Hirudinida: Glossiphoniidae) on the European Pond Turtle (Emys Orbicularis) in Northeast Algeria
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Herpetology Notes, volume 10: 3-8 (2017) (published online on 27 January 2017) Prevalence of Placobdella costata (Fr. Mûller, 1846) (Hirudinida: Glossiphoniidae) on the European pond turtle (Emys orbicularis) in northeast Algeria Samira Fediras1, Rachid Rouag2,*, Nadia Ziane1, Anthony Olivier3, Arnaud Béchet3 and Slim Benyacoub1 Abstract. In Algeria, Emydidae is represented by only one species, the European pond turtle Emys orbicularis (Linnaeus, 1758). A population was studied in the spring of 2013 in the El Kala National Parc. The objective of this study was to identify and quantify the number of leech species. Placobdella costata (Fr. Mûller, 1846) (Hirudinida: Glossiphoniidae) proved to be the only leech species of that was parasite of this Emys orbicularis population. Its prevalence was 50.9%, which was very low at the juvenile stage (14.2%). The intensity (average number of leeches per turtle) was 0.51± 1.20 for this population, but it was lower at the juvenile stage (0.14 ± 0.37). No relationship exists between the parasitic load and the morphological parameters. However, posterior part (hind limbs) had the highest parasite load (57.14 %). Keywords: Emys orbicularis, Glossiphoniidae, Placobdella costata, prevalence, parasite, Algeria Introduction can significantly alter host population demography (Iglesias et al., 2015; Meyer et al., 2015), and are critical The European pond turtle (Emys orbicularis) occurs to study in evolutionary and ecological contexts (Tyre over an extensive distribution range. It’s found from et al., 2003). In this paper, we identify and analyze the Portugal to Aral Sea (Kazakhstan), from northern prevalence of the leeches in an Algerian population of Germany and Moscow province (Russia) to southern Emys orbicularis, which constitutes the first study on Italy, Sicily and northern Africa and south-eastwards this subject for Algeria. from Turkey to the eastern Caucasus Republics and the southern shore of the Caspian Sea (Fritz, 1998; Materials and Methods Fritz, 2003). The European pond turtle is considered to be endangered in many parts of its range (Fritz and Our study was conducted from March to August Andreas, 2000). Intensification of agriculture and water 2013 on a 5 ha area situated innorthern part of the Lake management, as well as the loss of suitable habitat Tonga, which is situated in the northeastern of Algeria are the major threats facing this species. However, between 36°43’N and 36°57’N and between 07°43’E the species is protected in many European countries and 08°37’E. The climate there is Mediterranean, with (e.g., Schneeweiss, 1998; Zuffi and Ballasina, 1998; most of the annual rainfall (630 mm) falling during the Mitrus, 2005). Despite its wide distribution, little is winter months. The lake is about 2700 ha in area, and as known about the potential role of leeches as vectors of a shallow water body with rich vegetation, it represents parasites that could affect E. orbicularis, yet, parasites one of the most important freshwater wetlands in northeastern Algeria (De Belair, 1990). Vegetation beds composed of emergent and floating-leaved plants are very extensive. The emergent vegetation of Lake Tonga is dominated by the common reed (Phragmites australis 1 Université Badji Mokhtar. Département de Biologie. BP. 12. Cav.) and the lesser reed mace (Typha angustifolia L.). El Hadjar. 23000 Annaba, Algeria. The submerged and surface-floating vegetation of this 2 Université Chadli Bendjedid. 36100 El Tarf, Algeria. 3 Institut de recherche de la Tour du Valat, Le Sambuc, 13200 lake is dominated by the white water-lily (Nymphea alba Arles, France. L.) and pondweeds (Potamogeton lucens L.) (Bakaria et * Corresponding author e-mail: mailto: [email protected] al., 2009). 4 Samira Fediras et al. During the study, 53 European pond turtles caught by hand were marked by notching, the marginal scutes (Cagle 1939; Servan et al. 1986). Individual variables were measured on every specimen caught such as, weight, size and age. Age determination of each captured tortoise was done by growth annuli counts on the shell, one growth annulus being added each year (Castanet and Cheylan, 1979; Castanet, 1988; Germano and Bury, 1998). Carapace length was measured using a digital calliper (precision ±0.1 mm) with the same measurement criteria as Stubbs and Swingland (1984). The weight of the turtles was measured using a digital balance (precision ±1 g). Sex was determined by secondary sexual characteristics (e.g., plastral Figure 1. A- dorsal view of P. costata, B- ventral view of P. concavity, tail length) (Servan, 1988). Turtles less than costata (Photos by Fediras S.). 