Food and feeding habits of Octopus insularis in the Veracruz Reef System National Park and confirmation of its presence in the southwest Gulf of Mexico     

Rigoberto Rosas‐Luis  María de Lourdes Jimnez Badillo  Lucia Montoliu‐Elena  Piedad S. Morillo‐Velarde 《Marine Ecology》2019,40(1)

Octopuses are active predators that feed on a wide range of prey including crustaceans, fishes, and mollusks. They are important components of coral reef systems and support local and artisanal fisheries in the Gulf of México. Octopus insularis has been found to be one of the most relevant components in catches from the coral reef system of Veracruz in the southwestern Gulf of Mexico, and its role in the ecosystem requires assessment. To corroborate the morphological identification of O. insularis, six octopuses were identified by genetic methods. And to understand the trophic relationships between this octopus species and its prey, 394 octopuses caught during 2016 and 2017 by an artisanal fleet were sampled and their stomach contents analyzed. Results showed that crustaceans are the most frequently consumed group, with the genera Mithraculus and Etisus being the most important in the diet. Fishes, bivalves, and gastropods were identified as uncommon prey items in the diet. Their presence in the stomachs could be related to the movement of this octopus outside of the coral reef. Considering that our samples were of medium‐ and large‐sized individuals, cannibalism could be discarded for O. insularis in this size range in the Veracruz reef system. These findings suggest a generalist and opportunistic predation of O. insularis on the most abundant and available prey in the study area, namely the crustaceans. These represents an effective transfer of biomass from the low trophic levels to top predators in the coral reef system.  相似文献   

长江口邻近海域浮游植物粒级结构特征及其与环境的响应关系     

李丽  岑竞仪  崔磊  吕颂辉 《海洋学报(英文版)》2019,38(1):151-159

浮游植物的分粒级研究是监测浮游植物特征的重要工具，对于深入了解浮游植物动态的作用也不容忽视。本文的研究目的在于揭示长江口邻近海域春秋季不同粒级的浮游植物分布动态，分析浮游植物粒级结构与环境因素以及浮游动物群落结构的关系。通过2010年春季和秋季对粒径分级叶绿素a浓度的现场调查研究发现：春季，浮游植物主要以微型浮游植物占优势；秋季，微微型浮游植物和微型浮游植物共同占优势。相关分析结果表明，温度和富营养化状况是影响微型和微微型浮游植物对总叶绿素a贡献的重要因素。浮游动物的摄食压力可能对小型浮游植物对总叶绿素a的贡献起着重要的作用。  相似文献   

New insights on the trophic ecology of bathyal communities from the methane seep area off Concepción,Chile (~36° S)     

Germán Zapata‐Hernández  Javier Sellanes  Andrew R. Thurber  Lisa A. Levin  Frédéric Chazalon  Peter Linke 《Marine Ecology》2014,35(1):1-21

Studies of the trophic structure in methane‐seep habitats provide insight into the ecological function of deep‐sea ecosystems. Methane seep biota on the Chilean margin likely represent a novel biogeographic province; however, little is known about the ecology of the seep fauna and particularly their trophic support. The present study, using natural abundance stable isotopes, reveals a complex trophic structure among heterotrophic consumers, with four trophic levels supported by a diversity of food sources at a methane seep area off Concepción, Chile (~36° S). Although methanotrophy, thiotrophy and phototrophy are all identified as carbon fixation mechanisms fueling the food web within this area, most of the analysed species (87.5%) incorporate carbon derived from photosynthesis and a smaller number (12%) use carbon derived from chemosynthesis. Methane‐derived carbon (MDC) incorporation was documented in 22 taxa, including sipunculids, gastropods, polychaetes and echinoderms. In addition, wide trophic niches were detected in suspension‐feeding and deposit‐feeding taxa, possibly associated with the use of organic matter in different stages of degradation (e.g. from fresh to refractory). Estimates of Bayesian standard ellipses area (SEA_B) reveal different isotopic niche breadth in the predator fishes, the Patagonian toothfish Dissostichus eleginoides and the combtooth dogfish Centroscyllium nigrum, suggesting generalist versus specialist feeding behaviors, respectively. Top predators in the ecosystem were the Patagonian toothfish D. eleginoides and the dusky cat shark, Bythaelurus canescens. The blue hake Antimora rostrata also provides a trophic link between the benthic and pelagic systems, with a diet based primarily on pelagic‐derived carrion. These findings can inform accurate ecosystem models, which are critical for effective management and conservation of methane seep and adjacent deep‐sea habitats in the Southeastern Pacific.  相似文献   

Xinghaiornis lini (Aves: Ornithothoraces) from the Early Cretaceous of Liaoning: An Example of Evolutionary Mosaic in Early Birds     

WANG Xuri  Chiappe M. LUIS  TENG Fangfang  JI Qiang 《《地质学报》英文版》2013,87(3):686-689

We describe a new species of Early Cretaceous bird from the Yixian Formation of Liaoning Province. Xinghaiornis lini gen. et sp. nov. is relatively large and characterized by a long, toothless rostrum and an elevated pedal digit I. The design of the skull and feet suggests that this bird was likely a mud-prober. This discovery provides strong support indicating that this avian trophic specialization originated at least 125 million years ago.  相似文献   

大亚湾三种经济贝类的营养生态位及潜在产量评估     

黎辉  何慧  金启增 《热带海洋学报》1999,(4)

