Trichodina magna Van As and Basson, 1989 (Ciliophora: Peritrichia) from cultured Nile tilapia in the state of Santa Catarina, Brazil/Trichodina magna Van As e Basson, 1989 (Ciliophora: Peritrichia) em tilapia do Nilo cultivada no Estado de Santa Catarina, Brasil.
Trichodinids are commonly found parasitizing marine (Xu et al., 2001) and freshwater fishes (Arthur and Lom, 1984a). Lom (1958) reported on the specific characteristics that have been considered in trichodinids. Since the studies of Lom (1960, 1970) in the surroundings of Prague, new species of Trichodina Ehrenberg, 1830 have been described in North America (Wellborn, 1967), Cuba and Russia (Arthur and Lom, 1984a, b), South Africa (Basson and Van As, 1991), Japan (Imai et al., 1991), India (Asmat and Haldar, 1998), Germany (Dobberstein and Palm, 2000), Egypt (Al-Rasheid et al., 2000), China and Korea (Xu et al., 2001). In pond-reared fishes, they have been found on catfish (Basson and Van As, 1991), on perch, and on roach (Halmetoja et al., 1992), in tilapia (Van As and Basson, 1992), in carp (Nikolic and Simonovic, 1998), in eel (Madsen et al. (2000), and in marine cultivated fishes in Korea (Xu et al., 2001). In Brazil, Vargas et al. (2000) and Tavares-Dias et al. (2001) have reported their presence in several cultured freshwater fishes. However, under inadequate conditions of handling, these ciliates may proliferate being responsible for diseases (Madsen et al., 2000; Martins et al., 2002). Nothing is known about trichodinid species from pond-reared fishes in Brazil. In this study, Trichodina magna Van As and Bassson, 1989, found on the skin and gills of tilapia, Oreochromis niloticus Linnaeus, 1758 collected in three regions in the State of Santa Catarina, Brazil, is described.
2. Material and Methods
Specimens of O. niloticus were collected in farms situated in the municipalities of Blumenau (26[degrees] 55' 10" S and 49[degrees] 03' 58" W) (n = 48), Joinville (26[degrees] 18' 16" S and 48[degrees] 50' 44" W) (n = 63), and Ituporanga (27[degrees] 24' 52" S and 49[degrees] 36' 09" W) (n = 35), Santa Catarina, Brazil, from October 2004 through June 2005. Wet smears of skin and gills were prepared in the field and examined under microscope. When parasites were present the smears were air dried and impregnated with Klein's dry silver method for observation of the adhesive disc as suggested by Lom (1958). Other smears were stained with Giemsa's solution to reveal the nuclear apparatus. The span of the denticle was measured from the tip of blade to the tip of ray as described by Arthur and Lom (1984a). The body diameter is the dimension of the adhesive disc plus the border membrane, and the diameter of the striated membrane is the distance from the outer border of the adhesive disc to the denticulate ring. Wet mounts from the specimens preserved in 5% formalin solution were studied for the observation of adoral ciliature. All measurements are in micrometers and follow the recommendations of Lom (1958) and Van As and Basson (1989). Arithmetic means [+ or -] standard deviation is followed, in parentheses, by the minimum and maximum values and number of specimens or structures measured. t-test was applied to compare the measurements (from the averages) of these specimens with the original description.
From a total of 146 examined fish, 36 were parasitized on the skin, 14 in the gills and 33 on the skin and gills. The parasite was characterized as a large trichodinid with disc-shaped body; convex adoral surface with ciliature of about 370[degrees] [+ or -] 6.7 (360-384) measured in 17 specimens; central contractile vacuole; aboral side with slightly concave adhesive disc provided by 26.0 [+ or -] 1.2 (23-29, 55) denticles and central area of the adhesive disc provided with dark granules. The denticles are inserted into one another characterized by blade slightly falcate with a smooth anterior margin; central part very long and sharp-pointed in Giemsa-stained specimens, but slightly robust in silver-impregnated specimens reaching y + 1 axis; ray long and slender anteriorly directed but do not pass y + 1 axis, slightly curved tapering gradually along its length provided by a relatively long apophysis (Figure 1).
Wet mounted measurements: body 79.5 [+ or -] 13.8 (56-100, 26) in diameter; adhesive disc diameter 58.7 [+ or -] 11.5 (44-76, 26); denticulate ring diameter 38.3 [+ or -] 7.4 (28-48, 26); length of denticles 20.8 [+ or -] 3.3 (16-24, 28), length of blade 7.3 [+ or -] 1.7 (6-15, 28), width of central part 4.6 [+ or -] 0.8 (4-7, 28), length of ray 12.0 [+ or -] 1.9 (9-15, 28), denticle span 30.5 [+ or -] 5.1 (24-39, 28).
