgd), seminal receptacles (sr). Scale bar = 50 µm. 16. male reproductive system: cirrus (c), opening in the prostatic bulb wall (black head arrow), prostatic bulb (pb), prostatic cells (pc), prostatic secretion (ps), seminal vesicle (sv), and vasa deferentia (vd), Scale bar = 50 µm. 17. cirrus of specimens from Poconé, proximal limit of the introvert (arrow), proximal shaft base curving in. Scale bar = 25 µm. 18. cirrus of specimens from Bebedouro, proximal limit of the introvert (arrow), proximal shaft base not curving in. Scale bar = 25 µm.

FIGURES 32 – 33. Temnocephala pignalberiae. 32. partial view of the reproductive system, observed with Nomarski´s DIC microscopy: male organs – seminal vesicle (sv), prostatic bulb (pb), and prostatic secretion (ps); female organs – ovary (ov), distal vagina (dv), vaginal sphincter with the anterior vaginal portion (avs), and the posterior vaginal portion (pvs). Scale bar = 50 µm. 33. enlarged prostatic bulb showing the wall openings (black arrows), the prostatic secretion (ps), and cirrus (c), both from a specimen from Poconé. Scale bar = 50 µm.

FIGURES 34 – 37. Temnocephala pignalberiae. 34. adult specimen pressed between slide and cover slip, showing that too much pressure may be good to allow all characters to be observed in the same focusing plane, but alters the body shape. Scale bar = 1 mm. 35. Haswell glands (black head arrows). Scale bar = 200 µm. 36. mouth (m), mouth sphincter (ms), and pharyngeal sphincter (ps). Scale bar = 200 µm. 37. male and female reproductive system: anterior portion of the vaginal sphincter (avs), cirrus (c), deferent duct (dd), ejaculatory duct (ed), genital pore (gp), genital atrium (ga), ovary (ov), posterior portion of the vaginal sphincter (pvs), prostatic bulb (pb), seminal receptacles (sr), seminal vesicle (sv), vagina (va), and vesicula resorbens (vr). Scale bar = 100 µm.

FIGURES 19 – 21. Temnocephala pignalberiae seen with SEM. 19. entire specimen from Poconé, showing the dorsolateral ‘ excretory’ syncytial plates (black head arrows) and position of excretory pores (n – white arrows). Scale bar = 200 µm. 20. left DLSP, seen in a specimen from Poconé, (n – white arrow). Scale bar = 100 µm. 21. left DLSP, seen in a specimen from Bebedouro, (n – white arrow). Scale bar = 100 µm.