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1.
Parasitol Res ; 123(5): 200, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38696061

ABSTRACT

The humpback whale (Megaptera novaeangliae) is a cosmopolitan migratory, seasonal mysticete that frequents the Brazilian coast. Strands of specimens may occur during the migratory stay in the country. In 2021 and 2022, three live humpback whales stranded on the coast of Rio Grande do Sul and Santa Catarina states in southern Brazil. After euthanasia, specimens were necropsied, and organs were thoroughly examined for lesions. Grossly, in all three cases, the liver exhibited multifocal, irregular, firm, white areas on the hepatic capsule, which extended into the parenchyma. On the cut surface, the livers were yellow to pale brown with orangish to greenish areas, the bile ducts were prominent, thickened, and severely dilated, and leaf-shaped flukes were found inside of them. Additionally, one case showed moderate atrophy of the right hepatic lobe. The histological findings included dilation of bile ducts, hyperplasia of the bile duct epithelium, marked inflammatory infiltration of lymphocytes, plasma cells, and eosinophils, and portal fibrosis. The parasite Brachycladium goliath was both morphologically and molecularly identified based on diagnostic key for trematodes and the original description of the species, and the amplification and sequencing of the ITS-2 region, respectively. Even though hepatic injury was not the primary cause of stranding, it may have contributed to the debilitation of the whales. To the authors' knowledge, this is the first study that reports M. novaeangliae as a definitive host of B. goliath and that describes the lesions caused by the parasite in cetaceans.


Subject(s)
Humpback Whale , Liver , Trematoda , Trematode Infections , Animals , Humpback Whale/parasitology , Brazil , Trematoda/classification , Trematoda/anatomy & histology , Trematoda/isolation & purification , Trematoda/genetics , Liver/parasitology , Liver/pathology , Trematode Infections/veterinary , Trematode Infections/parasitology , Phylogeny , Male
2.
J Fish Biol ; 104(6): 1940-1946, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38551100

ABSTRACT

This report updates our understanding of whale shark occurrences in The Bahamas by drawing upon a variety of data sources. Our findings reveal previously unreported sighting locations, often associated with tourism activities, underscoring the pivotal role played by nontraditional data sources in addressing knowledge gaps. These revelations emphasize the ongoing necessity for monitoring efforts. Additionally, we have found cases that raise concerns related to unregulated human-shark interactions in the region, highlighting the pressing need for sustainable tourism practices within Bahamian waters.


Subject(s)
Conservation of Natural Resources , Sharks , Tourism , Animals , Bahamas
3.
Animals (Basel) ; 13(24)2023 Dec 06.
Article in English | MEDLINE | ID: mdl-38136800

ABSTRACT

Cetaceans are well known for their unique behavioral habits, such as calls and tactics. The possibility that these are acquired through social learning continues to be explored. This study investigates the ability of a young beluga whale to imitate novel behaviors. Using a do-as-other-does paradigm, the subject observed the performance of a conspecific demonstrator involving familiar and novel behaviors. The subject: (1) learned a specific 'copy' command; (2) copied 100% of the demonstrator's familiar behaviors and accurately reproduced two out of three novel actions; (3) achieved full matches on the first trial for a subset of familiar behaviors; and (4) demonstrated proficiency in coping with each familiar behavior as well as the two novel behaviors. This study provides the first experimental evidence of a beluga whale's ability to imitate novel intransitive (non-object-oriented) body movements on command. These results contribute to our understanding of the remarkable ability of cetaceans, including dolphins, orcas, and now beluga whales, to engage in multimodal imitation involving sounds and movements. This ability, rarely documented in non-human animals, has significant implications for the development of survival strategies, such as the acquisition of knowledge about natal philopatry, migration routes, and traditional feeding areas, among these marine mammals.

