Comparative Mitogenome Analysis of Two Native Apple Snail Species (Ampullariidae, Pomacea) from Peruvian Amazon.

Apple snails of the genus Pomacea Perry, 1810 (Mollusca: Caenogastropoda: Ampullariidae) are native to the Neotropics and exhibit high species diversity, holding cultural and ecological significance as an important protein source in Peru. However, most genetic studies in Pomacea have focused mostly on invasive species, especially in Southeast Asia, where they are considered important pests. In this study, we assembled and annotated the mitochondrial genomes of two Pomacea species native to the Peruvian Amazon: Pomacea reevei Ampuero & Ramírez, 2023 and Pomacea aulanieri (Deville & Hupé, 1850). The mitogenomes of P. reevei and P. aulanieri comprise 15,660 and 16,096 bp, respectively, and contain the typical 37 genes of the animal mitochondria with a large control region of 292 bp in P. reevei and 524 bp in P. aulanieri-which fall within the range of what is currently known in Pomacea. Comparisons with previously published mitogenomes in Pomacea revealed differences in the overlapping of adjacent genes, the size of certain protein-coding genes (PCGs) and the secondary structure of some tRNAs that are consistent with the phylogenetic relationships between these species. These findings provide valuable insights into the systematics and genomics of the genus Pomacea.

Who is Andesiops peruvianus (Ulmer, 1920) (Ephemeroptera: Baetidae)? New insight from the type basin using morphological and molecular analyses.

Andesiops peruvianus (Ulmer, 1920) is a small minnow mayfly with a distribution throughout the Andes Mountains, mainly in lotic environments. In recent years, the taxonomic status of the species has been shifting, even finding out molecular and morphological evidence to consider it as a cryptic species. In this work, we collected seven specimens of A. peruvianus from the Lake Titicaca in Peru, the type locality and perform molecular and morphological analyses to test their relationship with specimens from other regions. The species delimitation analysis revealed the existence of five MOTUs for specimens identified as A. peruvianus along the Andes Mountains, while the Lake Titicaca specimens formed a single MOTU with high interspecific distance. In this MOTU were found specimens with different types of abdominal gills, from translucent to markedly tracheated supporting the hypothesis of phenotypic plasticity at the abdominal gill level. Also, an extension in the range of tarsal claw denticles, from 10-12 to 10-14, were observed, higher than what were found in other regions. Our results support A. peruvianus as a species complex and reveal A. peruvianus from Titicaca as a single MOTU. Future morphological revisions of topotype specimens as well as from other Andean regions are required to strengthen the diagnosis of informative characteristics at both the larval and adult stage to elucidate the real status of the species.

Fishes from Yarinacocha lake: an emblematic Amazonian ecosystem in the lower Ucayali River basin, Pucallpa, Peru / Peixes do lago Yarinacocha: um ecossistema amazônico emblemático na bacia do baixo rio Ucayali, Pucallpa, Peru

The Yarinacocha lake is an emblematic ecosystem of the Peruvian Amazon, representing the main point of fish landing and a tourist attraction in the city of Pucallpa. The wide fauna diversity in this area has made it the target of various studies, although for fish species most of them were focused on commercial species. In this work, we carried out the first ichthyofauna species inventory of the Yarinacocha lake, sampling throughout the entire lake during the rainy and dry seasons and considering also all previously recorded species deposited in the Ichthyological Collection of the MUSM with the same locality. A total of 164 fish species were recorded, representing 10 orders (plus Eupercaria), 34 families and 116 genera. Characiformes was the order with more species (68 spp., 41.5%) followed by Siluriformes (59 spp., 36%), Cichliformes (17 spp., 10.5%), and Gymnotiformes (8 spp., 4.9%). The most highly represented families, including almost 55.5% of the total diversity obtained, were Characidae (23 spp., 14%), followed by Cichlidae (17 spp., 10.4%), Loricariidae (14 spp., 8.5%), Pimelodidae (13 spp., 7.9%), Doradidae (13 spp., 7.4%) and Anostomidae (12 spp., 7.3%). From the total fish species recorded in this study, only 22 are considered protected species following the IUCN criteria and 109 species have commercial importance, including 90 ornamental species (54.8%). Our results contribute to the knowledge of the ichthyofauna of the Yarinacocha lake and can be used as a starting point for its conservation and sustainable management over time.

