Temnocephala caddisflyi, Amato, José F. R., Amato, Suzana B., Seixas, Samantha A., Vidigal, Teofânia H. D. A. & Andrade, Cynthia De Paula, 2011

Amato, José F. R., Amato, Suzana B., Seixas, Samantha A., Vidigal, Teofânia H. D. A. & Andrade, Cynthia De Paula, 2011, Trichoptera — the newest insect order host of temnocephalans (Platyhelminthes, Temnocephalida) and the description of a new species of Temnocephala from Brazil, Zootaxa 2975, pp. 47-58 : 51-57

Temnocephala caddisflyi n. sp. Amato, Amato & Seixas

(Figs. 6–20, 24–29, and 32–34)

Description. Based on 31 collected specimens: 12 whole mounted adult specimens; 5 juveniles; 2 specimens mounted on stubs for Scanning Electron Microscope (SEM); 10 dissected cirri mounted in (F); 2 slides with eggs in Canada balsam; 12 specimens measured.

External characteristics. Body (without tentacles) (Fig. 7) 1.15–2.27 mm (1.80 mm ± 383) long, 0.98– 1.63mm (1.27 mm ± 212) wide; adhesive disk ventral, subterminal, partially covered by body (Fig. 7) 230–410 (346 ± 49) long, 270–430 (346 ± 49) wide; disc peduncle 180–300 (238 ± 45) wide. Eyespots with red pigmentation (observations made on live specimens or fixed with hot formalin) (Fig. 7). Two dorsolateral, epidermal ‘excretory’ syncytial plates, large and saddle shaped ( Figs. 16–17 ), left plate 361.7 long, 175.7 wide; ratio of length of DLSPs /total body length, without tentacles, 5: 1. Excretory pore in the anterior portion, near the internal limit ( Fig. 17 —n).

Glands. Rhabditogen glands forming bunches (average 16 cells), in lateral fields of body ( Fig. 9 —black head arrows; 11—rg), 35 – 55 (47 ± 7) in diameter, ducts conspicuous. Two groups of five Haswell glands, showing little affinity with hematoxylin, in front of the brain transverse band, diameter of largest cell 73–140 (94 ± 19). Disc glands between adhesive disc and genital complex, forming two, lateral bunches extending from posterior testes to margin of adhesive disc ( Figs. 9 —black arrows; 12—dg), including pair, of large, round, more central cells (paranephrocytes?), 53–68 (59 ± 5) long ( Figs. 9 —white head arrows; 12—ldg (p)).

Reproductive system. Female. Ovary located between vagina and vesicula resorbens, 90–168 (134 ± 24; 9) long, 80–128 (106 ± 17; 9) wide ( Fig. 14 ). Vitellarium arborescent, completely covering intestine dorsally ( Fig. 13 ), ventral region partially covered in lateral margins; vagina classified as ‘complex’ (see Terminology in M&M) with the proximal portion smaller than the distal portion; middle portion spheroid, with muscular wall not so strongly developed, 15–30 (25 ± 5; 8), and the distal portion ( Fig. 14 ), 250 – 537.5 (365 ± 85; 10) long; total vagina maximum width 62.5 – 162.5 (96 ± 34; 10); vaginal sphincter small, asymmetrical ( Fig. 14 —avs and pvs) 30 – 65 (45 ± 12; 9) in total diameter; diameter of anterior portion 27.5 – 50 (38 ± 9; 9), diameter of posterior portion 7.5 – 25 (17 ± 5; 9); vesicula resorbens usually full of sperm ( Fig. 14 —vr), 113–283 (175 ± 175; 11) long; 25–258 (192 ± 67; 11,) wide; wall thickness 2.5–12.5 (6.8 ± 7; 11) thick. Eggs pedunculate (Fig. 6), predominantly on the dorsal side of the thoracic segments ( Figs. 4 and 5 ), 415–553 (486 ± 51; 10) long, 237–296 (269 ± 23; 10) wide; filament lateral (Fig. 6—white arrow), peduncle 99 – 276 (180 ± 58; 10) long; opercular plates inconspicuous.

Male. Testes four, usually rounded, slightly oblique; both deferent vessels united in large pyriform, thickwalled, seminal vesicle, 83–248 (165 ± 48; 11) long, 48–93 (61 ± 15) wide; prostatic bulb ( Figs. 24 – 25 ) with thick, muscular walls, 118–230 (171 ± 31; 11) long, 65–143 (90 ± 24; 11) wide, enclosed as well as the cirrus, in a muscular ‘sleeve-like’ tissue, sometimes showing folds; proximal portion with few large cells and prostate secretion in the distal portion; prostate bulb receives the ejaculatory duct laterally ( Fig. 25 ); prostatic bulb wall thickness 5 – 17.5 (3.8; 11); cirrus classified as ‘complex’ (see Terminology in M&M), composed of long shaft and long introvert, both curved in lateral view, directed ventrally, 530–700 (560 ± 88; 9) long, shaft 270–540 (398 ± 84; 9) long, shaft maximum width at base 37.5–87.5 (61 ± 17; 9) ( Fig. 18 ); introvert curved (approximately 138º) at midregion, 150–185 (145 ± 12; 9) long; introvert ventral length 127.5–155 (140 ± 8; 8); introvert dorsal length 142.5– 185 (169 ± 15; 9); maximum introvert width at level of swelling, 30–40 (32 ± 4; 9); introvert´s swelling portion length, at ventral side 22.5–37.5 (28 ± 4.7; 8); introvert´s swelling portion length, at dorsal side 32.5–40 (35 ± 3.3; 8), observed in progressive focusing planes with the Nomarski´s DIC microscopy ( Figs. 26–29 ). The introvert´s swelling shows approximately 57 longitudinal rows of fine spines and approximately 50 spines per row; each row can be seen as teeth of a comb, with the ‘handle’ positioned backwards. Each spine in the perimeter of the swelling portion is, approximately, 3.7 µm long. Bottom of introvert´s swelling portion receives a group of larger spines which are placed circularly on the inner wall. Among these are four still wider, ‘blade-like’ spines placed in the cardinal positions ( Figs. 26 – 29 ) and resting on the wall of the introvert. Proximal limit of introvert marked by a narrowing of the lumen´s diameter, due to a pronounced constriction and is seen from the side as two spikes of pronounced length ( Fig. 19 —black arrow). Shaft and introvert curvature angles of 158º and 135º, respectively. Retractor muscles of different aspect in ventral and dorsal sides of the introvert. Dorsal retractor muscle 52.5 – 92.5 (67 ±11; 9) long, 25 – 42.5 (32 ± 6; 9) wide, forming a distal globular thickening capable of projecting itself forward ( Fig. 15 ; 19—fprm), when observed entering the distal portion of the vagina, in which it enters first, ahead of the spined swelling distal portion (Fig. 34); ventral retractor muscle wider at mid-length of the introvert ( Fig. 19 —rm).