Air dried measurements: body 84.31 [+ or -] 12.6 (47-104, 55) in diameter surrounded by a border membrane 7.2 [+ or -] 1.5 (4-12, 55) wide; width of striated membrane 11.0 [+ or -] 2.8 (8-17, 55); adhesive disc diameter 60.7 [+ or -] 10.0 (33-83, 55); denticulate ring diameter 38.5 [+ or -] 6.8 (28-48, 55); radial pins per denticle 7.7 [+ or -] 0.6 (7-9, 46); length of denticles 20.3 [+ or -] 3.1 (15-26, 151), length of blade 7.0 [+ or -] 1.1 (3-8, 151), width of central part 3.6 [+ or -] 0.7 (2-6, 151), length of ray 11.3 [+ or -] 2.3 (8-15, 151), length of ray apophysis 1.1 [+ or -] 0.4 (1-2, 151); denticle span 28.6 [+ or -] 3.9 (17-36, 151). Macronucleus horseshoe-shaped 49.1 [+ or -] 10.3 (24-64, 28) in external diameter; 9.9 [+ or -] 2.5 (7-16, 28) thickness; distance between the terminations of macronucleus 10.5 [+ or -] 3.4 (7-17, 28). Micronucleus not detected.
[FIGURE 1 OMITTED]
Up until the present, in Brazil, trichodinids have been referred to as Trichodina sp. The following species of trichodinids are presently to be found in tilapia: T. pediculus Ehrenberg, 1838 (see Basson et al., 1983); T. nigra Lom, 1960; T. acuta Lom, 1961; T. heterodentata Duncan, 1977; Trichodinella tilapiae Duncan, 1977; T. centrostrigeata Basson, Van As and Paperna, 1983; T. minuta Basson, Van As and Paperna, 1983; Paratrichodina africana Kazubski and El-Tantawy, 1986; Trichodina magna Van As and Basson, 1989; T. velasquezae Bondad-Reantaso and Arthur, 1989 (see Asmat and Haldar, 1998); T. compacta Van As and Basson, 1989; T. migala Van As and Basson, 1989; T. linyanta Van As and Basson, 1992 and T. kalimbeza Van As and Basson, 1992 were described.
Trichodina magna, reported in this study resembles T. fultoni Davis, 1947; T. funduli Wellborn 1967; T. hoffmanii Wellborn, 1967; T. noturi Wellborn, 1967; T. platyformis Davis, 1947; T. reticulata Hirschmann and Partsch, 1955 (see Wellborn, 1967); T. mutabilis Kazubski and Migala, 1968 (see Lom, 1970); T. rostrata Kulemina, 1968 (see Arthur and Lom, 1984); T. carassii Lian-xiang, 1990 and T. claviformis Dobberstein and Palm, 2000 in the body diameter and number of denticles. Trichodina funduli, T. platyformis, T. reticulata, T. mutabilis, T. izumovae Arthur and Lom, (1984) showed similar diameter of the adhesive disc, denticulate ring and macronucleus. The specimens of T. magna described herein differ from these species in having different shape and length of denticles, blade and ray in which are important specific diagnostic characteristics for trichodinids. In spite of the similarity in the body diameter, adhesive disc and denticulate ring, T. heterodentata, described by Duncan (1977), has a smaller number of denticles and smaller denticle measurements when compared to the present specimens. Moreover, T. heterodentata differs from the specimens of T. magna from Santa Catarina in having considerably more variability in the shape of the denticle. The specimens of T. magna used in the original description (Van As and Basson, 1989) are similar to the present material (Table 1). Specimens from Santa Catarina, however, have smaller macronucleus diameter when compared to the ones described by Van As and Basson (1989). The apophysis morphology of the prominent ray of the denticle had a similar structure, although Van As and Basson did not give its measurements. The micronucleus was not detected corroborating the findings of Van As and Basson (1989). Another point that must be considered is that, in silver-impregnated specimens, the length of the apophysis of the ray may vary or may not even be detectable. Based on this information, commented by Vans As and Basson (1989), the apophysis measurements in Giemsa-stained specimens were performed in this study. The unique most distinguishable difference was the fact that the ray of denticle is anteriorly directed, extending over the y + 1 axis in the specimens of Van As and Basson (1989) (Figure 2) while in the present description the ray is situated between the y and y + 1 axes. In spite of the difference in position of the ray in relation to the axes and the lack of significant difference in morphology these specimens must be considered members of T. magna. This study shows the variability that can be seen in the different populations of trichodinid species, corroborating the observations of Van As and Basson (1989).