O lago Yarinacocha é um ecossistema emblemático da Amazônia peruana, representando o principal ponto de desembarque de peixes e também uma atração turística da cidade de Pucallpa. A grande diversidade faunística nesta área a tornou alvo de vários estudos, embora para as espécies de peixes a maioria deles tenha sido focada em espécies comerciais. Neste trabalho, realizamos o primeiro inventário da ictiofauna do lago Yarinacocha, amostrando todo o lago durante as estações chuvosa e seca, e também considerando todas as espécies depositadas na Coleção Ictiológica do MUSM dessa localidade. Um total de 164 espécies de peixes foram registradas, representando 10 ordens (mais Eupercaria), 34 famílias e 116 gêneros. Characiformes foi a ordem com mais espécies (68 espécies, 41,5%), seguida por Siluriformes (59 espécies, 36%), Cichliformes (17 espécies, 10,5%) e Gymnotiformes (8 espécies, 4,9%). As famílias mais representadas, incluindo quase 55,5% da diversidade total obtida, foram Characidae (23 spp., 14%), seguido por Cichlidae (17 spp., 10,4%), Loricariidae (14 spp., 8,5%), Pimelodidae (13 spp., 7,9%), Doradidae (13 spp., 7,4%) e Anostomidae (12 spp., 7,3%). Do total de espécies de peixes registradas neste estudo, apenas 22 são consideradas espécies protegidas seguindo os critérios da IUCN e 109 espécies têm importância comercial, incluindo 90 espécies ornamentais (54,8%). Nossos resultados contribuem para o conhecimento da ictiofauna do lago Yarinacocha e podem ser utilizados como ponto de partida para sua conservação e manejo sustentável ao longo do tempo.

First record of the invasive dwarf surf clam Mulinia lateralis (Say 1822) in the eastern Pacific Ocean

Mulinia lateralis is a native bivalve from the Western Atlantic Ocean, distributed from the Gulf of Saint Lawrence in Canada to Yucatan in Mexico. Based on morphological and genetic data of specimens collected in shrimp farms, in this work, we confirm the presence of M. lateralis in the Gulf of Guayaquil, Ecuador. Presence and its consequences of this invasive bivalve in the region is discussed.

Mulinia lateralis es un bivalvo nativo de las aguas del Océano Atlántico Occidental, distribuido desde el Golfo de Saint Lawrence en Canadá hasta Yucatán en México. En este trabajo, la presencia de M. lateralis es confirmada en el Golfo de Guayaquil, Ecuador, con base en datos morfológicos y genéticos de ejemplares colectados en camaroneras. Se presenta una discusión sobre la presencia y consecuencias de este bivalvo invasor en la región.

Taxonomy of Centropomus Lacépède, 1802 (Perciformes: Centropomidae), with focus on the Atlantic species of the genus.

Centropomus Lacépède, 1802 comprises 13 species of the fishes popularly knows as snooks, distributed in both Atlantic and Pacific coasts of America. Despite several studies on the group, conflicting taxonomic classifications still exist, including overlapping diagnostic characters, rendering species diagnoses extremely difficult. Herein, we review the taxonomy of Centropomus to elucidate species identities, redefine their diagnoses and to assess interspecific relationships based on the examination of 376 specimens. The study included complementary approaches, as analyses of external morphologic characters, linear and geometric morphometrics, and molecular analyses. Forty-nine characters were used for external morphology, 17 discrete plus 32 linear measurements. Shape and size were analyzed through geometric morphometrics of 185 specimens in lateral view. Partial sequences of the gene cytochrome c oxidase I were obtained for 129 specimens representing 11 species. Based on the consistent results retrieved from the morphologic and molecular analyses, we recognized six species of Centropomus from the Atlantic coast (C. ensiferus, C. irae, C. parallelus, C. pectinatus, C. poeyi and C. undecimalis). Centropomus mexicanus is treated as a junior synonym of C. parallelus. Six species from the Pacific coast are also tentatively recognized (C. armatus, C. medius, C. nigrescens, C. robalito, C. unionensis, and C. viridis), however further studies on the Pacific species are still needed. Information on type material, diagnosis, distribution, and taxonomic comments are provided for each species. An identification key to the species of Centropomus is presented.

DNA barcoding in the Southeast Pacific marine realm: Low coverage and geographic representation despite high diversity.

