Interference and economic damage level of alexandergrass in beans as a function of plant density / Interferência e nível de dano econômico de papuã em feijoeiro em função da densidade de plantas

The study of bean sowing density and the level of economic damage (EDL) caused by alexandergrass (Urochloa plantaginea) are important tools for adequately adopting the integrated management of this weed and, thus, producing food with higher quality and less pesticide residue. Therefore, the objective of this work was to evaluate the interference and the level of the economic damage of alexandergrass in competition with the common bean, estimated as a function of sowing densities of the crop and the weed. The bean cultivar IPR Uirapuru was used. The treatments consisted of four bean densities (140,000; 180,000; 220,000 and 260,000 plants ha-1, respectively) and alexandergrass that varied from 0 to the maximum of 104 plants m-2. The experiment was installed in a Red Aluminoferric Latosol, at the experimental area of the Federal University of the Southern Border, campus Erechim/RS, on 10/31/2016. We used the rectangular hyperbola model to describe the relationship between the loss of bean grain yield and the explanatory variables of plant density (DP), soil cover (CS), leaf area (AF) and shoot dry matter (MS). Therefore, the variables CS and DP can be used instead of AF and MS to estimate grain yield losses in common beans. The density of 260,000 plants ha-1of bean showed greater competitiveness with alexandergrass and the highest values of EDLs, justifying the adoption of weed control management at higher densities.

O estudo da densidade de semeadura do feijoeiro e do nível de dano econômico (NDE) ocasionado pelo papuã (Urochloa plantaginea) são ferramentas importantes para a adoção do manejo integrado dessa planta daninha e, assim, produzir um alimento com maior qualidade e menor resíduo de agrotóxico. Diante disso, objetivou-se com o trabalho avaliar a interferência e o nível de dano econômico do papuã em competição com o feijoeiro, estimados em função de densidades de semeadura da cultura e da planta daninha. Os tratamentos foram compostos por densidades do feijoeiro, cultivar IPR Uirapuru (140.000, 180.000, 220.000 e 260.000 plantas ha-1) e do papuã que variaram de 0 até o máximo de 104 plantas m-2. O experimento foi implantado em um Latossolo Vermelho Aluminoférrico típico na área experimental da Universidade Federal da Fronteira Sul, campus Erechim/RS, em 31/10/2016. Para descrever a relação entre a perda de produtividade de grãos do feijoeiro e as variáveis explicativas; densidade de plantas (DP), cobertura do solo (CS), área foliar (AF) e massa seca da parte aérea (MS), usou-se o modelo da hipérbole retangular. As variáveis CS e DP podem ser usadas em substituição a AF e a MS para estimar as perdas de produtividades de grãos do feijoeiro. A densidade de 260.000 plantas ha-1do feijoeiro apresentou maior competitividade com o papuã e os maiores valores de NDEs, justificando aadoção de medidas de controle da planta daninha em densidades mais elevadas.

Impact of alien fishes on the distribution pattern of indigenous freshwater fishes of Punjab, Pakistan / Impacto de peixes invasores no padrão de distribuição de peixes de água doce em Punjab, Paquistão

Pakistan is the country with mega freshwater fish diversity of native and alien species. In the presence of enormous native fishes varies species of exotic fishes have been introduced into the freshwater bodies of Pakistan which are competing with native freshwater fish fauna and making them deprive of food and habitat as well. Intentional or accidental introductions of animals, plants and pathogens away from their native niche is considered as major leading problem for biodiversity of invaded habitat. Three years study (from January 2017 to December 2019) was conducted in freshwater bodies of Province Punjab, Pakistan. Study was designed to know exotic species impacts on the distribution of native species of fishes. During current survey a total of 68 (indigenous and exotic) fish species belonging to 14 families were recorded from head Qadirabad, head Baloki, Islam headworks and Rasul barrage. Statistical analysis showed that Shannon-Wiener diversity index was the highest (1.41) at both Rasul barrage and Islam headworks but, invasive species were present in very less number in these study sites i.e. Oreochromis mozambicus, O. niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenophryngdon idella, Cyprinus carpio and H. molitrix. The diversity index showed that comparatively low diversity was present in both area head Qadirabad (1.30) and head Baloki (1.4) due to high pressure of invasive species. Direct observation of species and statistical analysis showed that aliens’ species produced negative impact on the local fish fauna diversity, evenness, and numbers. It is concluded that many factors are impacts on the diversity of native fishes, but alien (invasive) species also play a major role to reduction of native species, because aliens’ species produce competition for native species. So it is urgent need to analysis the aliens and native food web and roosting sites in Pakistan, in future.