4.
Bull Environ Contam Toxicol ; 112(1): 18, 2023 Dec 23.
Article in English | MEDLINE | ID: mdl-38141110

ABSTRACT

The whale shark (Rhincodon typus) is a filter-feeding organism that can be considered a sentinel species, and Bahía de los Ángeles (BLA) in the Gulf of California is an important sighting site for these elasmobranchs. This filter-feeding organism can be considered a pollutant sampler from the marine environment. Persistent organic pollutants are toxic compounds with high mobility and environmental persistence, bioaccumulation and trophic transfer. Among these are polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). The present work aimed to determine concentrations of PAHs and OCPs in whale shark skin biopsies, collected in 2021 at BLA. Mean detected levels of PAHs and OCPs were 279.4 ng/g dw (dry weight) and 1478.1 ng/g dw, respectively. Analysis of similarities between the ordered sizes (4.2-7.6 m) and the concentrations of PAHs and OCPs indicated no significant differences. Individual PAHs detected indicate pyrogenic and petrogenic sources; the presence of pesticides at levels higher than those of hydrocarbons may be related to agricultural activity in the areas surrounding the Baja California peninsula. This study is the first report of PAH levels in R. typus for the Gulf of California and Mexico.


Subject(s)
Hydrocarbons, Chlorinated , Pesticides , Polycyclic Aromatic Hydrocarbons , Sharks , Water Pollutants, Chemical , Animals , Mexico , Environmental Monitoring , Persistent Organic Pollutants , Brazil , Los Angeles , Pesticides/analysis , Hydrocarbons, Chlorinated/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Biopsy , Water Pollutants, Chemical/analysis
5.
Biomimetics (Basel) ; 8(5)2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37754151

ABSTRACT

In this work, an approach is proposed to solve binary combinatorial problems using continuous metaheuristics. It focuses on the importance of binarization in the optimization process, as it can have a significant impact on the performance of the algorithm. Different binarization schemes are presented and a set of actions, which combine different transfer functions and binarization rules, under a selector based on reinforcement learning is proposed. The experimental results show that the binarization rules have a greater impact than transfer functions on the performance of the algorithms and that some sets of actions are statistically better than others. In particular, it was found that sets that incorporate the elite or elite roulette binarization rule are the best. Furthermore, exploration and exploitation were analyzed through percentage graphs and a statistical test was performed to determine the best set of actions. Overall, this work provides a practical approach for the selection of binarization schemes in binary combinatorial problems and offers guidance for future research in this field.

6.
Appl Math Model ; 121: 506-523, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37234701

ABSTRACT

A new contagious disease or unidentified COVID-19 variants could provoke a new collapse in the global economy. Under such conditions, companies, factories, and organizations must adopt reopening policies that allow their operations to reduce economic effects. Effective reopening policies should be designed using mathematical models that emulate infection chains through individual interactions. In contrast to other modeling approaches, agent-based schemes represent a computational paradigm used to characterize the person-to-person interactions of individuals inside a system, providing accurate simulation results. To evaluate the optimal conditions for a reopening policy, authorities and decision-makers need to conduct an extensive number of simulations manually, with a high possibility of losing information and important details. For this reason, the integration of optimization and simulation of reopening policies could automatically find the realistic scenario under which the lowest risk of infection was attained. In this paper, the metaheuristic technique of the Whale Optimization Algorithm is used to find the solution with the minimal transmission risk produced by an agent-based model that emulates a hypothetical re-opening context. Our scheme finds the optimal results of different generical activation scenarios. The experimental results indicate that our approach delivers practical knowledge and essential estimations for identifying optimal re-opening strategies with the lowest transmission risk.

7.
J Fish Biol ; 103(2): 448-452, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37211541

ABSTRACT

Despite being the world's largest fish, many questions remain regarding the ecology and behaviour of the whale shark (Rhincodon typus). We present the first direct evidence of whale sharks engaging in bottom-feeding behaviour and provide potential explanations for this foraging strategy. We suggest that whale sharks actively feed on benthic prey, either predominantly in deepwater environments or where the abundance of such prey exceeds that of planktonic food sources. We also highlight the potential for ecotourism and citizen science projects to contribute to our understanding of marine megafauna behavioural ecology.