The Southeast Pacific comprises two Large Marine Ecosystems, the Pacific Central-American Coastal and the Humboldt Current System; and is one of the less well known in the tropical subregions in terms of biodiversity. To address this, we compared DNA barcoding repositories with the marine biodiversity species for the Southeast Pacific. We obtained a checklist of marine species in the Southeast Pacific (i.e. Colombia, Ecuador, Chile, and Peru) from the Ocean Biodiversity Information System (OBIS) database and compared it with species available at the Barcoding of Life Data System (BOLD) repository. Of the 5504 species records retrieved from OBIS, 42% of them had at least one registered specimen in BOLD (including specimens around the world); however, only 4.5% of records corresponded to publicly available DNA barcodes including specimens collected from a Southeast Pacific country. The low representation of barcoded species does not vary much across the different taxonomic groups or within countries, but we observed an asymmetric distribution of DNA barcoding records for taxonomic groups along the coast, being more abundant for the Humboldt Current System than the Pacific Central-American Coastal. We observed high-level of barcode records with Barcode Index Number (BIN) incongruences, particularly for fishes (Actinopterygii = 30.27% and Elasmobranchii = 24.71%), reflecting taxonomic uncertainties for fishes, whereas for Invertebrates and Mammalia more than 85% of records were classified as data deficient or inadequate procedure for DNA barcoding. DNA barcoding is a powerful tool to study biodiversity, with a great potential to increase the knowledge of the Southeast Pacific marine biodiversity. Our results highlight the critical need for increasing taxonomic sampling effort, the number of trained taxonomic specialists, laboratory facilities, scientific collections, and genetic reference libraries.

Occurrence of the largetooth sawfish Pristis pristis (Linneaus, 1758) in northern Peru.

The largetooth sawfish (Pristis pristis) is listed as Critically Endangered on the IUCN Red List (Kyne et al. 2013). This species has been recorded in the Eastern Tropical Pacific, where its range has been described as extending from Mazatlan, Mexico, to northern Peru (Chirichigno Cornejo 2001). Recent research efforts suggest that largetooth sawfish are now extremely rare or locally extinct on Mexico's Pacific coast (Bonfil et al. 2018). There is no current information on the status of largetooth sawfish in Panama or Colombia; the most recent record of a largetooth sawfish captured on Colombia's Pacific coast occurred in 2007 (Chasqui et al. 2017). In Ecuador, the species had been considered extirpated. However, in 2014, a large largetooth sawfish was captured by local fisherman in southern Ecuador, taken to the fishing port of Salinas and then released by the environmental agency (Barriga 2012; Rosas-Luis 2014). In Peru, recent reports of largetooth sawfish have been rare, but two captures of largetooth sawfish by fishermen (2014 and 2015) in northern Peru were reported (Mendoza et al. 2017). This confirms that the species is still occasionally encountered in this region.

Taxonomic revision of the Menticirrhus americanus (Linnaeus, 1758) and M. littoralis (Holbrook, 1847) (Percomorphacea: Sciaenidae) species complexes from the western Atlantic.

The genus Menticirrhus is widely distributed in the Neotropical region, where its species are common and abundant in shallow coastal waters and estuaries. The diversity, biogeography, and evolutionary relationships of the Menticirrhus species are still poorly known, due primarily to the difficulty of differentiating the species, given the broad similarities in their external morphology. The present study is based on the analysis of morphological and molecular data, with the examination of type specimens and a comprehensive collection of non-type specimens from an ample geographic range. These analyses indicated that two widely distributed Western Atlantic species, Menticirrhus americanus and M. littoralis, represent species complexes. The M. littoralis species complex is characterized by the absence of dark bars on body side, and a smaller, light-colored pectoral fins, that barely reaching the tip of the depressed pelvic fins, with fewer pectoral-fin rays. This complex includes three species: M. littoralis, found in the Gulf of Mexico, M. gracilis, from the southeastern and southern coast of South America, and a new species, described here, from the northern to eastern Brazilian coast. The M. americanus species complex is characterized by the presence of dark bars on body side, and a large, dark pectoral fin, that surpass the tip of the depressed pelvic fin, with more pectoral-fin rays. This complex has two species, M. americanus, which occurs on the east coast of the United States and in the Gulf of Mexico, and M. martinicensis, found from Caribbean to Argentina, that represents a cryptic allopatric species. An identification key to all species of the genus is presented.