[FIGURE 2 OMITTED]
Acknowledgments--To CNPq for financial support (300281/2004-8, 470100/2004-4). To Walter A. Boeger (Zoology Department, UFPR, PR, Brazil) for his suggestions. To Roberto Hoppe (Fundacao 25 de Julho), Sergio Tamassia (Epagri), Pesque-pague Erimar, Pesque-pague Fernandao, Pesque-pague Divisa, Nilotica Aquacultura, Amilton Luiz, Aurima Knaul, Jair Curti Vegge, Joao Carlos Desordi, Valerio Burini for fish donation. To Gastao Reis and Heloisa Laterca for the language revision.
Received March 9, 2006--Accepted June 28, 2006--Distributed February 29, 2008 (With 2 figures)
AL-RASHEID, KAS., ALI, MA., SAKRAN, T., BAKI, AAA. and GHAFFAR, FAA., 2000. Trichodinid ectoparasites (Ciliophora: Peritrichida) of some River Nile fish, Egypt. Parasitol. Int., vol. 49, p. 131-137.
ARTHUR, JR. and LOM, J. 1984a, Trichodinid protozoa (Ciliophora: Peritrichida) from freshwater fishes of Rybinsk Reservoir, USSR. J. Protozool., vol. 31, no. 1, p. 82-91.
-, 1984b. Some trichodinid ciliates (Protozoa: Peritrichida) from Cuban fishes, with a description of Trichodina cubanensis n.sp. from the skin of Cichlasoma tetracantha. Trans. Am. Microsc. Soc., vol. 103, no. 2, p. 172-184.
ASMAT, GSM. and HALDAR, DP., 1998. Trichodina mystusi, a new species of trichodinid ciliophoran from Indian estuarine fish, Mystus gulio (Hamilton). Acta Protozoool., vol. 37, p. 173-177.
BASSON, L. and VAN AS, JG. 1991. Trichodinids (Ciliophora: Peritrichia) from a calanoid copepod and catfish from South Africa with notes on host specificity. Syst. Parasitol., vol. 18, p. 147-158.
BASSON, L., VAN AS, JG. and PAPERNA, I., 1983. Trichodinid ectoparasites of cichlid and cyprinid fishes in South Africa and Israel. Syst. Parasitol., vol. 5, p. 245-257.
DOBBERSTEIN, RC. and PALM, HW. 2000. Trichodinid ciliates (Peritrichida: Trichodinidae) from the Bay of Kiel, with description of Trichodina claviformis sp. n. Folia Parasitol., vol. 47, p. 81-90.
DUNCAN, BL. 1977. Urceolariid ciliates, including three new species, from cultured Phillipine fishes. Trans. Am. Microsc. Soc., vol. 96, no. 1, p. 76-81.
HALMETOJA, A., VALTONEN, ET. and TASKINEN, J. 1992. Trichodinids (Protozoa) on fish from central finnish lakes of differing water quality. Aqua Fenica, vol. 22, no. 1, p. 59-70.
IMAI, S., MIYAZAKI, H. and NOMURA, K. 1991, Trichodinid species from the gill of cultured Japanese eel, Anguilla japonica, with the description of a new species based on light and scanning electron microscopy. Europ. J. Protistol., vol. 27, p. 79-84, March 28.
LOM, J. 1958. A contribution to the systematics and morphology of endoparasitic trichodinids from amphibians, with a proposal of uniform specific characteristics. J. Protozool., vol. 5, no. 4, p. 251-263.
LOM, J., 1960. Trichodina reticulata Hirschmann and Partsch 1955 from crucian carp and T. domerguei f. latispina Dogel 1940 from Diaptomus. Vestn. Cs. Zool. Spol., vol. 24, no. 3, p. 246-257.
LOM, J., 1970. Observations on trichodinid ciliates from freshwater fishes. Arch. Protistenk. Bd., vol. 112, p. 158-177.
MARTINS, ML., ONAKA, EM., MORAES, FR., BOZZO, FR., PAIVA, AMFC. and GONCALVES, A., 2002. Recent studies on parasitic infections of freshwater cultivated fish in the State of Sao Paulo, Brazil. Acta Scientiarum, vol. 24, no. 4, p. 981-985.
