Some digenetic trematodes found in a loggerhead sea turtle (Caretta caretta) from Brazil

1. Diaschistorchis pandus (Braun, 1901) Johnstone, 1913 (Fig. 1) Site of infection: stomach.

Fig. 1

Voucher specimen deposited: CHIOC 38973.

Remarks: This trematode has been found in loggerheads sea turtles from Australia (Braun, 1901), USA (Pratt, 1914; Greiner, 2013), Egypt (Sey, 1977) and Tunisia (Karaa et al., 2019). In Green sea turtles (Chelonia mydas) from Australia (Johnstone, 1913), USA (Greiner, 2013). In Halksbill sea turtles (Eretmocheys imbricata from Australia (Johnstone, 1913) and India (Chattopadhyaya, 1972; Mehrotra & Gupta, 1976). In the Neotropical region (Central and South America), this trematode was already found in green sea turtles from Brazil (Werneck & Silva, 2015), in hawksbills sea turtles from Bermuda (Barker, 1922), Cuba (Vigueras, 1955), Puerto Rico (Fischthal & Acholonu, 1976; Dyer et al., 1995) and Brazil (Werneck et al., 2015) and loggerhead sea turtle from Brazil (present report).

Measurements: (n = 23) Body 7.75 ± 1.07 (6.46 – 9.33) mm long by 3.23 ± 0.35 (2.83 – 3.66) mm wide; oral sucker 961.9 ± 143.8 (727 – 1,201) long by 984 ± 143.9 (871 – 1,220) wide; testis number 16.6 ± 0.89 (16 – 18); ovary 318 ± 48.0 (252 – 364) long by 342.8 ± 82.4 (232 – 430) wide; cirrus sac 680.4 ± 109.6 (575 – 900) long by 225.3 ± 54.5 (156 – 302)

The morphological characteristics are compatible with the taxonomic key proposed by Blair (2005a) and Mehrotra and Gupta (1976), comparisons were made with the article by Dyer et al. (1995). Our specimens are comparable to those described, except the size of the body width and oral sucker, that are larger than those reported by Dyer et al. (1995).

2. Cymatocarpus solearis (Braun, 1899) Braun, 1901 (Fig. 2) (probably Synonym: Cymatocarpus undulatus Looss, 1899) Site of infection: stomach.

Fig. 2

Voucher specimen deposited: CHIOC 38975.

Remarks: According to Blair and Limpus (1982), C. solearis has already been found in loggerheads sea turtles from the Mediterranean coast of Egypt and from USA (Florida) (Looss, 1899; Linton, 1910; Pratt, 1914; Luhman, 1935), in olive ridleys from Japan (Oguro, 1942) and green sea turtles from Mexico (Caballero, 1959). In Brazil it has already been reported in green sea turtles (Werneck & Silva, 2015), hawksbills sea turtles (Werneck et al., 2015) and in loggerhead sea turtle (present report).

Measurements: (n = 36) Body 4.86 ± 0.83 (3.36 – 5.89) mm long by 1.30 ± 0.12 (1.12 – 1.47) mm wide; oral sucker 198.3 ± 50.1 (133 – 245) long by 231.5 ± 55.2 (161 – 291) wide; ventral sucker 262.5 ± 46.7 (171 – 301) long by 275.2 ± 55.9 (196 – 327) wide; pharynx 275.7 ± 187.6 (157 – 492) long by 72.5 ± 25.5 (46 – 107) wide; oesophagus 1,094.8 ± 149.3 (936 – 1296) long by 79 ± 18.7 (61 – 98) wide; anterior testis 249.2 ± 56.2 (183 – 310) long by 238.7 ± 50.0 (168 – 290); posterior testis 256 ± 60.7 (176 – 338) long by 249.6 ± 30.3 (217 – 281); ovary 204.3 ± 64.2 (142 – 321) long by 208.5 ± 49.8 (118 – 267) wide

The morphological characteristics are compatible with the taxonomic key proposed by Pojmanska (2008) and comparisons were made with the article by Blair and Limpus (1982), Caballero (1959) and Grano-Maldonado and Álvarez-Cadena (2010). The morphometric analyses of our specimens are comparable to those described by Blair and Limpus (1982) and Caballero (1959) although they were larger than largest fluke by Grano-Maldonado and Álvarez-Cadena (2010). Principal variations occurred for the size of ventral sucker, pharynx and ovary from those described by Blair and Limpus (1982).

3. Rhytidodes gelatinosus (Rudolphi, 1819) Looss, 1901 (Fig. 3) Site of infection: stomach.

Fig. 3

Voucher specimen deposited: CHIOC 38974.

Remarks: R. gelatinosus is a wide distributed trematode. It has been reported from loggerheads sea turtles, green sea turtles and halksbill sea turtles, from Mediterranean sea, Morocco, USA, Puerto Rico, Cuba, Panama, India, Pakistan, New Guinea and Australia (see revision in Blair & Limpus 1982), also reported in loggerheads sea turtles from Brazil (Viana, 1924; Travassos et al., 1969, present report), Egypt (Looss, 1901; Looss, 1902; Sey, 1977), USA (Greiner, 2013), , More recently in Italy (Manfredi et al., 1998; Santoro et al., 2010; Gracan et al., 2012) and Portugal (Madeira Archipelago); Valente et al., 2009), in green sea turtle from Brazil, (Werneck & Silva, 2015).

Measurements: (n=2) Body 5.31 (4.94 – 5.68) mm long by 1.27 (1.20 – 1.34) mm wide; oral sucker 355 (318 – 392) long by 469 (403 – 535) wide; pharynx 180 (160 – 200) long by 167 (147 – 187) wide; oesophagus 834 (676 – 992) long by 76 (73 – 79) wide; acetabulum 234.5 (214 – 255) long by 187 (181 – 193); ovary 175 (169 – 181) long by 225 (204 – 246) wide; cirrus sac 309 long by 183; anterior testis 249.2 ± 56.2 (183 – 310) long by 238.7 ± 50.0 (168 – 290); posterior testis 371 (338 – 404) long by 272.5 (244 – 301);

The morphological characteristics are compatible with the taxonomic key proposed by Blair (2005b) and the original description by Looss (1901). Our specimens are similar to those described by Blair and Limpus (1982), except that they are smaller.

Published information concerning species of parasites of the loggerhead from the Neotropical region, Gulf of Mexico and USA (Florida) is summarized in Table 1 and Table 2. The present report contributes to the knowledge on marine loggerheads helminth fauna and their geographical distribution.