Effects of Parasite Infection and Host Body Size on Habitat Associations of Invasive Aquatic Snails: Implications for Environmental Monitoring

Abstract

The Comal River, a spring-fed system in central Texas, was invaded in the 1960s by two Asian aquatic snails (Thiaridae: red-rimmed melania Melanoides tuberculata and quilted melania Tarebia granifera) and subsequently by three of their trematode parasites (the avian eye-fluke Philophthalmus gralli in the 1960s; the gill trematode Centrocestus formosanus in the 1990s; and the intestinal fluke Haplorchis pumilio in the 2000s). Previous snail collections (2001)(2002) established that habitat conditions significantly affect the distribution of both snail species. However, the effects of snail size (known to influence infection prevalence) and habitat conditions (known to influence snail size) on trematode infection patterns in this system were not evaluated. In a re-evaluation of this data set, logistic regression analyses with individual snails showed that for both M. tuberculata and T. granifera populations, large snails were more likely to be infected than small snails, and habitat conditions were significantly related to infection in T. granifera. However, only snail size was significant in explaining the probability of infection in M. tuberculata. This result was confirmed by linear regression models, which showed that both infected and noninfected M. tuberculata used similar habitats, as large individuals in both infection categories were found in patches dominated by fine substrates and high levels of aquatic vegetation and detritus. For the large size-class of T. granifera, noninfected individuals were found primarily in habitats with silt/sand substrates and high vegetation and detritus cover, while infected individuals occurred among all available habitats. Using these results, we suggest that targeted sampling of large individuals of M. tuberculata in habitats with high detritus and vegetation and large individuals of T. granifera in any habitat can be used to efficiently ascertain parasite "hot spots" and to evaluate changes in parasite prevalence or detect the invasion of new parasites in these thiarid snails.

Diagnosis of Centrocestus formosanus Infection in Zebrafish (Danio rerio) in Italy: A Window to a New Globalization-Derived Invasive Microorganism

“…The causes of C. formosanus global spread are still subject to debate. Some authors pointed at the dissemination (deliberate or accidental) of its first intermediate host, Melanoides tuberculata, whereas others hold responsible the movements of birds and freshwater fish [16,17,19,21,25,27,28,30,[49][50][51]. In particular, given the huge numbers of the ornamental fish industry in Europe (approximately 300 million fish, more than 2500 species, of which 60% are of freshwater origin), the importation of ornamental freshwater fish, from countries where C. formosanus is endemic, plays a crucial role in spreading this parasite [35,36,51].…”

“…The current report draws the attention on C. formosanus as an invasive parasite, as well as on other species that could be similarly introduced in Europe, underlining the need for epidemiological studies and appropriate preventive and control programs, in order to monitor their occurrence and prevent their negative consequences for economy, biodiversity, scientific research, animal and public health [6,17,19,20,22,23,[28][29][30]47,48]. Some aspects of biology and epidemiology, regarding both animal and human hosts, should be further explored in Europe [7,17,20,26,47,49]. Teams of experts in "one health" control should be the first actors involved in applying good management and efficient measures, especially during the intentional movement of animals, such as border inspection, accompanying health certification, quarantine measures, and, if necessary, treatment (prior to export or upon arrival) and disinfection procedures [19,22,29,48].…”

“…Teams of experts in "one health" control should be the first actors involved in applying good management and efficient measures, especially during the intentional movement of animals, such as border inspection, accompanying health certification, quarantine measures, and, if necessary, treatment (prior to export or upon arrival) and disinfection procedures [19,22,29,48]. Additionally, adequate strategies should be applied in aquaculture facilities, including training of traders and farmers, regular examination of farmed fish, elimination of snail populations, avoidance of dispersal of farmed fish, and prevention of access to other species, especially birds and mammals [10,[17][18][19]21,22,49]. Specific recommendations concerning diseases in ornamental fish should be strictly followed and the mobilization of these animals should be better considered on the basis of good practices and proper diagnosis of these potential pathogens [52].…”

Freshwater disease hotspots: Drivers of fine‐scale spatial heterogeneity in trematode parasitism in streams

“…Focusing on trematode parasites in Juga snails, we were particularly interested in the combined roles of environmental and host‐related factors on individual‐level infection status and spatial patterns in trematode density. We focused on four environmental factors (allochthonous materials, stream depth, flow velocity, and substrate rugosity) that we expected to indirectly influence trematode density through effects on snail size, density, and/or habitat use (Diamond, 1982; Johnson & Brown, 1997; Stewart & Garcia, 2002; Tolley‐Jordan & Chadwick, 2019). We expected size and density of snails to be positively associated with stream depth and allochthonous materials and negatively associated with stream flow velocity and substrate rugosity (Diamond, 1982; Johnson & Brown, 1997; Ross & Ultsch, 1980).…”

Evolución De Las Entidades Angiostrongilosis Y Fasciolosis Durante Los Años 2015 Y 2016 en La Provincia Villa Clara, Cuba

“…Neotropical Helminthology, 2020, 14(1), ene-jun diversidad y conservación (Iannacone & Alvariño, 2002;Martínez, 2003, Iannacone et al, 2013Cai et al, 2018;Tolley-Jordan & Chadwick, 2018;Argota et al, 2019), así como controladores biológicos de otras especies de moluscos implicadas en la transmisión de enfermedades (Rondelaud et al, 2004;Anónimo, 2007;Alarcón et al, 2010). Sin embargo, el mayor interés de los moluscos fluviales desde el punto de vista médico veterinario, radica en que sirven como hospederos intermediarios a varias parasitosis, ya que pueden cerrar el ciclo vital de éstos parásitos, dentro de las que resaltan: la fasciolosis, angiostrongilosis, paramfistomosis y esquistosomosis (Rondelaud et al, 2004;Faltýnková et al, 2008;Vázquez & Sánchez, 2015).…”