O Paquistão é um país com ampla diversidade de espécies nativas e exóticas de peixes de água doce. Contudo, diversas espécies de peixes exóticos estão sendo introduzidas nos corpos de água doce paquistanês, as quais estão competindo com a fauna nativa de peixes, tornando-os privados de alimento e habitat. A introdução intencional ou acidental de animais, plantas e patógenos fora de seu nicho nativo é considerada o principal problema da biodiversidade do habitat recém-invadido. Assim, foi realizado um estudo de três anos, de janeiro de 2017 a dezembro de 2019, em corpos de água doce na província de Punjab, Paquistão. A pesquisa foi desenvolvida para conhecer os impactos de espécies exóticas na distribuição de espécies nativas de peixes. Durante a pesquisa, foi registrado um total de 68 espécies de peixes (nativas e exóticas), pertencentes a 14 famílias, nas nascentes dos rios Qadirabad, Baloki e Islam e na barragem de Rasul. A análise estatística mostrou que o índice de diversidade de Shannon-Wiener foi mais alto (1,41) na barragem Rasul (RB) e na nascente do rio Islam (IH); e que a maioria das espécies introduzidas estava presente em um número muito menor, isto é, Oreochromis mossambicus, Oreochromis niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenopharyngodon idella, Cyprinus carpio e Hypophthalmichthy smolitrix nessa área de estudo. Por outro lado, o índice Shannon-Wiener mostrou que a diversidade estava baixa nas nascentes dos rios Qadirabad (1,30) e Baloki (1,4) em razão da alta pressão de espécies invasoras. A observação direta das espécies e a análise estatística indicaram que as espécies invasoras produziram impacto negativo na diversidade, uniformidade e números de peixes da fauna local. Conclui-se que muitos fatores impactam na diversidade de peixes nativos, mas as espécies exóticas (invasoras) também desempenham um papel importante na redução das espécies nativas, em razão da competição existente entre elas. Portanto, é [...].

Ecomorphological relations of sympatric juveniles of clupeiformes from a brazilian sandy beach / Relações ecomorfológicas de juvenis simpátricos de clupeiformes de uma praia arenosa brasileira

Surf zones are important for early life stages of several fish species for presenting characteristics such as high phytoplanktonic production, diverse food availability and shelter against predators. The action of waves in this environment provides nutrient cycling and increase the turbidity making surf zones ideal nursery environments for diverse species of fish, including clupeiforms. Clupeiform species have a great ecological and economic value for being abundant fish in tropical sandy beaches surf zones with significant fisheries importance. Studies about their feeding ecology and environment use are relevant, and one of the methods improving this knowledge is the application of ecomorphological analyses, which helps understanding species ecological interactions and their adaptations. In this context, the present study aimed to identify the ecomorphological relations and infer about the feeding ecology of eight sympatric clupeiform species in a Brazilian tropical sandy beach. Ten ecomorphological variables were analyzed of individuals belonging to the species Anchoa tricolor (Spix & Agassiz, 1829), Anchoa januaria (Steindachner, 1879), Anchovia clupeoides (Swainson, 1839), Anchoviella lepidentostole (Fowler, 1911), Lycengraulis grossidens (Spix & Agassiz, 1829), Chirocentrodon bleekerianus (Poey, 1867), Harengula clupeola (Cuvier, 1829) and Opisthonema oglinum (Lesueur, 1818), whose values were employed in a principal component analysis (PCA) with the two first axis explaining 58.92% of the total variance. A high morphological overlap between the species of Engraulidae was observed with the exception of A. clupeoides, which differed from the others for presenting higher values of the compression index and caudal peduncle compression index. The Clupeidae species differed from the other families due to higher values of relative height and relative head length which also showed differences between the species themselves, having H. clupeola presented the highest values of these variables. The representative of Pristigasteridae showed an intermediate overlap between the species of the other families because of its highly compressed body but with low scores of relative height, caudal peduncle relative length and mouth aspect ratio. The morphological differentiation between the families and even between species from the same family indicates niche divergences, showing that besides their phylogenetical proximity there are differences in their ecological interactions which possibly contribute to their coexistence.