通过周年4个季度对大亚湾3种主要经济贝类———珍珠贝Pinctadamartensii,华贵栉孔扇贝Chlamysnobilis　和贻贝Pernaviridis的采样、观测和鉴定,分析它们胃肠物中的食物组成及其季节变化,综合分析了它们的营养生态位。结果显示,3种贝类的食物组成相似,食物中以碎屑、碎片最多,其次是浮游植物,主要包括硅藻、甲藻、金藻和蓝藻,而浮游动物含量最少,偶尔见到原生动物、轮虫、枝角类和桡足类的残体或壳。大亚湾水体的年初级生产力为63万t有机碳,推算出大亚湾生态系统中贝类的最大产量约为1600t·km-2,潜在产量为16—160t·km-2。  相似文献   

Life history of Galaxias divergens (Salmonoidea: Galaxiidae)     

C. L. Hopkins 《新西兰海洋与淡水研究杂志》2013,47(1):41-57

Galaxias divergent Stokell is a small, bottom‐dwelling fish inhabiting streams in the North Island and the northern part of the South Island. Its ecology is similar in many respects to that of G. vulgaris. The fry develop in the same environment as the adults, unlike the sea‐going young of several other Galaxias spec'es. Spawning occurs in spring and summer, and at least some of the fish mature at the beginning of their second year. The maximum age attained seems to be about 3 years, and the fish can reach a length of about 80 mm in this time. The food consists mostly of small benthic invertebrates taken from both the stream bed and the drift fauna.  相似文献   

Nitrogen fixation in polluted intertidal sediments of Waimea Inlet,Nelson     

B. Ben Bohlool 《新西兰海洋与淡水研究杂志》2013,47(3):271-275

Abstract

Nitrogen fixing potential was measured in summer 1975 by acetylene reduction in situ at 5 stations on the intertidal flats of the Waimea Inlet, Nelson, New Zealand, which receive nutrients from several sources. Highest values (644 μmol?m^?2.d^?1) were obtained on sediments near an apple cannery effluent discharge and were linear through at least two tidal cycles. The cannery waste had the highest carbon to nitrogen ratio (10.3 : 1.0) of all the effluents examined and exhibited the highest rate of acetylene reduction (14.0 μmol?_‐l^?1.d^?1). Sizeable populations of the nitrogen fixing bacteria Klebsiella pneumoniae were isolated from the cannery effluent (2 × 10⁴ per millilitre) and also from the mud adjacent to the discharge pipe (5 × 10⁵ per millilitrc). The stimulatory effect of the cannery effluent on nitrogen fixation in the sediment was shown to be restricted to close to the discharge point. Sediments in areas affected by slaughterhouse and sewage effluents exhibited the second and third highest rates of acetylene reduction, (130 &; 28 μmol?m^?2.d^?1 respectively). In both places, the activities were not restricted to the immediate vicinity of the effluent channels. Nitrogen fixation was lowest in sediments fronting a catchment of grazed pasture. Fixation was low also in sediments affected by effluents from the hydraulic debarker of a woodchip mill.  相似文献   

Diet and dietary variation of New Zealand hoki Macruronus novaezelandiae     

AM Connell  J Forman 《新西兰海洋与淡水研究杂志》2013,47(4):289-308

The diet of hoki was determined from examination of stomach contents of 1992 fish of 26–112 cm total length (TL) sampled at depths of 209–904m on Chatham Rise, New Zealand, from summer research trawl surveys and seasonal commercial fishing trawls, during 2004–2008. Prey was predominantly euphausiids, mesopelagic fishes and natant decapods. Multivariate analyses using distance-based linear models, non-parametric multi-dimensional scaling and similarity percentages indicated that the best predictors of diet variability were the position of the fish in relation to the subtropical front (STF), fish size and longitude. Pasiphaeids were more important to the north of the STF, and sternoptychid fishes and euphausiids more important in the STF convergence area. Euphausiids and sternoptychid fishes were important for smaller hoki (26–55 cm TL), myctophid fishes and natant decapods for larger hoki, and macrourids for the largest hoki (>84 cm TL). The longitudinal effect was characterised by pasiphaeids, euphausiids and sternoptychids to the west, and myctophids in the centre of Chatham Rise. Feeding activity was analysed using generalised additive models, and was found to vary with time of day, sample source (research or commercial), longitude, hoki size and depth. The variability in diet suggested hoki forage opportunistically within their preferred habitat and biological limits.  相似文献   

Ecology of rocky reef fish of northeastern New Zealand: 50 years on     

GP Jones 《新西兰海洋与淡水研究杂志》2013,47(3):334-359

Abstract

This review examines the history and current understanding of the ecology of rocky reef fishes in northeastern New Zealand, marking the fiftieth anniversary of the Leigh Marine Laboratory. The cumulative number of publications increased steadily to c. 180 by 2012. Most attention has been on the snapper (Pagrus auratus, f. Sparidae), the largest in size and economically most important species, and on triplefins (Tripterygiidae), the smallest in size and most diverse family. A strong quantitative school emerged in the 1980s, a period when there was little research on temperate reef fishes elsewhere. A ‘bottom-up’ view of the effects of habitat structure on fish emerged, identifying the key roles of depth, topography and macroalgae. By 2000, attention shifted to using marine reserves as laboratories for ecological research. A ‘top-down’ view of fish as predators emerged, documenting cascading effects on prey communities and habitats. The two different viewpoints have not yet been integrated. Research gaps, including population connectivity and climate change, represent major challenges for the next 50 years.  相似文献   

The geographic distribution of Echiura from southern Africa     

《African Journal of Marine Science》2013,35(1):11-21

The echiuran fauna of southern Africa currently comprises two families, four genera and 16 species of which one has recently been described as new to science and four are new records for the region. The taxonomic characters distinguishing the genera are given. The zoogeographic distribution of the southern African species is outlined and discussed. Knowledge of the echiuran fauna is too scanty to throw any light on the division of the coastline into faunistic provinces.  相似文献