Helminth Component Community of the Loggerhead Sea Turtle,Caretta caretta,From Madeira Archipelago, Portugal

Abstract

The helminth fauna of pelagic-stage loggerhead sea turtles, Caretta caretta, is still poorly known. Here, we describe the helminth-component community of healthy, free-ranging juvenile loggerhead sea turtles captured in the waters around Madeira Island, Portugal. Fifty-seven were used in this study. The esophagus, stomach, intestine, liver, gallbladder, spleen, kidneys, trachea, bronchi, urinary bladder, heart, left and right aortas, and coelomic cavity were macroscopically inspected; organs and tissues were removed and washed through a sieve. A search for parasites was made using a stereoscopic microscope; recovered parasites were fixed and stored in 70% alcohol until staining and identification. Prevalence, mean intensity, and mean abundance values were recorded. In total, 156 parasite specimens belonging to 9 species were found: nematodes included Anisakis simplex s.l. (larvae) and an unidentified species; digenetic trematodes present were Enodiotrema megachondrus, Rhytidodes gelatinosus, Pyelosomum renicapite, and Calycodes anthos; acanthocephalans included Bolbosoma vasculosum and Rhadinorhynchus pristis; a single cestode, Nybelinia sp., was present. Parasite infections were found to have both low prevalences and intensities. Possible reasons for this include the oligotrophic conditions of the pelagic habitat around Madeira; a 'dilution effect' because of the vastness of the area; and the small size, and thus ingestion rate, of the turtles. Results are discussed in terms of the various turtle populations that may use the waters surrounding Madeira. This work provides valuable information on the parasite fauna of a poorly known stage in the life of loggerhead sea turtles, thereby filling a fundamental gap with regard to features of the parasite fauna in this species.

Report of Enodiotrema megachondrus (Looss, 1899) Looss, 1901 (Digenea: Plagiorchiidae) in a green turtle Chelonia mydas Linnaeus, 1758 (Testudines, Cheloniidae) from Brazil

“…This hypothesis is supported by the observation that the largest parasitological indices (prevalence, mean abundance and mean intensity) were found in turtles with small CCL during the study. A similar fact has been observed by other authors in the same host in the Mediterranean Sea (Aznar et al, 1998), the Madeira archipelago (Valente et al, 2009) and the Adriatic Sea (Gracan et al, 2012).…”

“…Enodiotrema megachondrus is a generalist parasite described in C. mydas (Looss, 1902;Greiner, 2013; presente report), C. caretta (Braun, 1901;Looss, 1901Looss, , 1902Sey, 1977;Aznar et al, 1998;Manfredi et al, 1998;Valente et al, 2009;Santoro et al, 2010;Gracan et al, 2012;Greiner, 2013), Eretmochelys imbricata Linnaeus, 1766 (Groschaft et al, 1977), Lepidochelys olivacea (Eschscholtz, 1829) (Vivaldo et al, 2006;Santoro & Morales, 2007) and Lepidochelys kempii (Garman, 1880) (Greiner, 2013) in different regions of the world. Although E. megachondrus has been described in different hosts, this species has been studied better in C. caretta hosts, especially in regions of Europe (Aznar et al, 1998;Manfredi et al, 1998;Valente et al, 2009;Santoro et al, 2010;Gracan et al, 1012). The analysis of 54 individuals of C. caretta (CCL range: 34 to 69 cm) from Spain revealed a prevalence of 96 % (54/56) and mean intensity of 74.5 (range: 1 to 680) (Aznar et al, 1998).…”

“…2F). Previous records: In C. caretta from Egypt (Braun, 1901;Looss, 1899); France (Euzet & Combes, 1962); Italy (Manfredi et al, 1998); Mediterranean (Aznar et al, 1998;Santoro et al, 2010); Madera (Valente et al, 2009), Adriatic sea (Gracan et al, 2012) and USA (Greiner, 2013); C. mydas from Egypt (Looss, 1902), USA (Greiner, 2013) and Brazil (Present report); E. imbricata from Cuba (Groschaft et al, 1977); L. olivacea from Mexico (Pérez-Ponce de León et al, 1996;Vivaldo et al, 2006) and Costa Rica (Santoro & Morales, 2007) and L. kempii from and USA (Greiner, 2013).…”

“…Santoro et al (2010) studied the parasite composition in 182 individuals of C. caretta from six locations in the central western region of the Mediterranean Sea and found that E. megachondrus was the most frequent parasite, with prevalence rates ranging from 25.0 % to 96.3 % as well as mean intensity ranging from 3.0 to 131.4 (see table 2 by Santoro et al, 2010). In the archipelago of Madeira, Valente et al (2009) performed a parasitological analysis of 57 individuals of C. caretta (CCL range: 15.3 to 61.5 cm) and the presence of E. megachondrus was found in 24.6 % of the hosts, accounting for the second most prevalent parasite, with mean intensity of 7.71 (range: 1 to 31). Analyzing 70 individuals of C. caretta from the Adriatic Sea [mean CCL: 45.0 ± 13.6 cm (range: 25.0 to 85.4 cm)], Gracan et al (2012) found a prevalence rate of 4.3 % (3/70) (confi dence interval: 1.2 to 11.9) and mean intensity of 11.3 (confi dence interval: 11.0 to 11.7).…”

Endohelminth parasites of the blacktail comber Serranus atricauda (Pisces: Serranidae), from Madeira Archipelago (Atlantic Ocean)

“…Some genetic studies, using mitochondrial DNA, and parasitological surveys of fish and sea turtles collected in the North Atlantic suggested the existence of a link between the Gulf of Mexico and Madeira Archipelago, due to the influence of the Gulf Stream (Sedberry et al 1996, Bolten et al 1998, Valente et al 2009, and another link with the Mediterranean (Gibson & Costa 1997). Furthermore, genetic studies using cytochrome b have demonstrated that serranids present in the eastern Atlantic are closely related to the New World species (Maggio et al 2005).…”