Zonas de arrebentação são importantes para os estágios iniciais de várias espécies de peixes por apresentarem características como alta produção fitoplanctônica, disponibilidade alimentar diversificada e abrigo contra predadores. A ação das ondas nestes ambientes proporciona a ciclagem de nutrientes e eleva a turbidez, tornando as zonas de arrebentação ambientes de berçário ideais para diversas espécies de peixes, incluindo os clupeiformes. Espécies de Clupeiformes possuem alto valor ecológico e econômico, por serem peixes abundantes em zonas de arrebentação em praias arenosas tropicais com significativa importância pesqueira. Estudos sobre sua ecologia alimentar e utilização do ambiente são relevantes, e um dos métodos para aprimorar este conhecimento é a aplicação de análises ecomorfológicas, que auxiliam no entendimento das interações ecológicas das espécies e suas adaptações. Nesse contexto, o presente estudo teve como objetivo identificar as relações ecomorfológicas e inferir sobre a ecologia alimentar de oito espécies de clupeiformes simpátricas em uma praia arenosa tropical Brasileira. Foram analisadas dez variáveis ecomorfológicas de indivíduos pertencentes as espécies Anchoa tricolor (Spix & Agassiz, 1829), Anchoa januaria (Steindachner, 1879), Anchovia clupeoides (Swainson, 1839), Anchoviella lepidentostole (Fowler, 1911), Lycengraulis grossidens (Spix & Agassiz, 1829), Chirocentrodon bleekerianus (Poey, 1867), Harengula clupeola (Cuvier, 1829) e Opisthonema oglinum (Lesueur, 1818), cujos valores foram empregados em uma análise de componentes principais (PCA) com os dois primeiros eixos explicando 58,92% da variância total. Uma elevada sobreposição morfológica entre as espécies de Engraulidae foi observada, com exceção de A. clupeoides, que se diferenciou das demais por apresentar maiores valores do índice de compressão e índice de compressão do pedúnculo caudal. As espécies de Clupeidae diferiram das demais famílias devido aos elevados valores de altura relativa e comprimento relativo da cabeça, o que também mostrou diferenças entre as próprias espécies, tendo H. clupeola apresentado maiores valores destas variáveis. O representante de Pristigasteridae apresentou sobreposição intermediária entre as espécies das demais famílias, devido ao seu corpo altamente comprimido, mas com baixos escores de altura relativa, comprimento relativo do pedúnculo e aspecto da boca. A diferenciação morfológica entre as famílias, e até mesmo entre espécies de uma mesma família, indica divergências de nicho, mostrando que apesar de sua proximidade filogenética, existem diferenças em suas interações ecológicas, possivelmente contribuindo para a sua coexistência.

Impact of alien fishes on the distribution pattern of indigenous freshwater fishes of Punjab, Pakistan / Impacto de peixes invasores no padrão de distribuição de peixes de água doce em Punjab, Paquistão

Pakistan is the country with mega freshwater fish diversity of native and alien species. In the presence of enormous native fishes varies species of exotic fishes have been introduced into the freshwater bodies of Pakistan which are competing with native freshwater fish fauna and making them deprive of food and habitat as well. Intentional or accidental introductions of animals, plants and pathogens away from their native niche is considered as major leading problem for biodiversity of invaded habitat. Three years study (from January 2017 to December 2019) was conducted in freshwater bodies of Province Punjab, Pakistan. Study was designed to know exotic species impacts on the distribution of native species of fishes. During current survey a total of 68 (indigenous and exotic) fish species belonging to 14 families were recorded from head Qadirabad, head Baloki, Islam headworks and Rasul barrage. Statistical analysis showed that Shannon-Wiener diversity index was the highest (1.41) at both Rasul barrage and Islam headworks but, invasive species were present in very less number in these study sites i.e. Oreochromis mozambicus, O. niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenophryngdon idella, Cyprinus carpio and H. molitrix. The diversity index showed that comparatively low diversity was present in both area head Qadirabad (1.30) and head Baloki (1.4) due to high pressure of invasive species. Direct observation of species and statistical analysis showed that aliens species produced negative impact on the local fish fauna diversity, evenness, and numbers. It is concluded that many factors are impacts on the diversity of native fishes, but alien (invasive) species also play a major role to reduction of native species, because aliens species produce competition for native species. So it is urgent need to analysis the aliens and native food web and roosting sites in Pakistan, in future.(AU)