First description of a giant manta ray fetus Mobula birostris (Walbaum 1792) from Tumbes, Peru (Southeast Pacific).

The population of Mobula birostris ("giant manta ray") found in the waters of northern Peru and Ecuador is believed to be the largest in the world (Harding Beirwagen, 2009). This species is considered to be the largest within the group of manta rays, as they attains at least 670 cm disc width (reported to 910 cm) (White et al., 2006) and there is a record of an individual weighing 2000 kg (Kunjipalu Boopendranath, 1981). This species is ovoviviparous (matrotrophic viviparious) (Herbert, 2012). A single pup follows a gestation period of approximently one year, (Marshall et al., 2008, Mendonça et al., 2012). Sucessive pregnancies are speculated to be separated by a refactory period of two or more years (Mendonça et al., 2012). The objective of this study is to record the measurements of a M. birostris fetus of a female caught accidentally in the region of Tumbes, Peru. This is the first record of morphological and morphometric data regarding a manta fetus in Peru.

Review of the harvestfishes, genus Peprilus (Perciformes: Stromateidae), of the Atlantic coast of South America.

Currently, seven valid species are recognized in the genus Peprilus. Found from United States to Argentina, Peprilus paru has a complex nomenclatural history, with seven junior synonyms, three from North America and four from South America. As there has been no recent research, it remains unclear whether species representatives in the north-south axis represent different populations of a single species or distinct species. By comparison of type specimens as well as a comprehensive collection of non-type specimens, this paper aims to clarify the taxonomic status of the nominal species listed as junior synonyms of Peprilus paru in the Atlantic side of South America. Based on morphological data and DNA barcoding, Peprilus crenulatus Cuvier, 1829 and P. xanthurus (Quoy & Gaimard, 1825) are resurrected, while Rhombus argentipinnis Cuvier, 1833 and Rhombus orbicularis Guichenot, 1866, are considered to be junior synonyms of P. crenulatus.

Molecular identification of Atlantic goliath grouper Epinephelus itajara (Lichtenstein, 1822) (Perciformes: Epinephelidae) and related commercial species applying multiplex PCR

The Atlantic goliath grouper, Epinephelus itajara , is a critically endangered species, threatened by illegal fishing and the destruction of its habitats. A number of other closely related grouper species found in the western Atlantic are also fished intensively. While some countries apply rigorous legislation, illegal harvesting followed by the falsification of fish products, which impedes the correct identification of the species, is a common practice, allowing the catch to be marketed as a different grouper species. In this case, molecular techniques represent an important tool for the monitoring and regulation of fishery practices, and are essential for the forensic identification of a number of different species. In the present study, species-specific primers were developed for the Cytochrome Oxidase subunit I gene, which were applied in a multiplex PCR for the simultaneous identification of nine different species of Epinephelidae: Epinephelus itajara , E. quinquefasciatus , E. morio , Hyporthodus flavolimbatus , H. niveatus , Mycteroperca acutirostris , M. bonaci , M. marginata , and M. microlepis . Multiplex PCR is a rapid, reliable and cost-effective procedure for the identification of commercially-valuable endangered fish species, and may represent a valuable tool for the regulation and sustainable management of fishery resources.(AU)

O mero, Epinephelus itajara , encontra-se criticamente ameaçado, resultado da pesca ilegal e destruição dos habitas. Filogeneticamente relacionadas a este táxon encontram-se garoupas que atualmente são intensamente pescadas no Atlântico Oeste. Apesar de leis mais restritivas aplicadas em alguns países, a captura ilegal com a descaracterização morfológica é uma prática comum que impossibilita a identificação correta da espécie permitindo que seja comercializada como garoupas, badejos ou chernes. A este respeito, técnicas moleculares representam ferramentas importantes para o monitoramento e fiscalização da pesca, provando ser essencial, na identificação forense de diversas espécies. Primers espécie-específicos foram desenvolvidos com base no gene Citocromo Oxidase subunidade I que aplicados em PCR-Multiplex possibilitam a identificação simultânea de nove espécies Epinephelidae: Epinephelus itajara , E. quinquefasciatus , E. morio , Hyporthodus flavolimbatus , H. niveatus , Mycteroperca acutirostris , M. bonaci , M. marginata e M. microlepis . A identificação via PCR multiplex de espécies de peixes ameaçadas e comercialmente importantes é um método rápido, prático, seguro e de baixo custo, que poderá ser útil o controle do uso e manejo sustentável de recursos pesqueiros.(AU)