12 cm long were considered too small for sexing and were classified as juveniles. Leeches were collected manually and placed in individual vials (labelled by turtle code) in 70% EtOH southeast as the southern Arabian Peninsula (Nesemann until further examination was possible. All turtles were and Neubert, 1999; Bielecki et al., 2012). released immediately at the point of capture. Leeches Leeches differed in age and ranged in size from about were counted and identified to species level in the two mm for the young to two centimeters for adults. The laboratory using the taxonomic keys for Hirudinea in studied turtles consisted of 25 females, 21 males and 7 Tunisia (Ben Ahmed et al., 2008). Leech prevalence juveniles. Of the 53 turtles examined, 27 (50.9%) were (%) and intensity and standard deviation (mean ± sd) infested by leeches: 42.8% of the males, 68% of the were also calculated (Margolis et al., 1982). Attachment females, and 14.2% juveniles were parasitized (Table sites were recorded only on 14 turtles. Correlation 1). data, leech and turtle infestation were calculated using the coefficient (r), and a t-test was used to analyze differences between genders and ages; differences were considered statistically significant when P ≤ 0.05. Table 1.Prevalence and intensity of infestation. Statistical analysis of the morphological parameters Table 1. Prevalence and intensity of infestation. was carried out using the Excel software and Minitab® Leech Prevalence Intensity Turtle data 15.1.30.0. % ∑ Mean ± Sd Range Males (n = 21) 42.8 9 0.42 ± 0.99 0–3 Results Females (n = 25) 68.0 17 0.68 ± 1.27 0–7 Juveniles (n = 7) 14.2 1 0.14 ± 0.37 0–1 A total of 27 leeches were collected and identified Total (n= 53) 50.9 27 0.51 ± 1.20 0–7 as Placobdella costata (Fr. Mûller, 1846) (Hirudinida: Glossiphoniidae) (Fig. 1). Glossiphoniidae is one of the most species rich leech families in terms of the number of species described (Ringuelet, 1985; Sawyer, 1986). Table 2.Prevalence on attachment sites on turtles The group is comprised principally of dorsoventrally The mean intensity is of 0.51 ± 1.20 leeches/turtle flattened leeches normally found feeding on the blood leeches (rangeAttachment 0–7 leeches). sites Turtle It was(N=14) higher in females than in of turtles or amphibians. Although some species, like males with respective values of 0.68∑ Mean ± 1.27 ± SD and (Range) 0.42 ± those in the genera Helobdella Blanchard, 1896 and 0.99,Hind and limbs very low among8 juveniles8 with0.57 ± a 0.51 value (0–1) of 0.14 Glossiphonia Johnson, 1816, feed on the haemolymph ± 0.37.Tail Males and females0 did not0 0differ significantly of aquatic oligochaetes and snails (Siddall et al., 2005). in parasiteHead load with (t-value1 = -1 0.7;0.07 p-value ± 0.26 (0–1) = 0.491; Placobdella costata is usually considered to be a df = Forelimbs37 at t-test), and there1 was 1no 0.07difference ± 0.26 (0–1) between Mediterranean species that has spread over large parts adultsCarapace and juveniles (t-value4 = 1.79;5 0.35 p-value ± 0.63 (0–2) = 0.083; of Central and Eastern Europe, reaching as far to the df = 32).Plastron 4 12 0.85 ± 1.92 (0–7) Table 3. Relation between parasite load and biometric parameters (Number of turtles=53) Age (years) Carapace length (mm) Plastron length (mm) Body weight r = -0.293 r = -0.008 r = 0.047 r = 0.171 Number of leeches (p= 0.175) (p= 0.972) (p= 0.830) (p= 0.222) Prevalence of Placobdella costata on the European pond turtle in northeast Algeria 5 Data show that the hind limbs are the most common attachment site with a prevalence of 57.14% (8/14). The head and forelimbs with 7.14% (1/14) have the lowest infection. We observed 28.57% (4/14) of the leeches were both on the plastron and on the carapace (Fig. 2). The plastron and the hind limbs of the turtles had the highestTable parasite 1.Prevalence load with0.85 and intensity ± 1.92 of infestation. leeches for the plastron, 0.57 ± 0.51 for the hind limbs. The forelimbs and the head wereLeech loaded Prevalence with 0.07 ± 0.26Intensity leeches. No Turtle data parasites were found on% the tail ∑(Table Mean 2).± Sd The Range turtle withMales the (mostn = 21) parasites 42.8 was a female9 with0.42 ± 7 0.99 leeches. 0–3 The posteriorFemales (partn = 25) of the turtle68.0 (hind limbs)17 0.68 seems ± 1.27 to 0–7be the Figure 2. Attachment of Placobdella costata on Emys orbicularis. mostJuveniles vulnerable (n = 7) area and14.2 the head1 and0.14 fore ± 0.37 limbs 0–1 were the Totalleast (infestedn= 53) parts.50.9 27 0.51 ± 1.20 0–7 Table 2.Prevalence on attachment sites on turtles of Emys orbicularis. This species is known for its Table 2. Prevalence on attachment sites on turtles. haematophagous ectoparasitic feeding on freshwater turtles, in Europe mainly on Emys orbicularis (Nesemann leeches Attachment sites Turtle (N=14) and Neubert, 1999; Vamberger and Trontelj 2007), but ∑ Mean ± SD (Range) it has also been reported on Mauremys leprosa (Romero Hind limbs 8 8 0.57 ± 0.51 (0–1) et al., 2014) and M.