Abstract in English:ABSTRACT The following letter, from a network of women zoologists, is a reply to the article of AlShebli et al. (2020), which suggests that female protégés reap more benefits when mentored by men and concludes that female mentors hinder the success of their female protégés and the quality of their impact. This contribution has two parts. First, we highlight the most relevant methodological flaws which, in our opinion, may have impacted the conclusions of AlShebli et al. (2020). Second, we discuss issues pertaining to women in science, bring a perspective of Women in Zoology and discuss how current diversity policies are positively changing our field.
Abstract in English:ABSTRACT The bluefish, Pomatomus saltatrix (Linneus 1766) is captured by industrial, artisanal, and recreational fisheries throughout its distribution range. The reproductive biology of P. saltatrix in the southwestern Atlantic was studied using 1,102 specimens captured by the Brazilian commercial fleet between March 2014 and December 2015. The recruitment period was identified from records of juveniles in experimental beach seine hauls carried out on sandy beaches in the external sector of Guanabara Bay for four years (2012-2015). Based on the reproductive indices and on the macro- and microscopic analyses of the gonads, spawning peaks were identified in autumn and spring. The size at first maturity was estimated at 35.5, 38.3, and 37.4 cm for females, males, and general, respectively. Ovary analyses and measurements of the oocyte diameters indicated that bluefish are multiple spawners with asynchronous oocyte development. The batch fecundity estimate was 202,752.5 eggs and ranged from 9,800.9 to 426,787.0 eggs. The species reproduces throughout the entire study area, but it is more active in the south of Arraial do Cabo. The young-of-the-year were recorded on shallow water in all seasons, with modal peaks in the summer months. The parameters estimated in this study expand and update information on this species, providing important data for the evaluation and fisheries management of the stock of P. saltatrix in the southwestern Atlantic.
Abstract in English:ABSTRACT This study provides a comprehensive checklist of Odonata species from the protected area of Mananciais da Serra. The survey was conducted in the endangered Atlantic Forest domain at the southern Serra do Mar mountain chain within a well-preserved area in the municipality of Piraquara, state of Paraná, Brazil. Adults and larvae were sampled between June 2017 and March 2020 using different techniques in numerous mesohabitats, including phytotelmata, pools, small streams, and large reservoirs. A total of 1,708 specimens from 9 families, 43 genera and 84 species were sampled resulting in 53 new records for the state of Paraná, almost doubling the known occurrence records for dragonflies and damselflies in that state. Furthermore, two hitherto undescribed females from the genera Planiplax and Heteragrion, four ultimate stadium larvae from Planiplax, Neocordulia, Heteragrion, and Acanthagrion, and five undescribed species were detected, one each from the genera Heteragrion, Progomphus, Brechmorhoga, Erythrodiplax, and Dasythemis. The estimated richness of odonates in this area is greater than 100 species, while the observed richness corresponding to almost 10% of all Odonata species in Brazil, the species-richest country in the world. These results reiterate the need to investigate undersampled areas to improve knowledge on diversity, taxonomy, and distribution of neotropical species. Finally, taxonomic notes for some species, including the rare corduliid Neocordulia mambucabensis Costa & T.C. Santos, 2000, are provided.
Abstract in English:ABSTRACT A new species, Spilomena capatrata Bashir & Ma, sp. nov. is described from Palearctic and Oriental China. Additionally, eleven species are reported, of which five are new records from China: S. beata Blüthgen, S. hainesi N. Smith, S. menkei R. Bohart, S. punctatissima Blüthgen, and S. valkeilai Vikberg. A key to Chinese species of Spilomena Shuckard is also provided.
Abstract in English:ABSTRACT Ornamentula Kisielewski, 1991 is a monospecific genus in Order Chaetonotida. The sole species, O. paraensis Kisielewsk, 1991, is a semiplanktonic gastrotrich found in a single pond in the Amazon region of Brazil. Herein we describe a new species of the genus Ornamentula, collected in a small urban lagoon in the Atlantic Forest of southeast Brazil. Ornamentula miyazakii sp. nov. resembles O. paraensis, but it shows differences in the ornamented trunk scales and spinal spines distribution, sufficient to proposte it as it’s a new species.
