Tag Archives: ecuador

A misidentified prey

In 2002 R. Williams published a brief note on a bird, the Scaled Fruiteater Ampeliodes tschudii, which had been observed near Tandayapa in Ecuador with a snail in its beak.

 

According to information given to him by a third person, only two species of terrestrial snail were living in that area: “the arboreal Plekocheilus sp. and a large terrestrial form in the family Pleurodontidae [now Labyrinthidae]”. Mr. Williams concluded that it must have been the Plekocheilus species that was caught by the bird.

Apart from the obvious errors in the sentence quoted above (both snails are terrestrial, and Plekocheilus species are not truly arboreal), it is clear from the picture provided in the note and copied above that the prey was misidentified. The shell in the bird’s beak look definitely like a Drymaeus species and the most likely candidate is Drymaeus aequatorianus (E.A. Smith, 1877) which is known from that region.

Reference:
Williams, R.S.R., 2002. Consumption of arboreal snails by Scaled Fruiteater Ampeliodes tschudii. – Cotinga, 18: 100.

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What does a Pacman eat?

Under this intriguing title a paper appeared that highlights the food of an Ecuadorian frog.

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“We describe for the first time the feeding ecology of the Pacific horned frog (Ceratophrys stolzmanni), as inferred through gastrointestinal tract content analysis and behavioural observations in its natural habitat. Ingested prey in adults ranged from mites and various insects to frogs and snakes. Prey items predominantly consisted of gastropods, non-formicid hymenopterans, and centipedes. We found no relationship between the size of the predator and the prey ingested, in terms of prey size, volume or number of items ingested. Additional direct observations indicate that all post-metamorphic stages are voracious, preying on vertebrates and engaging in anurophagy, cannibalism, and even necrophagy. Our study sheds light on the feeding habits of one of the least known species of horned frog”.

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Gastropods have not been specified in the paper, so we have to guess about which species it concerns and if they are really all belong to Pulmonata or also to other groups. The observations were made in the Arenillas nature reserve in El Oro province.

Reference:
Székely, D., Gaona, F.P., Székely, P., Cogălniceanu D., 2019. What does a Pacman eat? Macrophagy and necrophagy in a generalist predator (Ceratophrys stolzmanni). – PeerJ7e6406.

Achatina in Ecuador

Earlier this year a paper by Cuasapaz-Sarabia & Salas presented results about the occurrence of Achatina fulica in a private nature reserve. “Achatina fulica is an invasive terrestrial gastropod known as one of the 100 most harmful invasive species in the world. Achatina fulica is known in Ecuador since 2008, but the impact over their native ecosystems has not evaluated. The main objective was to determine the home range (HR) of this species in two zones with different levels of intervention in the Cerro Blanco reserve. The field work consisted in the capture, marking, recapture, taking of morphometric measurements and georeferencing of the individuals; for the analysis of data, HR was calculated using the convex polygon method, and environmental variables were correlated through a principal component analysis (PCA). The average HR in the altered zone was 3.58 m2 (± 0.93, n = 30), and on the ecotourist trail was 3.27 m2 (± 0.48, n = 40); the humidity was the environmental parameter that directly influences the life area and the population density in both zones study. The management of this invasive species does not appear as a key management issue for this private reserve, so it is recommended a control actions for its eradication“.

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It is remarkable that – although the occurrence of this species in Ecuador is known for more than 10 years – eradication programs seem to be lagging behind. And even (private) nature reserves are not alarmed about it. Thus the risk of spread of this important pest species is still prevalent. A serious issue…

Reference:
Cuasapaz-Sarabia, J. & Salas, J.A., 2019. Área de vida de la especie invasora Achatina fulica (Gastropoda: Achatinidae) en un área de conservación de bosque seco ecuatoriano. Revista peruana de biología 26(1): 41 – 48.

Galápagos Gastrocopta

A recent paper by Miquel & Brito focusses on Gastrocopta species from the Galápagos, already mentioned in a previous paper.
Their abstract is as follows “A revision of Gastrocopta from the Galápagos Islands (Ecuador) is made. Four new species from Pinzón, Santa Cruz and Floreana Islands are described; species previously known are redescribed and new locations are added. Gastrocopta (Gastrocopta) reibischi is revalidated through new records from Floreana, Isabela and San Bartolomé Islands. Shell shape and the number, morphology and disposition of the apertural barriers support the discrimination of the taxa. The species have cylindrical to pupoid shells; the number of apertural barriers –differentiated as lamellae, folds and nodulae – varies between 4 and 11, almost completely occluding the aperture in the more complex cases. These structures are: angular-parietal, infraparietal, supracolumellar, columellar, subcolumellar lamellae, and supernumerary, basal, infrapalatal, lower-palatal, interpalatal, upper-palatal and suprapalatal folds. In addition to this classic scheme, a supernumerary fold and a nodule are added. Calcareous concretions –pustulae – are found in several species, mainly located in the peristome. The aulacognathous jaw and radular dentition formulae of Gastrocopta (Gastrocopta) clausa and Gastrocopta (Gastrocopta) munita, are described and photographed for the first time“.

The new species are all belonging to the nominate subgenus, and have been named respectively G. (G.) aliciae, G. (G.) christinae, G. (G.) franki, and G. (G.) herrerai. This means that the number of Gastrocoptid species from this archipelago has doubled! As most research on this group so far has been limited to a few islands, further novelties are to be expected as a result of future work.