MADSEN, HCK., BUCHMANN, K. and MELLERGAARD, S. 2000. Trichodina sp. (Ciliophora: Peritrichida) in eel Anguilla anguilla in recirculation systems in Denmark: host-parasite relations. Dis. Aquat. Org., vol. 42, 149-152.
NIKOLIC, VP. and SIMONOVIC, PD., 1998. Seasonal dynamics of carp infestation by Trichodina nobilis Chen. 1963 (Peritrichida, Ciliata) in two fish-ponds in Banat. Tiscia, vol. 31, p. 59-61.
VAN AS, JG. and BASSON, L., 1989. A further contribution to the taxonomy of the Trichodinidae (Ciliophora: Peritrichia) and a review of the taxonomic status of some fish ectoparasitic trichodinida. Syst. Parasitol., vol. 14, p. 157-179.
VARGAS, L., POVH, JA., RIBEIRO, RP. and MOREIRA, HLM., 2000. Prevalencia de ectoparasitos en tilapia del Nilo (Oreochromis niloticus) de origen tailandesa de Maringa, Parana. Arq. Cien. Vet. Zool. UNIPAR, vol. 3, no. 1, p. 32-37.
TAVARES-DIAS, M. MARTINS, ML. and MORAES, FR., 2001. Fauna parasitaria de peixes oriundos de "pesque-pague" do municipio de Franca, Sao Paulo, Brasil I Protozoarios. Rev. Bras. Zool., vol. 18, no. 1, p. 67-79.
XU, K., SONG, W., WARREN, A. and CHOI, JK. 2001. Trichodinid ectoparasites (Ciliophora: Peritrichida) of some marine fishes from coastal regions of the Yellow Sea and Bohai Sea. Syst. Parasitol., vol. 50, p. 69-79.
WELLBORN, T.L., 1967. Trichodina (Ciliata: Urceolariidae) of freshwater fishes of the Southeastern United States. J. Protozool., vol. 14, no. 3, p. 399-412.
Martins, ML. * and Ghiraldelli, L.
Laboratorio de Diagnostico e Patologia em Aquicultura, Departamento de Aquicultura, Centro de Ciencias Agrarias--CCA, Universidade Federal de Santa Catarina--UFSC, Rod. SC 404, Km 3, CP 476, CEP 88040-900, Florianopolis, SC, Brazil
* e-mail: email@example.com
Table 1. Comparative measurements of Trichodina magna. Van As and Characters Present work Basson (1989) (1) Body (D) 84.3 (47-104) a 99.1 (71-112) b Adhesive disc (D) 60.7 (33-83) a 81.7 (60-95) b Border membrane (W) 7.2 (4-12) a 8.9 (6-14) b Denticulate ring (D) 38.5 (24-56) a 50.0 (36-57) b Denticle number 26.0 (23-29) a 25.0 (24-27) a Pins/denticle 7.7 (7-9) a 11.0 (10-13) b Denticle span 28.6 (17-36) a -- Denticle (L) 20.3 (15-26) a 10.9 (7-14) b Blade (L) 7.0 (3-8) a 8.6 (6-11) b Central part (W) 3.6 (2-6) a 5.6 (4-7) b Ray (L) 11.3 (8-15) a 13.0 (8-13) a Macronucleus (D) 49.1 (24-64) a 62.2 (47-82) b Macronucleus (TH) 9.9 (7-16) 8.1 (6-10) Macronucleus (LT) 10.5 (7-17) 14.9 (7-38) Adoral ciliature 360-384 400[degrees] Van As and Characters Basson (1992) (2) Body (D) 82.3 (62-98) a Adhesive disc (D) 69.2 (46-80) a Border membrane (W) 6.2 (4-8) a Denticulate ring (D) 42.9 (31-52) c Denticle number 27.0 (24-30) b Pins/denticle 12.0 (9-14) c Denticle span 21.5 (15-25) a Denticle (L) 9.5 (7-12) c Blade (L) 7.6 (6-9) a Central part (W) 3.2 (1-4) a Ray (L) 10.7 (7-14) a Macronucleus (D) Macronucleus (TH) -- Macronucleus (LT) -- Adoral ciliature 407-410[degrees] (1) From Oreochromis andersoni, O. mossambicus, Tilapia rendalli rendalli, T. rendalli swierstrae, T. sparrmanii; (2) from O. andersoni, T. rendalli rendalli, Serranochromis angusticeps. (D) diameter, Wwidth, (L) length, (TH) thickness, (LT) length between terminations of macronucleus. Means followed by the same letters are not significantly different (P > 0.05)