Subject(s)
Feeding Behavior , Sharks , Animals , Ecology
8.
Mar Pollut Bull ; 192: 115086, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37236093

ABSTRACT

The impacts of microplastics on filter feeders megafauna have recently received increased attention. These organisms are potentially exposed to plastic ingestion and the release of added/sorbed contaminants during feeding activities. An assessment of microplastic abundance and the chemical impact of Phthalates esters (PAEs) were performed in neustonic samples and skin biopsies of Balaenoptera physalus and Rhincodon typus inhabiting the Gulf of California (Mexico). Sixty-eight percent of the net tows contained plastics with a maximum of 0.24 items/m3 mainly composed of polyethylene fragments. PAE levels were detected both in environmental and skin biopsy samples, with the highest values in the fin whale specimens (5291 ng/g d.w). Plasticizer fingerprint showed a similar distribution pattern between neustonic samples and filter-feeding species, with DEHP and MBP having the highest concentrations. The detection of PAE levels confirmed their potential role as plastic tracers and give preliminary information about the toxicological status of these species feeding in La Paz Bay.


Subject(s)
Microplastics , Plastics , Bays , Mexico , Biopsy
9.
Emerg Infect Dis ; 29(1): 214-217, 2023 01.
Article in English | MEDLINE | ID: mdl-36573734

ABSTRACT

Cetacean morbillivirus (CeMV) causes illness and death in cetaceans worldwide; the CeMV strains circulating in the Southern Hemisphere are poorly known. We detected a pilot whale CeMV strain in 3 short-finned pilot whales (Globicephala macrorhynchus) stranded in Brazil during July-October 2020. Our results confirm this virus circulates in this species.


Subject(s)
Morbillivirus Infections , Morbillivirus , Whales, Pilot , Animals , Morbillivirus Infections/diagnosis , Morbillivirus Infections/veterinary , Brazil/epidemiology , Morbillivirus/genetics
10.
Rev. bras. parasitol. vet ; 32(4): e013423, 2023. tab, graf
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1521813

ABSTRACT

Abstract New morphological, morphometric and scanning electron microscopy data of a nematode of the family Anisakidae, recovered from a specimen of Kogia sima, a cetacean that died off the northern coast of Brazil, are presented in this paper. Morphological features such as the violin-shaped ventricle and short and equal spicules, as well as the distribution of post-cloacal papillae and specificity for the definitive host (Kogiidae cetaceans) demonstrate similarity to Skrjabinisakis paggiae. This research records Kogia sima and S. paggiae on the estuarine coast of Pará, northern Brazil.


Resumo São apresentados, neste trabalho, novos dados morfológicos, morfométricos e de microscopia eletrônica de varredura de um nematoide da família Anisakidae, recuperado de Kogia sima, um cetáceo que veio a óbito na costa norte do Brasil. Características morfológicas, como o ventrículo em forma de violino, espículos curtos e iguais, além da distribuição de papilas pós-cloacais e especificidade pelo hospedeiro definitivo (cetáceos Kogiidae) demonstram similaridade a Skrjabinisakis paggiae. Esta pesquisa registra Kogia sima e S. paggiae na costa estuarina paraense, norte do Brasil.

11.
Arch. Clin. Psychiatry (Impr.) ; Arch. Clin. Psychiatry (Impr.);48(6): 245-249, Nov.-Dec. 2021. tab
Article in English | LILACS-Express | LILACS | ID: biblio-1364292

ABSTRACT

ABSTRACT Background: Online Challenge is neither an application nor an internet-based game; instead, users receive a link to it via chat groups on social media. Our aim is to identify the potential differences between the normal population and youth drawn to online challenges. These potential differences are the examining the parenting skills of parents of children who participate in the challenges and determining underlying psychopathologies through structured clinical interviews. Method: A questionnaire-based cross-sectional study was used to obtain further in-depth information on the comorbid psychopathology of children who play the BWC and on the parenting skills. The Development and Well Being Assessment and Alabama Parenting Questionnaire was applied to the children and their families in both the control and case groups. Results: Two groups of children and parents were recruited: a clinical sample (case) group (n = 34) and a community sample (control) group (n = 141). Attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), specific phobia and CD (conduct disorder) were significantly more frequent in the clinical sample than in the community sample. The median scores for the Alabama Parenting Questionnaire (APQ) parental involvement, positive parenting, and poor monitoring/supervision subscales were significantly lower in the clinical sample than in the community sample. Conclusion: As far as we know, this study is the first to examine comorbid psychopathologies of online challenge-style games and parenting skills. We believe that as research into these subject increases, it will assist mental health professionals to develop prevention strategies and to manage cases resulting from the Blue Whale Challenge (BWC) and other online challenges that pose a serious threat to mental health and that have driven many young people to suicide worldwide.