Abstract in English:ABSTRACT The response mechanism and interaction patterns of HIF-1α and p53 in animals in an hypoxic environment are crucial for their hypoxic tolerance and adaptation. Many studies have shown that underground rodents have better hypoxic adaptation characteristics. However, the mechanism by which HIF-1α and p53 in underground rodents respond to hypoxic environments compared with in ground rodents remains unclear. Further, whether a synergy between HIF-1α and p53 enables animals tolerate extremely hypoxic environments is unclear. We studied HIF-1α and p53 expression in the brain tissue and cell apoptosis in the hippocampal CA1 region during 6 hours of acute hypoxia (5% oxygen) in Lasiopodomys mandarinus (Milne-Edwards, 1871) and Lasiopodomys brandtii (Radde, 1861), two closely related small rodents with different life characteristics (underground and aboveground, respectively), using a comparative biology method to determine the mechanisms underlying their adaptation to this environment. Our results indicate that HIF-1α and p53 expression is more rapid in L. mandarinus than in L. brandtii under acute hypoxic environments, resulting in a significant synergistic effect in L. mandarinus. Correlation analysis revealed that HIF-1α expression and the apoptotic index of the hippocampal CA1 regions of the brain tissues of L. mandarinus and L. brandtii, both under hypoxia, were significantly negatively and positively correlated, respectively. Long-term existence in underground burrow systems could enable better adaptation to hypoxia in L. mandarinus than in L. brandtii. We speculate that L. mandarinus can quickly eliminate resulting damage via the synergistic effect of p53 and HIF-1α in response to acute hypoxic environments, helping the organism quickly return to a normal state after the stress.
Abstract in English:ABSTRACT Larkinia grandis (Broderip & G.B. Sowerby I, 1829), an important fishing resource for Mexican communities, is an Arcidae clam. It is also considered a species with aquaculture potential. In this work we investigated the gonadal phases and sexuality in a population of L. grandis in the Gulf of California. Our findings support the hypothesis that there is one male per female in the population studied. It also documents that the shape, position and color of the gonads of L. grandis are consistent with observations in other Arcidae species. Additionally, five gonadal phases are differentiated and described in males and females (development, mature, spawning, post-spawning and resting), with a noticeable presence of brown cells during post-spawning and the onset of the resting phase, suggesting that those cells are involved in the reabsorption of remnants. Additionally, asynchronous gametogenesis in males, synchronic gametogenesis in females and batch spawning are defined. The results of this contribution can be used in the efforts to protect this bivalve.
Abstract in English:ABSTRACT Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.
Abstract in English:ABSTRACT The flavipes group of Pachyprotasis Hartig, 1837, with twenty-four species recognized in China, is reviewed. This number includes two newly described species, Pachyprotasis rufodorsata sp. nov., from Sichuan, Hubei, Ningxia, and Shaanxi provinces, and Pachyprotasis nigritarsalia sp. nov., from Hunan province. The mesopleuron and metapleuron of the two new species are reddish-brown, distinguishing them from other similar species of the P. flavipes group. Thirty-four species of this group have been recorded from China, one species (P. variegate Fallén, 1808) was found to be widespread throughout Europe and Siberia, twenty-four were originally described from the China and Burma-Yunnan frontier, eleven from India, and five from Japan. A key to the species of this group from China is provided.
Abstract in English:ABSTRACT Plants and insects have co-existed for millions of years. Although research has been conducted on various insect species that induce galls on various plant tissues, information is particularly scarce when it comes to insects that form galls on the tough trunk of their host plants. This contribution describes the gall-inducing aphid Nipponaphis hubeiensis sp. nov. from the Zhushan County, Shiyan City, Hubei Province of China. This aphid induces enclosed galls with woody external layer on the trunk of Sycopsis sinensis (Saxifragales: Hamamelidaceae), an uncommon ecological niche in the aphid-plant interaction system. Morphological features for the identification of new species are provided. In addition, a partial sequence of the nuclear gene EF1α was amplified and sequenced to construct a cluster graph. Based on the clustering graph combined with morphology traits, the gall-forming aphid was classified into Nipponaphis. The unique ecological habits of this new aphid will bring innovative perspectives to the study of the evolution and diversity in aphid-host interaction.
Abstract in English:ABSTRACT Five species of Strongylogaster Dahlbom, 1835 are recorded from Zhejiang Province, China. They are four known species, S. formosana (Rohwer, 1916), S. macula (Klug, 1817), S. takeuchii Naito, 1980 and S. xanthocera (Stephens, 1835), and a new species. Strongylogaster tianmunica sp. nov., collected from Mt. Tianmu in Zhejiang Province, is here described and illustrated. This new species resembles S. nantouensis Naito, 1990, but differs from the latter by the following characters: female body length 10-12 mm, male body length 8-10 mm; tegula brown to dark brown; pronotum largely yellowish-white; trochanters black, apical half of hind femora and of hind tibiae yellowish-white; malar space as long as radius of median ocellus; antennomere 3 as long as antennomere 4; and ovipositor apical sheath with distinct lateral scapes. A key to the five species of Strongylogaster from Zhejiang Province is provided.
