Rina Ramírez

The Introduction of Nonnative Fishes into Freshwater Systems of Peru

Since the 1930s, alien fishes (fishes not native to Peru) have been introduced into the freshwater systems of Peru for different purposes such as fish farming, the ornamental fish trade, public health applications, and sport fishing. The fish were introduced either deliberately or casually into the three hydrographic systems of the country (Amazon, Pacific coastal rivers, and Lake Titicaca). To date, 20 alien species have been found in the continental water systems of Peru: Aristichythys nobilis, Carassius auratus, Cichlasoma nigrofasciatum, Ctenopharyngodon idella, Cyprinus carpio, Gambusia cf. affinis, Hypophthalmichthys molitrix, Odonthestes bonariensis, Oncorhynchus mykiss, Oreochromis aureus, Oreochromis hornorum, Oreochromis mossambicus, Oreochromis niloticus, Oreochromis urolepis, Poecilia reticulata, Poecilia velifera, Tilapia rendalli, Trichogaster leerii, Xiphophorus helleri, and Xiphophorus maculatus. Nativespecies transfers have also occurred; seven Peruvian species have been transferred from lowland forest waters to water systems of both the highland forest and the coast (reservoirs): Arapaima gigas, Astronotus ocellatus, Brycon cephalus, Cichla monoculus, Colossoma macropomum, Piaractus brachypomus, and Prochilodus nigricans. Herein, we present an overview of the current situation of these species introductions and transfers in Peru based on both fieldwork and a review of the pertinent literature. We then focus on the three alien species most frequently found in natural environments but not previously evaluated for their impacts. Our surveys in the aquatic basins of the Parque Nacional Rı́o Abiseo (PNRA; high-altitude, Amazon River system) show that the alien Oncorhynchus mykiss (rainbow trout) is the dominant species and that the three native species usually common in Peruvian highland Andean river basins (Astroblepus spp.) are present only in low numbers. The other two alien species— Oreochromis niloticus (tilapia) and Poecilia reticulata (guppy)—are well established and widely distributed in both the Huallaga (highland forest, Amazon River system)

Re-characterization of the Red-lip Megalobulimus (Gastropoda: Strophocheilidae) from Peru with description of a new species

Megalobulimus K. Miller, 1878 is a genus of land snails that includes the largest living snails in the Neotropics. The main goal of this paper was to review all species of Megalobulimus that have a red lip, and which are distributed in Peru. We carried out a detailed description of their shells and soft parts, and conducted a multivariate analysis on their shells and geographic distribution. There are two species reported from Peru, Megalobulimus capillaceus (Pfeiffer, 1855) and Megalobulimus separabilis (Fulton, 1903). Megalobulimus capillaceus is known to occur in three regions - San Martin, Huanuco and Cusco - but the Cusco population is undoubtedly different from all remaining populations, and is recognized herein as a new species, Megalobulimus florezi sp. nov. This species has a more elongated shell, penis club-shaped, epiphallus longer, and free oviduct longer than M. capillaceus. By contrast, the male genitalia of M. separabilis is filiform and does not present an external diverticulum in the free oviduct.

Molecular identification of iron oxidizing bacteria isolated from acid mine drainages in Peru

Acidophilic iron-oxidizing microorganisms are important in both environmental and biotechnological applications. These microorganisms are known to accelerate the dissolution of sulfur minerals such as pyrite (FeS2), leading to the acid mine drainage generation , a serious pollution problem, that makes these microorganisms essential to the commercial processing of minerals and sulfur. In order to answer this question, diversity of native acidophilic bacteria isolated from acid mine drainage of Peru was evaluated. The samples were collected from Yanacocha mining (3000 m.a.s.l.) located in the North of Cajamarca region, Yanamina mining (4440 m.a.s.l.) located in the middle of Huancavelica region; finally, SPCC mining (2000 m.a.s.l.) located in the South of Moquegua region. We isolated 11 strains from which three were identified as Acidithiobacillus ferrooxidans, two as At. ferrivorans, two as At. ferridurans, three as Leptospirillum ferrooxidans and one as Acidiphilium sp. by comparative sequencing of PCR-amplified 16S rRNA genes. Phylogenetic analysis of the 16S rRNA genes revealed that some of the strains isolated are closely related to other already known, but there are some with similarities lower than < 95 percent. Our results provide the first study on the diversity of iron-oxidizing bacteria isolated from acid mine drainage of Peru.

Molecular evidence for the polyphyly of Bostryx (Gastropoda: Bulimulidae) and genetic diversity of Bostryx aguilari

Bostryx is largely distributed in Andean Valleys and Lomas formations along the coast of Peru and Chile. One species, Bostryx aguilari, is restricted to Lomas formations located in the Department of Lima (Peru). The use of genetic information has become essential in phylogenetic and population studies with conservation purposes. Considering the rapid degradation of desert ecosystems, which threatens the survival of vulnerable species, the aim of this study was, first, to resolve evolutionary relationships within Bostryx and to determine the position of Bostryx within the Bulimulidae, and second, to survey the genetic diversity of Bostryx aguilari, a species considered rare. Sequences of the mitochondrial 16S rRNA and nuclear rRNA regions were obtained for 12 and 11 species of Bulimulidae, respectively, including seven species of Bostryx. Sequences of the 16S rRNA gene were obtained for 14 individuals (from four different populations) of Bostryx aguilari. Phylogenetic reconstructions were carried out using Neighbor-Joining, Maximum Parsimony, Maximum Likelihood and Bayesian Inference methods. The monophyly of Bostryx was not supported. In our results, B. solutus (type species of Bostryx) grouped only with B. aguilari, B. conspersus, B. modestus, B. scalariformis and B. sordidus, forming a monophyletic group that is strongly supported in all analyses. In case the taxonomy of Bostryx is reviewed in the future, this group should keep the generic name. Bostryx aguilari was found to have both low genetic diversity and small population size. We recommend that conservation efforts should be increased in Lomas ecosystems to ensure the survival of B. aguilari, and a large number of other rare species restricted to Lomas.

The Genus Megalobulimus (Gastropoda: Strophocheilidae) from Peruvian Andes: Re-Description of Megalobulimus leucostoma and Description of Two New Species

Abstract: A major taxonomic problem around the genus Megalobulimus Miller,1878, the largest land snails in the Neotropics, is plasticity of conchological characters. Here we re-describe Megalobulimus leucostoma (Sowerby, 1835) and describe two new species of Megalobulimus from Southern Peru, Megalobulimus tayacajus sp.nov. and Megalobulimus inambarisense sp.nov. These descriptions are based on both conchological and soft anatomical characters. Megalobulimus leucostoma is characterized by the presence of a retractor muscle with two insertions to the buccal mass, two small bulges on pre-rectal valve, and a geographical distribution appears limited to Cusco. Megalobulimus tayacajus sp.nov. is characterized by the presence of a retractor muscle that divides near the buccal mass, two lobed bulges on pre-rectal valve, and to date, has been found only in Huancavelica. Megalobulimus inambarisense sp.nov. is characterized by the presence of a retractor muscle with one insertion to the buccal mass, two big bulges on pre-rectal valve, and a distribution appears limited to Puno. The digestive system appears to serve as useful characters to discriminate these species and, when combined with shell and reproductive characters, may help to understand better the evolution and ecology of these snails.