12.
Transbound Emerg Dis ; 68(4): 1736-1743, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33070446

ABSTRACT

The humpback whale (HW; Megaptera novaeangliae) population that seasonally resides along the Brazilian coast concentrates in the Abrolhos Bank (Bahia and Espírito Santo states) for breeding during austral winter and spring. Cetacean morbillivirus (CeMV, Paramyxoviridae family) is currently one of the most significant biological threats to cetaceans worldwide with high infection and mortality rates. CeMV is pleiotropic yet it has special tropism for the respiratory, lymphoid and nervous system and is primarily transmitted by the aerogenous route. A new lineage of CeMV, the Guiana dolphin morbillivirus (GDMV), is known to affect cetaceans off Brazil. GDMV was first detected in a Guiana dolphin (Sotalia guianensis) stranded in the Abrolhos Bank region, in 2010. In addition to pathologic examinations on stranded HW, pathogen survey of free-ranging HW may provide valuable insight into the epidemiology of diseases. We hypothesized that HW in the Brazilian breeding ground could be exposed to CeMV. Thus, in the present study, we investigated the presence of CeMV in exhaled breath condensates (EBC) of HW in the Abrolhos Bank. Overall, 73 samples of EBC from 48 groups of HW were collected during the breeding seasons of 2011 (n = 16) and 2012 (n = 57). One sample failed to have the reference gene amplified and was excluded from the study. CeMV was detected by a RT-qPCR method in 2 EBC samples, representing 2 whale groups. Phylogenetic analysis of partial morbillivirus phosphoprotein gene showed 100% homology to GDMV. Our results show that HW in Brazil are infected by CeMV with a relative prevalence of 4.3% (2/47) and demonstrate the suitability of using EBC and RT-qPCR as a non-invasive tool for CeMV survey in free-ranging whales. This pioneer study provides scientific basis for non-invasive CeMV monitoring of HW, suggests HW may play a role in the dynamics of CeMV and raises concern for potential conservation implications for this species.


Subject(s)
Humpback Whale , Morbillivirus Infections , Morbillivirus , Animals , Morbillivirus/genetics , Morbillivirus Infections/epidemiology , Morbillivirus Infections/veterinary , Phylogeny
13.
Integr Zool ; 16(4): 594-611, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33166068

ABSTRACT

The northern Chilean Patagonia region is a key feeding ground and a nursing habitat in the southern hemisphere for blue whales (Balaenoptera musculus). From 2014 to 2019, during 6 separate research cruises, the dive behavior of 28 individual blue whales was investigated using bio-logging tags (DTAGs), generating ≈190 h of data. Whales dove to significantly greater depths during the day compared to nighttime (day: 32.6 ± 18.7 m; night: 6.2 ± 2.7 m; P < 0.01). During the night, most time was spent close to the surface (86% ± 9.4%; P < 0.01) and at depths of less than 12 m. From 2016 to 2019, active acoustics (scientific echosounders) were used to record prey (euphausiids) density and distribution simultaneously with whale diving data. Tagged whales appeared to perform dives relative to the vertical migration of prey during the day. The association between diurnal prey migration and shallow nighttime dive behavior suggests that blue whales are at increased risk of ship collisions during periods of darkness since the estimated maximum ship draft of vessels operating in the region is also ≈12 m. In recent decades, northern Chilean Patagonia has seen a large increase in marine traffic due to a boom in salmon aquaculture and the passenger ship industry. Vessel strike risks for large whales are likely underestimated in this region. Results reported in this study may be valuable for policy and mitigation decisions regarding conservation of the endangered blue whale.


Subject(s)
Balaenoptera/physiology , Diving , Animals , Behavior, Animal , Chile , Euphausiacea , Feeding Behavior , Remote Sensing Technology , Ships
14.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64: e21200221, 2021. tab, graf
Article in English | LILACS | ID: biblio-1285550

ABSTRACT

HIGHLIGHTS Novel whale optimization algorithm is proposed for prediction of breast cancer. Deep learning-based WOA adjusts the CNN structure as per maximum detection accuracy. Proposed method achieves 92.4% accuracy in comparison to 90.3%. Validity of method is evaluated with magnifying factors like 40x, 100 x, 200x, 400x.