Abstract in English:ABSTRACT Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.
Abstract in English:ABSTRACT Bardaxima Walker, 1858 includes 12 species, eight of them occurring in Brazil. The Brazilian species are treated here, including diagnoses and illustrations of both adults and genitalia to allow their identification: B. donatian (Schaus), B. fulgurifera (Walker, 1869), stat. rev. (= demea (Druce, 1895)); B. ionia (Druce, 1900) (= albolimbata (Dognin, 1909), syn. nov., B. ambigua (Dyar, 1908), syn. nov., B. metcalfi (Schaus, 1928), syn. nov.); B. lucilinea Walker, 1858; B. marcida (C. Felder, 1874); B. procne (Schaus, 1892) (= meyeri (Schaus, 1928), syn. nov.); B. sambana (Druce, 1895), stat. rev. (= belizensis Thiaucourt, 2010, syn. nov., bolivari Thiaucourt, 2010, syn. nov., coloradorum Thiaucourt, 2010, syn. nov., panamensis (Draudt, 1932), syn. nov.); B. subrutila (Dognin, 1908); and B. terminalba Jones, 1908 (= oakley (Schaus, 1939)). Bardaxima perses Druce, 1900 is transferred to Elasmia Möschler, 1883 as a new combination, Elasmia perses (Druce, 1900). Stragulodonta gen. nov. is proposed to accommodate Heterocampa stragula Möschler, 1883, comb. nov. (= belua (Draudt, 1932), syn. nov.).
Abstract in English:ABSTRACT Among the predatory ladybird beetles (Coccinellidae: Coleoptera), members of the Coccinellini, predators of aphids and psyllids, stand out. Although the beneficial status of these beetles has been acknowledged by biological control researchers, there are no keys or detailed studies on the immature stages of South American Coccinellidae, especially Coccinellini. We provide descriptions and illustrations of the immatures and adults of major predatory Coccinellini species in southern Brazil along with an identification key for fourth instar larvae and pupae. The following species are included: Cycloneda sanguinea (Linnaeus, 1763), Eriopis connexa (Germar, 1824), Harmonia axyridis (Pallas, 1773), Hippodamia convergens Guérin-Méneville, 1842 and Olla v-nigrum (Mulsant, 1866). The morphological study, which included the use of scanning electron microscopy, revealed new characters such as the type of tarsal claws, spiracles, chalazae, parascoli and strumae. The identification key provided here may be useful in biological control programs.
Abstract in English:ABSTRACT Two new monogenoidean species of Unilatus Mizelle & Kritsky, 1967 found in the gills of loricariids in the Lower Xingu-Iriri rivers are described: Unilatus humboldtii sp. nov. from Baryancistrus niveatus (Castelnau, 1855), Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010, Pseudacanthicus sp. (type-host), and Scobinancistrus aureatus Burgess, 1994; and Unilatus luciarappae sp. nov. from P. armbrusteri. Unilatus humboldtii sp. nov. is distinguished from other congeneric species due to its anterior anchor with well-developed superficial root with depressed or truncated distal portion, and inconspicuous or reduced deep root; anterior bar with posteromedial projection; hooks of pair 1 with dilated shaft comprising 2/3 of the hook length; spiraled male copulatory organ with approximately 16-18 counterclockwise loops. Unilatus luciarappae sp. nov. is characterized by having anterior anchor with well-developed superficial root and reduced deep root, slightly curved shaft, elongated, slightly curved, and tapered point; spiraled MCO with approximately 18-19 counterclockwise loops, with median distal bulbous portion and remaining portion tapered and elongated, comprising 1/4 of the body length; and accessory piece comprising approximately 2/3 of the MCO length. More than fifty years after the description of the type species of Unilatus from an artificial environment (U.S. aquaria), this study represents the first formal record and description of Unilatus species from hosts collected in natural habitats in the Xingu River. Considering the impact of the Belo Monte dam on the formerly pristine conditions of the study region and the importance of loricariids for the ornamental fish trade, we recommend monitoring monogenoidean diversity, parasite-host interaction, as well as the dispersion patterns and pathogenicity of these parasites.