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Reference:
Miquel, S.E. & Brito, F.F., 2019. Taxonomy and distribution of species of Gastrocopta Wollaston 1878 (Mollusca: Gastropoda: Gastrocoptidae) from the Galápagos Islands (Ecuador). – Molluscan Research, 39: 265-279.

Naesiotus in ethnological use

Recently a paper on the use and economic value of the snail Naesiotus quitensis was published in a not-so-common journal (at least for shell enthusiasts).

The abstract reads: “The terrestrial mollusks in Ecuador present a high abundance of endemic species with different categories of commercial and gastronomical uses. In this context, this study proposes documenting the value and current economic use given to the mollusk Naesiotus quitensis, in the Sangolqui population on the market “The Tourism”, based on semi-structured interviews performed on 20 persons in November 2017. As a result of the interviews it was shown that the origin of the eatable snails is Otavalo city, located in the Imbabura province, in the northern of the country. This information has been made evident in studies that point out that the climate diversification in the mountain range of the Andes allow to have a great variety of mollusks variety in these regions. Due to this abundance people collect the mollusks in their natural habitat (“helicicolecta”) for use as a commercial and economic good; in regard to the economic value, a major consumption was reported for the presentation of this mollusk cooked with lemon, in small bags. In the categorical approach of use, two new categories were registered: the ritualist which refers to delivering it as an offering in cemeteries and the playful one that is carried out as games between underage children of the sector. With these results we conclude that in spite of the parish of Sangolqui being a place that still preserves these traditions, the traditional heritage of consumption of this mollusk from the elderly towards the next generations is not evidenced. This might be due to little investigation and welcoming of this species of terrestrial snail in people of all ages; for this reason, it is difficult to know if there is an irrational exploitation of this species”.

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During my last visit to Ecuador I had seen the use of these snails as a snack food, but didn’t encounter the other uses. Although it interesting stuff for an ethnographer, I remain with what I have said before her: do not eat snails…

Reference:
Gutiérrez Cantuña, E.B. & Guainilla Maldonado, W.R. 2018. Uso y valor económico de Naesiotus quitensis (Pfeiffer, 1848) (Mollusca: Bulimulidae) como alimento tradicional en la parroquia urbana Sangolqui, Cantón Rumiñahui, Ecuador. – Ethnoscientia, 3: 1–6.

Invasive apple snails

This time not a terrestrial but a freshwater topic: apple snails, or the family Ampullariidae.
Joshi et al. have just published a book on the biology and management of invasive species of this group. The book contains 22 chapters, divided into three themes: General aspects of apple snail biology, Country specific reports, and Management and use.

In the second section two chapters deal with Pomacea canaliculata respectively in Argentina and Ecuador.

The Argentinan chapter is written by P.R. Martin et al., the abstract reads “Pomacea canaliculata is in many respects the best known species of apple snails (family Ampullariidae), although the available information is both fragmentary and geographically biased. Most studies in its non-native range have focused on applied aspects in managed or arti cial wetlands in various countries in Southeast Asia. In its natural range the emphasis has been on basic studies of its reproductive biology, ecology and behaviour in populations from small streams at the southernmost extreme of its distribution (Southern Pampas, Argentina). The extreme geographic position and the lotic nature of these populations may have biased some conclusions about the behavioural and ecological traits of P. canaliculata; contemporary evolution and genetic exchange may also have diversi ed these traits in the non-native range. Even though the ecological information from native populations may not be directly applicable elsewhere, it nevertheless remains as a necessary reference to understand the full potential of adaptation and spread of P. canaliculata to new environments around the world. Surprisingly enough, comparative studies of native and non-native populations of Pomacea spp. are almost lacking. This short review focuses on the distribution, thermal biology, aerial respiration, feeding, reproduction, phenotypic plasticity and shell shape of Pomacea canaliculata in its native range in Argentina.

The Ecuadorian chapter is M. Correoso et al.; the abstract is “This article characterises and analyses the presence of the alien invasive species Pomacea canaliculata in Ecuador, a pest present in many countries that has severe impacts on agriculture, human health and the natural environment. For the rst time, a list of the native species of the genus Pomacea in Ecuador is provided, as well as an occurrence map, based on review of existing (but few) bibliographic data, museum collections and recent eld work. There is a lack of information on other mollusc species in Ecuador, but there is the potential for ecological impact of P. canaliculata on the native mollusc fauna, especially other Pomacea species, which may already be in decline. Other biological threats and consequences are considered, highlighting the impacts that the invasion has had in this Andean country. Also, events that have occurred since the detection of the pest are reviewed, in particular, the decisions adopted by the rice agricultural sector in comparison with those reported by other countries facing a similar situation. The epidemiological role of P. canaliculata in Ecuador is analysed following confirmation that P. canaliculata can carry the nematode Angiostrongylus cantonensis, which causes eosinophilic meningitis. Cases of human infection and the possible routes of transmission are discussed, confirming that Ecuador was the first South American country to have cases of the disease. These results are compared with those for the giant African snail (Lissachatina fulica), a mollusc that can also transmit the disease. It is probable that native Pomacea species can also be infected with the nematode. Finally, a wide range of measures and management actions that should be considered, and possibly adopted, by Ecuador are proposed with the goal of controlling this dangerous pest.

Reference:
Joshi, R.C., Cowie, R.H. & Sebastian, L.S., 2017. Biology and management of invasive apple snails. Muõz: Philippine Rice Research Institute, 406 pp. Available at http://tinyurl.com/y8aw4htb