Abstract Breast cancer is one of the most common cancers among women that cause billions of deaths worldwide. Identification of breast cancer often depends on the examination of digital biomedical photography such as the histopathological images of various health professionals, and clinicians. Analyzing histopathological images is a unique task and always requires special knowledge to conclude investigating these types of images. In this paper, a novel efficient technique has been proposed for the detection and prediction of breast cancer at its early stage. Initially, the dataset of images is used to carry out the pre-processing phase, which helps to transform a human pictorial image into a computer photographic image and adjust the parameters appropriate to the Convolutional neural network (CNN) classifier. Afterward, all the transformed images are assigned to the CNN classifier for the training process. CNN classifies incoming breast cancer clinical images as malignant and benign without prior information about the occurrence of cancer. For parameter optimization of CNN, a deep learning-based whale optimization algorithm (WOA) has been proposed which proficiently and automatically adjusts the CNN network structure by maximizing the detection accuracy. We have also compared the obtained accuracy of the proposed algorithm with a standard CNN and other existing classifiers and it is found that the proposed algorithm supersedes the other existing algorithms.


Subject(s)
Humans , Breast Neoplasms/prevention & control , Early Detection of Cancer , Whales , Neural Networks, Computer , Deep Learning
15.
J Comp Pathol ; 181: 26-32, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33288147

ABSTRACT

We provide pathological, immunohistochemical and molecular evidence of cetacean morbillivirus (CeMV) infection in a live-stranded adult female killer whale (Orcinus orca), which stranded alive in Espírito Santo State, Brazil, in 2014. Although attempts were made to release the animal, it stranded again and died. The main pathological findings were severe pulmonary oedema, pleural petechiation, multifocal, lymphoplasmacytic meningoencephalitis and leptomeningomyelitis with perivascular cuffing and gliosis, chronic lymphocytic bronchointerstitial pneumonia and multicentric lymph node and splenic lymphoid depletion. Other pathological findings were associated with the 'live-stranding stress response'. Immunohistochemical analysis revealed multifocal morbilliviral antigen in neurons and astrocytes, and in pneumocytes, histiocytes and leukocytes in the lung. CeMV was detected by a novel reverse transcriptase polymerase chain reaction method in the brain and kidney. Phylogenetic analysis of part of the morbillivirus phosphoprotein gene indicates that the virus is similar to the Guiana dolphin (Sotalia guianensis) morbillivirus strain, known to affect cetaceans along the coast of Brazil. To the authors' knowledge, this is the first report of morbillivirus disease in killer whales.


Subject(s)
Morbillivirus Infections , Morbillivirus , Whale, Killer , Animals , Brazil , Fatal Outcome , Female , Morbillivirus Infections/veterinary , Phylogeny
16.
Mar Environ Res ; 157: 104927, 2020 May.
Article in English | MEDLINE | ID: mdl-32275509

ABSTRACT

Whale watching in Patagonia began in 1973, with the southern right whale (Eubalaena australis) as a target. Thus far, only short-term effects of whale watching on behaviour have been evaluated. The southern right whale population is increasing locally and expanding to adjacent areas. We evaluated boat effects on the biological system through the analysis of breathing rate, linearity, reorientation rate and total distance travelled. Short-term movement patterns of SRW in the area are not severely affected by whale watching operations in Puerto Pirámide at this level of activity. However, significant changes in breathing rates in the presence of boats deserve further attention considering that whales return the same location. In light of the present work, the whales that breed at Península Valdés may be tolerant to whale watching boats.


Subject(s)
Motor Activity , Ships , Whales/physiology , Animals , Argentina , Respiration
17.
Nat Prod Res ; 34(21): 3048-3053, 2020 Nov.
Article in English | MEDLINE | ID: mdl-31084225

ABSTRACT

Volatile and semi-volatile compounds account for the odors, long valued in the perfumery industry, of the natural product, ambergris. Here we demonstrate application of solid phase micro extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) to headspace analysis of the volatiles and semi-volatiles of jetsam ambergris. The samples collected in 2017/2018, ranged from a black, sticky material from New Zealand, likely recently ejected from a sperm whale, to a white solid found on a beach in Chile and radiocarbon-dated previously to be about 1000 years old. The traces of volatile/semi-volatile compounds extracted included, odorous γ-dihydroionone and odor-free pristane (2,6,10,14-tetramethylpentadecane), as the major constituents. The ratios of these to one another and to many other minor constituents, varied, depending on sample color and age.