Abstract in English:ABSTRACT This study concerns the diplopod genus Eucampesmella Schubart, 1955, widespread in Brazil. After this work, the genus includes 12 valid species, and three incertae sedis: E. pugiuncula (Schubart, 1946), E. brunnea Kraus, 1959 and E. schubarti Kraus, 1957. The type-species, Eucampesmella tricuspis (Attems, 1931), is redescribed based on the holotype, and the following six new Brazilian species are added: Eucampesmella macunaima sp. nov. from the states of Rondônia, Pará, and Piauí; E. capitu sp. nov. from the states of Piauí and Paraíba; E. brascubas sp. nov. from the state of Sergipe; E. iracema sp. nov. from the state of Pernambuco; E. pedrobala sp. nov. from the state of Ceará; and E. lalla sp. nov. from the state of Rio Grande do Norte. Furthermore, E. lartiguei ferrii (Schubart, 1956) is recognized as a junior synonym of E. lartiguei lartiguei (Silvestri, 1897), which also had its status changed, and E. sulcata (Attems, 1898) is revalidated, prevailing under the name Leptodesmus tuberculiporus Attems, 1898. In addition, drawings, diagnoses, and distribution maps for all species of the genus are provided.
Abstract in English:ABSTRACT Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.
Abstract in English:ABSTRACT Three new species of Urocleidoides Mizelle & Price, 1964 are described from the gills of characiform fishes in the Tocantins River and its tributaries. Urocleidoides boulengerellae sp. nov. is described from Boulengerella cuvieri (Spix & Agassiz, 1829) and differs from all its congeners by the dorsal bar with a long posteromedial projection; male copulatory organ with 2-3 counterclockwise rings and a base with a flange; an accessory piece comprising a robust Y-shaped unit and a sheath-like unit; and a highly sclerotized vaginal canal. Urocleidoides paratriangulus sp. nov., described from Psectrogaster amazonica Eigenmann & Eigenmann, 1889, Cyphocharax gouldingi Vari, 1992, Caenotropus labyrinthicus (Kner, 1858) and Mylesinus paucisquamatus Jégu & Santos, 1988, is most similar to Urocleidoides triangulus (Suriano, 1981) Rossin & Timi, 2016 based on the shape of the anchors and bars but differs from U. triangulus in the morphology of the projection of the dorsal bar, the number of rings of male copulatory organ, and by the smaller size of members of hook pairs 1 and 5 compared with those of the remaining pairs. Urocleidoides tocantinensis sp. nov. is easily distinguished from all other species of the genus by the morphology of the vagina, which present a vaginal vestibule with a membranous cap. Urocleidoides triangulus is reported from its type host in the Guandu River, state of Rio de Janeiro. The present study increases the number of Urocleidoides species to 37 recognized species that fit all the generic characters.
Abstract in English:ABSTRACT Quichuana Knab, 1913 is a Neotropical genus of flower flies (Diptera: Syrphidae) with 50 valid species. Adults of this genus are flower visitors and their larvae are usually associated with the phytotelmata of bromeliads and heliconias, actively participating in the recycling of nutrients in forest environments. Despite their importance in ecosystem dynamics, Quichuana larvae are poorly known. Herein we describe the immature stages of Quichuana pogonosa Fluke, 1937 from samples collected from the phytotelmata of two terrestrial bromeliad species in the state of Paraná, Brazil. We provide illustrations of the egg, third instar larva and puparium, as well as information on the life cycle of the species. Additionally, we describe and illustrate the male genitalia and present the DNA-barcoding based on larva and adult specimens.
Abstract in English:ABSTRACT A new species of the pseudoscorpion genus Cystowithius Harvey, 2004 is described based on several males and females collected in the Cordillera Central near Manizales and Villamaría, Caldas, Colombia. The type series was collected under or on the bark of Eucalyptus grandis W. Hill ex Maiden (Myrtaceae). Cystowithius ankeri sp. nov. is the fifth species in the genus, differing from its four congeners by several characters, including the position of the male sternal invaginations, the length of the movable finger of the pedipalp, and the tactile setae of tarsus IV situated subdistally. A revised identification key to the five species of Cystowithius is also presented. The first barcode (COI gene) of a species of this genus is also provided.
Abstract in English:ABSTRACT In recent years, our knowledge of the Oriental fauna of Neriidae has improved with the studies of Telostylus Bigot, 1859 and Teloneria Aczél, 1954. However, the small genera (less than three species) have never been revised and their taxonomy remains obscure. Neriidae has 18 genera of which 10 occur exclusively in the Oriental and Australasian Regions, including four monotypic genera, of which one, Protonerius de Meijere, 1924, is only known from the female holotype of Protonerius guttipennis de Meijere, 1921 from Indonesia. We here describe a second species of the genus, Protonerius opacus sp. nov., based on a female specimen from Selangor, Malaysia, which differs from the type species of the genus by the patterns of infuscate spots on the wing and the coloring of pleuron and femora. Additionally, an identification key for the two species and an updated diagnosis of the genus are provided.