O Paquistão é um país com ampla diversidade de espécies nativas e exóticas de peixes de água doce. Contudo, diversas espécies de peixes exóticos estão sendo introduzidas nos corpos de água doce paquistanês, as quais estão competindo com a fauna nativa de peixes, tornando-os privados de alimento e habitat. A introdução intencional ou acidental de animais, plantas e patógenos fora de seu nicho nativo é considerada o principal problema da biodiversidade do habitat recém-invadido. Assim, foi realizado um estudo de três anos, de janeiro de 2017 a dezembro de 2019, em corpos de água doce na província de Punjab, Paquistão. A pesquisa foi desenvolvida para conhecer os impactos de espécies exóticas na distribuição de espécies nativas de peixes. Durante a pesquisa, foi registrado um total de 68 espécies de peixes (nativas e exóticas), pertencentes a 14 famílias, nas nascentes dos rios Qadirabad, Baloki e Islam e na barragem de Rasul. A análise estatística mostrou que o índice de diversidade de Shannon-Wiener foi mais alto (1,41) na barragem Rasul (RB) e na nascente do rio Islam (IH); e que a maioria das espécies introduzidas estava presente em um número muito menor, isto é, Oreochromis mossambicus, Oreochromis niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenopharyngodon idella, Cyprinus carpio e Hypophthalmichthy smolitrix nessa área de estudo. Por outro lado, o índice Shannon-Wiener mostrou que a diversidade estava baixa nas nascentes dos rios Qadirabad (1,30) e Baloki (1,4) em razão da alta pressão de espécies invasoras. A observação direta das espécies e a análise estatística indicaram que as espécies invasoras produziram impacto negativo na diversidade, uniformidade e números de peixes da fauna local. Conclui-se que muitos fatores impactam na diversidade de peixes nativos, mas as espécies exóticas (invasoras) também desempenham um papel importante na redução das espécies nativas, em razão da competição existente entre elas. Portanto, é [...].(AU)

Behavior and reproduction of belida fish (Notopterus notopterus, Pallas1769) in different stocking density and nurtured with different types offeed

Belida fish (Notopterus notopterus, Pallas 1769) is one of Indonesia's endemic fish that has high economic value so that the catch is so high and has begun to decline in population from nature. The purpose of this study was to analyze the behavior and reproduction of belida fish that nurtured with stocking density and different types of feed. This study was conducted from April to June 2018 in the Fish hatchery and Breeding Laboratory of Fisheries and Marine Science Faculty, Riau University. The design used is a randomized complete design with stocking density treatment consisting of 5, 10, and 15 tail/m³ and type of feed consisting of pellet + vitamin E feed and trash fish feed (dumbo catfish cubs). The results showed that the best treatment was in the stocking density of 5 tail/m³ and trash fish feed (dumbo catfish cubs) showed aggressive fish behavior in chasing the feed given, resulting in reproductive value consisting of the fish number of gonad maturity (TKG IV) as many as 5 fishes, gonado somatic index value of 0.58%, the fecundity of 6,053 eggs, egg diameter of 2.49 mm and semen volume of 0.045ml.(AU)

Behavior and reproduction of belida fish (Notopterus notopterus, Pallas1769) in different stocking density and nurtured with different types offeed