Subject(s)
Ambergris/chemistry , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Volatile Organic Compounds/analysis , Chile , New Zealand , Odorants/analysis , Terpenes/analysis , Volatile Organic Compounds/chemistry
18.
Conserv Physiol ; 7(1): coz059, 2019.
Article in English | MEDLINE | ID: mdl-31687140

ABSTRACT

Fin whales in the Gulf of California constitute a resident population genetically isolated from the rest of the North Pacific Ocean. Its small population size and the scarce information available about its dynamics in a semi-enclosed sea underline the importance of conducting studies about its reproduction. Given the monsoonal regime that dominates the oceanographic habitat of this region, we hypothesized seasonality in the population's reproductive activity. To test this, we validated and assayed testosterone and progesterone from blubber biopsies of free-ranging individuals. Lactating females exhibited low progesterone concentrations, whereas a group of females of unknown reproductive stage, but with extremely high progesterone concentrations, showed strong evidence of separation and were considered to be likely ovulating or pregnant. A seasonal model of testosterone concentrations showed a high peak during the late summer. This trend was supported by the first documentation of courtship events and by the recording of a female with high progesterone concentration during summer and re-sighted with a calf 1 year later. Therefore, the breeding in this resident population would be seasonal, as it is in migratory baleen whales, but occurring during the summer/autumn, which is the least productive season in the Gulf of California. Our study represents an important input to assist in future management policies of this protected population.

19.
Dis Aquat Organ ; 137(1): 23-31, 2019 Nov 28.
Article in English | MEDLINE | ID: mdl-31777396

ABSTRACT

Southern right whales Eubalaena australis (SRWs) migrate to southern Brazil for breeding and calving from June through November. Overall, there is scarce knowledge on health status and pathologic conditions in SRWs. We report the pathologic and molecular investigation results of 8 SRWs that were necropsied between 2010 and 2017 within a breeding and calving ground in Santa Catarina state, Brazil. The animals were of various ages (7 newborns/calves, 1 adult) and sex (3 females, 5 males). Five whales stranded dead; 3 stranded alive and died shortly after (n = 2) or were euthanized (n = 1). The causes of stranding and/or death were neonatal respiratory distress syndrome with meconium aspiration (n = 3) with concomitant congenital hepatopathy in one of them; trauma of unknown origin (n = 3), infectious renal and lung disease with presumed sepsis (n = 1), and euthanasia (n = 1). Three animals were PCR-positive for cetacean morbillivirus; one of them also had morbilliviral antigen in kidney via immunohistochemical analysis. These results, integrating novel findings and a published report, contribute to the pathology knowledge of this species.


Subject(s)
Communicable Diseases , Meconium Aspiration Syndrome , Animals , Brazil , Cause of Death , Communicable Diseases/veterinary , Female , Male , Meconium Aspiration Syndrome/veterinary , Whales
20.
Zootaxa ; 4664(2): zootaxa.4664.2.4, 2019 Sep 03.
Article in English | MEDLINE | ID: mdl-31716678

ABSTRACT

A new species of Cetopsis is described from Guiana Shield drainages in Guyana and Suriname. The new species is found in the Konawaruk River and tributaries, Essequibo River basin, Guyana, and in the Mauritie Creek, tributary to the Tempati River, upper Commewijne River basin, Suriname. The new taxon can be distinguished from all congeners by a combination of features: dark spots on sides of the body eye-sized or larger, dark, bilobed patch at the base of the caudal fin, absence of a dark humeral spot, absence of dark pigmentation along the fin-membrane posterior to the first dorsal-fin ray, dark pigmentation at the base of the dorsal fin, dark spots extending ventrally to the bases of anal-fin rays, and 41 total vertebrae with 28 caudal vertebrae. Data on internal anatomy of the new species were incorporated into a previously-published phylogenetic analysis and resolves the position of the new species as the sister group of C. motatanensis, from Lago Maracaibo basin. The new Cetopsis is the first species of the genus known to occur exclusively in the Guiana Shield.


Subject(s)
Catfishes , Animals , Guyana , Phylogeny , Rivers , Suriname
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