Karyotype of the invasive species Pterois volitans (Scorpaeniformes: Scorpaenidae) from Margarita Island, Venezuela / Cariotipo de la especie invasora Pterois volitans (Scorpaeniformes: Scorpaenidae) de Isla Margarita Island, Venezuela

The genus Pterois includes nine valid species, native to the Red Sea and Indian Ocean throughout the Western Pacific. P. volitans and P. miles are native to the Indo-Pacific, and were introduced into Florida waters as a result of aquarium releases, and have been recently recognized as invaders of the Western Atlantic and Caribbean Sea (Costa Rica to Venezuela). Thus far, cytogenetic studies of the genus Pterois only cover basic aspects of three species, including P. volitans from Indo-Pacific Ocean. Considering the lack of more detailed information about cytogenetic characteristics of this invasive species, the objective of the present study was to investigate the basic and molecular cytogenetic characteristics of P. volitans in Venezuela, and compare the results with those from the original distribution area. For this, the karyotypic characteristics of four lionfish caught in Margarita Island, Venezuela, were investigated by examining metaphase chromosomes by Giemsa staining, C-banding, Ag-NOR, and two-colour-Fluorescent in situ hybridization (FISH) for mapping of 18S and 5S ribosomal genes. Comparing the sequences of the 16S gene of the specimens analyzed, with sequences already included in the Genbank, we corroborated that our specimens identified as P. volitans are in fact this species, and hence exclude the possibility of a misidentification of P. miles. The diploid number was 2n=48 (2m+10sm+36a) with FN=60. Chromosomes uniformly decreased in size, making it difficult to clearly identify the homologues except for the only metacentric pair, and the pairs number two, the largest of the submetacentric series. C-banding revealed only three pairs of chromosomes negative for C-band, whereas all remaining chromosomes presented telomeric and some interstitial C-positive blocks. Only two chromosomes were C-banding positive at the pericentromeric regions. Sequential staining revealed Ag-NOR on the tips of the short arms of chromosome pair number two and the FISH assay revealed that 18S rDNA and 5S rDNA genes are co-located on this chromosome pair. The co-localization of 5S rDNA and 45S rDNA is discussed. Both constitutive heterochromatin and NOR location detected in samples examined in this study, differ from those reported for P. volitans in previous analysis of specimens collected in Indian Ocean (Java), suggesting the occurrence of chromosome microrearrangements involving heterochromatin during the spread of P. volitans.Rev. Biol. Trop. 62 (4): 1365-1373. Epub 2014 December 01.

El género Pterois contiene nueve especies válidas, nativas del Mar Rojo y el Océano Índico en el Pacífico occidental. P. volitans y P. miles son nativas del Indo-Pacífico, y fueron introducidas en las aguas de Florida como resultado de la liberación de peces confinados en acuario y han sido reconocidas recientemente como invasoras en el Atlántico Occidental y Mar Caribe (Costa Rica hasta Venezuela). Los estudios citogenéticos realizados hasta ahora en el género Pterois cubren solamente aspectos básicos de tres especies que incluyen a P. volitans del océano Indo-Pacífico. Debido a la ausencia de información detallada sobre las características cromosómicas de esta especie invasora, el objetivo del presente estudio fue investigar las características citogenéticas en ejemplares de Venezuela mediante técnicas convencionales y moleculares y comparar los resultados con los reportados para el área de distribución original. Para ello, se investigaron las características cariotípicas mediante tinción con Giemsa, bandeo-C, impregnación con Nitrato de Plata (Ag-NOR) e hibridación fluorescente in situ (FISH) dual para localizar los genes ribosomales 18S rDNA y 5S rDNA en cuatro ejemplares de pez león capturados en la Isla Margarita, Venezuela. La comparación de secuencias del gen 16S de los especímenes analizados con secuencias ya incluidas en el Genbank permitieron corroborar la identificación de P. volitans excluyendo así la posibilidad de una identificación errónea de P. miles. El número diploide fue 2n=48 (2m+10sm+36a) con un FN=60. Los cromosomas presentaron tamaños que disminuyen de manera uniforme dificultando la identificación de homólogos, excepto el único par metacéntrico y el par cromosómico número 2. El bandeo-C reveló tres pares de cromosomas bandas-C negativos, mientras que los restantes presentaron bloques bandas-C positivos en posición telomérica y, en algunos casos, intersticial. Sólo dos cromosomas mostraron bandas-C pericentroméricas. La tinción secuencial reveló las Ag-NOR localizadas en los extremos de los brazos cortos del par número dos y el ensayo FISH demostró que los genes 18S rDNA y 5S rDNA se localizan en ese mismo par. Se discute la co-localización de los genes 5S rDNA y 18S rDNA. La distribución de la heterocromatina constitutiva y localización de las NORs en los peces examinados difirió de la reportada para ejemplares de P. volitans del Océano Índico (Java), sugiriendo que durante la propagación de P. volitans han ocurrido reorganizaciones cromosómicas que involucran la heterocromatina.