Belida fish (Notopterus notopterus, Pallas 1769) is one of Indonesia's endemic fish that has high economic value so that the catch is so high and has begun to decline in population from nature. The purpose of this study was to analyze the behavior and reproduction of belida fish that nurtured with stocking density and different types of feed. This study was conducted from April to June 2018 in the Fish hatchery and Breeding Laboratory of Fisheries and Marine Science Faculty, Riau University. The design used is a randomized complete design with stocking density treatment consisting of 5, 10, and 15 tail/m³ and type of feed consisting of pellet + vitamin E feed and trash fish feed (dumbo catfish cubs). The results showed that the best treatment was in the stocking density of 5 tail/m³ and trash fish feed (dumbo catfish cubs) showed aggressive fish behavior in chasing the feed given, resulting in reproductive value consisting of the fish number of gonad maturity (TKG IV) as many as 5 fishes, gonado somatic index value of 0.58%, the fecundity of 6,053 eggs, egg diameter of 2.49 mm and semen volume of 0.045ml.

Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.

Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.(AU)

Temporal differences in breeding site use between tits and mice

Describing the interactions among cavity breeders is key to understanding their breeding ecology. In this study the temporal difference in cavity use between the great tit, Parus major (Linnaeus, 1758) and the small Japanese field mice, Apodemus argenteus (Temminck, 1845) is investigated, as a first step for clarifying the interaction between bird and mammal cavity breeders. Forty-seven nest boxes were installed on tree trunks in two urban forests of Hokkaido Island, Japan, and the breeding nests of tits and mice were found in 34 and 11 boxes, respectively. The tits used the nest boxes throughout the breeding season, from May to July. In contrast, mice breeding nests were found in the last half of the breeding season, from July to October. Our results showed that field mice rarely used boxes during the tits’ breeding season. This study provides important information, such as temporal differences in breeding site use between tits and mice.

Temporal differences in breeding site use between tits and mice

Describing the interactions among cavity breeders is key to understanding their breeding ecology. In this study the temporal difference in cavity use between the great tit, Parus major (Linnaeus, 1758) and the small Japanese field mice, Apodemus argenteus (Temminck, 1845) is investigated, as a first step for clarifying the interaction between bird and mammal cavity breeders. Forty-seven nest boxes were installed on tree trunks in two urban forests of Hokkaido Island, Japan, and the breeding nests of tits and mice were found in 34 and 11 boxes, respectively. The tits used the nest boxes throughout the breeding season, from May to July. In contrast, mice breeding nests were found in the last half of the breeding season, from July to October. Our results showed that field mice rarely used boxes during the tits breeding season. This study provides important information, such as temporal differences in breeding site use between tits and mice.(AU)

Feeding ecology of Rivulus luelingi (Aplocheiloidei: Rivulidae) in a Coastal Atlantic Rainforest stream, southern Brazil

Feeding habits of the killifish Rivulus luelingi collected in a black water stream of the Coastal Atlantic Rainforest in southern Brazil were investigated. Eight samplings were made between April 2003 and January 2004. The diet, assessed through a similarity matrix with the estimated contribution values of food items, included microcrustaceans, aquatic immature insects (larvae and pupae), aquatic adult insects, terrestrial insects, insect fragments, spiders, and plant fragments. Differences in the diet according to temporal variations (months) were registered, but changes related with size classes evaluated and high/low precipitation period were not observed. The species presented an insectivorous feeding habit, and its diet in the studied stream was composed of autochthonous (mainly aquatic immature insects) and allochthonous (mainly insect fragments) material.(AU)

Neste estudo foram investigados os hábitos alimentares do peixe anual Rivulus luelingi em um riacho de água escura da Floresta Atlântica Costeira do Sul do Brasil. Oito amostragens foram realizadas entre abril de 2003 e janeiro de 2004. A dieta, avaliada através de uma matriz de similaridade com os valores de contribuição estimados para os itens alimentares, inclui microcrustáceos, insetos imaturos aquáticos, insetos aquáticos e terrestres, fragmentos de insetos, aranhas e fragmentos de plantas. Diferenças relacionadas ao período amostral (meses) foram registradas, mas mudanças na dieta em função das classes de tamanho avaliadas e o período de alta/baixa precipitação não foram observadas. A espécie apresentou hábito alimentar insetívoro, e sua dieta no riacho estudado foi composta por itens autóctones (principalmente insetos imaturos aquáticos) e alóctones (principalmente fragmentos de insetos).(AU)