Abstract in English:ABSTRACT Information on the breeding biology of most Neotropical birds, and interpopulation comparisons, are insufficient. The Helmeted Manakin, Antilophia galeata (Lichtenstein, 1823), is a forest understory passerine commonly found in the gallery forests of the tropical savanna-like Cerrado biome. We provide information about the nesting phenology, nesting cycle, nests, eggs, nestlings, and nest-site characteristics of a population of the Helmeted Manakin in the state of São Paulo, southeastern Brazil. During two breeding seasons we found 16 active, and 30 inactive nests. Breeding activities occurred from mid- August to mid- January, and nests were constructed in bushes and saplings in the forest’s understory, 0.45-3.48 m above ground (1.56 ± 0.66 m). Clutch size was two eggs, which were laid in intervals of one to three days. Three remarkable patterns of interclutch egg color and marking variations were observed. The incubation period of two nests was 18 and 19 days, and nestling periods were 16.3 ± 0.6 days (16-17 days, n = 3 nests). The apparent nest survival of 11 thoroughly monitored nests was 36.4%. In addition to the first description of the interclutch egg pattern variations, the following information differs from previous literature data: egg laying interval and nestling periods. Our data contribute to the overall knowledge of the variations in breeding parameters of the Helmeted Manakin.
Abstract in English:ABSTRACT The aim of this study was to describe the testisac microanatomy and spermatogenesis of Helobdella simplex (Moore, 1911). The leeches were collected in the Sauce Chico River (Tornquist) during April 2012. The collection of material was carried out manually by checking rocks, logs, leaves and artificial substrates in the river bed. Helobdella simplex has six pairs of testisacs located between the gastric caeca. The testisac wall has two structurally and functionally differentiated cell types: the lining mesothelial cells and the germline cells. The lining cells are flat and form a continuous layer. In H. simplex no ciliated cells were observed into the testisacs, nor the formation of spermatogonia due to detachment of the testicular wall. Cell types were microscopically characterized, and five spermatogenesis stages are described, taking into account the maturation of germinal cells, the morphological changes in the cytophore and phagocytic activity. Testicular phagocytes actively participate during spermatogenesis. They are involved both in the removal of defective cells during the early stages of spermatogenesis and in the removal of the cytophore during the reacting reabsorption. Our study adds the knowledge of spermatogenesis in H. simplex and might be useful to differentiate the stages of development during the reproductive cycle, and to interpret aspects of its population dynamics.
Abstract in English:ABSTRACT The tropical anguillid eel, Anguilla bicolor McCelland, 1844, includes two subspecies, Anguilla bicolor bicolor McCelland, 1844 and Anguilla bicolor pacifica Schmidt, 1928, and is distributed across the Indo-Pacific region. Although A. bicolor is widely distributed and recognized as an important fish resource in the Indo-Pacific region, few studies have been conducted on its genetic variation and population structure. DNA barcoding of A. bicolor specimens collected in the Indo-Pacific region was carried out in this study using mitochondrial cytochrome c oxidase subunit I. Anguilla bicolor was found to diverge genetically, which supported its classification into two different subspecies. In addition, our study showed that A. bicolor bicolor had two genetically distinct populations/groups, and these different populations co-occur geographically in Indonesia and Malaysia in the eastern Indian Ocean. Our findings suggest that the eel larvae might be transported from at least two geographically different spawning grounds in the Indian Ocean, and then recruited to and settled in the same habitats in Indonesian and Malaysian waters. The molecular evidence calls for further research on the life history, stock assessment and protection of the populations of A. bicolor bicolor in Indonesia and Malaysia.
Abstract in English:ABSTRACT Although the giant mottled eel, Anguilla marmorata Quoy & Gaimard, 1824, is widely distributed in the Indo-Pacific region, few ecological studies have been conducted on the species. We investigated the stomach contents of A. marmorata visually and used the DNA-barcode region of the mitochondrial cytochrome c oxidase subunit 1 (CO1) to confirm the species’ identification. The stomach content analysis revealed that teleosts and crustaceans are the major prey items of A. marmorata. Interestingly, the stomach content of one of the specimens, which was 1029 mm in total length (TL), contained an eel-like fish identified as A. marmorata measuring 510 mm in TL. This study is the first to record cannibalism in the diet of A. marmorata. Although the diet of anguillid eels is generally selective for a single prey species, larger eels are more likely to adopt a diverse feeding habit that includes cannibalism in the tropical river ecosystems.