Ratio between total body length, without tentacles/ total length of cirrus 3.2: 1; ratio between total length of cirrus/ maximum width of shaft´s base 9.2: 1; ratio between total length of cirrus/ total length of introvert 3.9: 1.

Figures

FIGURES 16 – 17. Temnocephala caddisflyi n. sp. (SEM). 16. Total body showing the posterior margin of the ‘ saddle-shaped’, dorsolateral, ‘ excretory’ syncytial plates (white arrows) and nephridiopores (white head arrows) (n). Scale bar = 200 µm. 17. Left, dorsolateral, ‘ excretory’ syncytial plate (black head arrows) and the nephridiopore (white head arrow) (n). Scale bar = 20 µm.

FIGURES 9 – 10. Temnocephala caddisflyi n. sp. juvenile cleared in lactophenol. 9. Juvenile showing rhabditogenic glands (black head arrows); disc glands (black arrows); limit between rhabditogenic glands and disc glands (white arrows); two large disc glands (paranephrocytes?) (white head arrows). Scale bar = 100 µm. 10. Testicular region showing the introvert already formed (white head arrow). Scale bar = 100 µm.

FIGURES 11 – 15. Temnocephala caddisflyi n. sp. 11. Incomplete diagram of juvenile specimen, dorsal view, showing rhabditogenic glands (rg), extending along the sides of intestinal sac, still uncovered by vitellaria, and ducts entering tentacles. Scale bar = 100 µm. 12. Incomplete diagram of the posterior region of a juvenile specimen, dorsal view, showing adhesive disc glands (dg), including the pair of larger glands (paranephrocytes?) between testes (ldg (p )). Scale bar = 100 µm. 13. Incomplete diagram of an adult specimen showing adhesive disk (ad), anterior testes (at), excretory vesicle (ev), Haswell glands (hg), mouth (m), pharynx (ph), posterior testis (pt), vitelline glands (vg), and tentacles (t). Scale bar = 250 µm. 14. Female reproductive complex, showing anterior portion of the vaginal sphincter (avs), genital atrium (ga), posterior portion of the vaginal sphincter (pvs), vesicula resorbens (vr), ovary (ov), vagina proximal portion (pva), vagina middle portion (mva), vagina distal portion (dva), vesicula intermedia (vi), and vitelline duct (vd). Scale bar = 50 µm. 15. ‘ Complex’ cirrus, showing shaft, introvert, and the path of movement that the dorsal retractor muscle is capable of doing (arrow), during the introduction in the vagina. Scale bar = 100 µm.

FIGURES 3 – 5. Caddisfly larvae genus Baripenthus. 3. Larva inside the case. Scale bar = 5 mm. 4. Anterior portion of a larva removed from the case, showing the dorsal area of egg deposition. Scale bar = 1 mm. 5. Another specimen removed from the case, dorsal view, showing in higher magnification, a larger number of eggs. Scale bar = 500 µm.

FIGURES 24 – 29. Temnocephala caddisflyi n. sp., prostatic bulb and introvert observed in different focusing planes with DIC. 24. Prostatic bulb showing the orifice entering prostatic secretion (arrow), prostatic secretion (ps), prostatic cells (pc), and the prostatic vesicle (pv). Scale bar = 50 µm. 25. Prostatic bulb (pb) and seminal vesicle (sv) with the ejaculatory duct (ej) entering the prostatic bulb. Scale bar = 50 µm. 26 – 29. Distal portion of the introvert, showing the large spines and the shorter swelling portion seen in different focusing planes. Scale bars = 10 µm.

FIGURES 18 – 20. Cirrus of Temnocephala caddisflyi n. sp. from trichopterans, seen with Nomarski´s differential interference contrast microscopy (DIC). 18. Photomicrograph of the entire ‘ complex’ cirrus, Scale bar = 100 µm. 19. Limit of the introvert portion with the shaft (black arrow), forward projecting dorsal retractor muscle (fprm), and ventral retractor muscle (rm). Scale bar = 50 µm. 20. Introvert´s swelling portion (ii) and the long spines which run along the inner wall, showing the rows of spines. Scale bar = 10 µm. FIGURES 21 – 23. Cirrus of Temnocephala curvicirri from belostomatid hemipterans, seen with DIC. 21. Entire ‘ complex’ cirrus. Scale bar = 200 µm. 22. Limit of the introvert portion with the shaft (arrow), forward projecting dorsal retractor muscle (fprm), and ventral retractor muscle (rm). Scale bar = 50 µm. 23. Distal introvert´s swelling portion (ii), showing the rows of spines. Scale bar = 10 µm.