Morphological and molecular evidence for the occurrence of three Hippocampus species (Teleostei: Syngnathidae) in Brazil.

For many decades only two species of seahorses were recognized from Brazil: Hippocampus reidi Ginsburg, 1933, the long snout seahorse, and H. erectus Perry, 1810, the lined seahorse. The presence of a possible third species, recognized in 2002, brought about the need for a broad revision of the genus in Brazilian waters. A total of 335 specimens of seahorses, obtained from Brazilian and other collections, representing the three putative species from Brazil were analyzed: H. reidi, the species of greatest abundance and occurs in estuaries and the sea; H. erectus, which occurs only in the sea, and Hippocampus patagonicus was also determined to be present based on multiple specimens. Our morphometric / numerical and molecular analysis showed that the species currently identified as H. erectus in Brazil is actually H. patagonicus Piacentino & Luzatto, 2004. The existence of a possible third species, was instead based on the true H. erectus, as confirmed in the present study by the study of classical systematic and mitochondrial analysis. Thus, we recognize three species of seahorses in Brazil: H. erectus, H. reidi and H. patagonicus.

Karyotype of the invasive species Pterois volitans (Scorpaeniformes: Scorpaenidae) from Margarita Island, Venezuela.

The genus Pterois includes nine valid species, native to the Red Sea and Indian Ocean throughout the Western Pacific. P. volitans and P. miles are native to the Indo-Pacific, and were introduced into Florida waters as a result of aquarium releases, and have been recently recognized as invaders of the Western Atlantic and Caribbean Sea (Costa Rica to Venezuela). Thus far, cytogenetic studies of the genus Pterois only cover basic aspects of three species, including P. volitans from Indo-Pacific Ocean. Considering the lack of more detailed information about cytogenetic characteristics of this invasive species, the objective of the present study was to investigate the basic and molecular cytogenetic characteristics of P. volitans in Venezuela, and compare the results with those from the original distribution area. For this, the karyotypic characteristics of four lionfish caught in Margarita Island, Venezuela, were investigated by examining metaphase chromosomes by Giemsa staining, C-banding, Ag-NOR, and two-colour-Fluorescent in situ hybridization (FISH) for mapping of 18S and 5S ribosomal genes. Comparing the sequences of the 16S gene of the specimens analyzed, with sequences already included in the Genbank, we corroborated that our specimens identified as P. volitans are in fact this species, and hence exclude the possibility of a misidentification of P. miles. The diploid number was 2n = 48 (2m + 10sm + 36a) with FN = 60. Chromosomes uniformly decreased in size, making it difficult to clearly identify the homologues except for the only metacentric pair, and the pairs number two, the largest of the submetacentric series. C-banding revealed only three pairs of chromosomes negative for C-band, whereas all remaining chromosomes presented telomeric and some interstitial C-positive blocks. Only two chromosomes were C-banding positive at the pericentromeric regions. Sequential staining revealed Ag-NOR on the tips of the short arms of chromosome pair number two and the FISH assay revealed that 18S rDNA and 5S rDNA genes are co-located on this chromosome pair. The co-localization of 5S rDNA and 45S rDNA is discussed. Both constitutive heterochromatin and NOR location detected in samples examined in this study, differ from those reported for P. volitans in previous analysis of specimens collected in Indian Ocean (Java), suggesting the occurrence of chromosome microrearrangements involving heterochromatin during the spread of P. volitans.