The goatfish Pseudupeneus maculatus and its follower fishes at an oceanic island in the tropical west Atlantic

The influence of a substratum-disturbing forager, the spotted goatfish Pseudupeneus maculatus on the assemblage of its escorting, opportunistic-feeding fishes was examined at Fernando de Noronha Archipelago (tropical west Atlantic). Followers attracted to spotted goatfish foraging singly differed from followers of spotted goatfish foraging in groups in several characteristics. The larger the nuclear fish group, the greater the species richness and number of individuals of followers. Moreover, groups of foraging spotted goatfish attracted herbivores, not recorded for spotted goatfish foraging singly. The size of follower individuals increased with the size and the number of foraging spotted goatfish. The zoobenthivorous habits of the spotted goatfish and its ability to disturb a variety of soft substrata render it an important nuclear fish for several follower species of the reef fish assemblage at Fernando de Noronha.     

辽西半干旱地区春小麦农田水分循环特征的研究

一、研究地区的生态条件概述辽西属暖温带半干旱低山丘陵区,自然条件差,干旱少雨,干燥度为1.2左右,年均降水量为480.1mm,可能蒸散量为551.7mm,水分亏缺严重,而且70—75%的雨水降子6—8月份,春季偏少。舂季气温回升快,风速大,土壤水分蒸发损失严重,因此春旱频繁,并经常     

Isolation,characterisation and antifungal activity of marine actinobacteria from Goa and Kerala,the west coast of India

In total, 53 marine actinobacteria were isolated from the soils of six different locations in Goa and Kerala, on the west coast of India. All the isolates were screened for their antifungal properties against some phytopathogenic fungi by dual culture experiments. Among the 53 actinobacterial isolates, five isolates inhibited the growth of phytopathogens, namely Colletotrichum falcatum, Thielaviopsis paradoxa and Fusarium semitectum. But none of them were effective against Aspergillus niger, Aspergillus candidus and Aspergillus flavus. The antifungal activity of the actinobacteria was tested by food poisoning techniques, using four different concentrations (0.5%, 1.0%, 1.5% and 2.0%) of cell-free culture filtrates, which showed promising activity (almost 100% inhibition) against three pathogenic and one non-pathogenic fungi at 2% extract concentration. A comparison of the antifungal activity of the actinobacteria was also made with three commercial fungicides, namely hexaconazole, thiophanate methyl and propiconazole. The identity of the antagonistic actinobacteria was confirmed based on the morphological, cultural, biochemical, chemo-taxonomical and physiological characteristics. Among 5 antagonistic isolates, three antagonistic isolates were assigned to the genus Streptomyces, Nocardiopsis (1) and Saccharopolyspora (1).     

川西亚高山林线交错带植被凋落物量及养分归还动态

从2006—2008年,研究了川西亚高山林线交错带群落凋落物产量及N、P、K、Ca和Mg主要养分归还动态。结果表明:林线交错带植被凋落物年产量为389.83kg.hm-2.a-1,5种主要养分年归还量总量为15.82kg.hm-2.a-1,归还量排序为Ca>N>K>Mg>P。其中,叶、枝和其他混合杂物分别占凋落物总量的72.2%、17.9%和9.9%,占养分归还总量的87.4%、7.0%和5.6%。凋落物各组分及养分归还月动态均呈单峰曲线型变化,叶高峰期在9月,而枝、杂物则在10月。凋落物养分含量季节动态因不同凋落物组分和养分元素而异。叶凋落物中N、P、K和Mg含量在生长高峰的6、7月较高,而Ca含量较低;枝凋落物各元素含量总体上月变化不显著,其他混合杂物各元素含量6与10月相对较高,其余各月则无显著差异。     

新疆其木干剖面中新世-上新世沉积物粘土矿物特征及其古气候指示意义

为重建新疆其木干地区中新世-上新世古气候,采用X射线衍射、扫描电子显微分析方法,对该区中新世-上新世沉积物中粘土矿物的相对含量、组合类型及显微形貌等进行了研究。结果显示:中新世早期-早中新世中期,沉积物中粘土矿物以伊利石和绿泥石为主,含少量的蒙脱石,表明以干旱气候为特征;晚中新世中期-早中新世晚期,伊利石的相对含量逐渐降低,且含有少量的蒙脱石和高岭石,指示相对温湿的气候条件;中新世晚期的粘土矿物组分与中新世早期相似,以伊利石和绿泥石为主,指示古气候以干旱为主导;晚中新世晚期至上新世伊利石相对含量降低,而蒙脱石和高岭石的相对含量升高,但由于粘土矿物中伊利石、绿泥石的含量仍然较高,指示古气候仍然以干旱为主导,但相对于中新世而言,这段时期为相对湿润期。以上结果表明,新疆其木干地区中新世-上新世古气候以干旱为主,并且气候经历了干旱-相对湿润-干旱-相对湿润的演化过程,但总体而言,本区中新世比上新世要更为干旱。     

Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south‐west Atlantic coast

Aim To produce an inventory of south‐west Atlantic saltmarshes (from latitude 31°48′ S to 43°20′ S) using remotely sensed images and field sampling; to quantify their total area; to describe the biogeographical variation of the main habitats characterized by dominant vascular plants, in relation to major environmental factors; to test the hypothesis of predominance of the reversal pattern in plant distribution (sedges and grasses dominate the lower, regularly inundated zones, while the upper zones are occupied by more halophytic species) previously described; and to compare these south‐west Atlantic saltmarshes with others world‐wide. Location South‐western Atlantic saltmarshes Methods Field samples of dominant emergent plant species positioned by the global positioning system (GPS) were obtained from most coastal saltmarshes (14) between southern Brazil and northern Patagonia, Argentina. Landsat satellite images were obtained and coastal saltmarsh habitats were quantified by supervised classification, utilizing points gathered in the field. Results Three main plant species dominated the low and middle intertidal saltmarsh, Spartina alterniflora Loesel., Spartina densiflora Brong. and Sarcocornia perennis (P. Mill.) A.J. Scott. The total area of the studied coastal saltmarshes was 2133 km², comprising 380 km² of Sp. alterniflora marsh, 366 km² of Sp. densiflora marsh, 746 km² of Sar. perennis marsh and 641 km² of brackish marsh (dominated by Juncus acutus L., Juncus kraussii Hochst., Scirpus maritimus L., Scirpus americanus Pers. and Phragmites australis (Cav.) Trin.). Cluster analysis showed three habitat types: saltmarshes dominated by (1) Sp. densiflora and brackish species,(2) Sp. alterniflora and Sar. perennis and (3) Sp.densiflora only. The analysis of abiotic variables showed significant differences between groups of habitats and coordinated gradients of the abiotic variables. The south‐west Atlantic coast showed decreasing mean annual rainfall (1200 to 196 mm) and increasing mean tidal amplitude (< 0.5 to > 2.5 m) from latitude 31° to 43°. Main conclusions South‐west Atlantic saltmarshes are globally important by virtue of their total extent. Remote sensing showed that the reversal pattern in plant distribution is not widespread. Indeed, south‐west Atlantic saltmarshes are better characterized by the presence of the halophytic genera Spartina and Sarcocornia. Our results support the interpretation that south‐west Atlantic saltmarshes constitute a class of temperate type (sensu Adam, 1990 ) with transitional characteristics between Australasian–South African saltmarshes and west Atlantic saltmarshes.     

Fossil juvenile coelacanths from the Devonian of South Africa shed light on the order of character acquisition in actinistians

A new coelacanth genus from the Famennian (Upper Devonian) of South Africa is described, principally from presumed juveniles. S erenichthys kowiensis gen. et sp. nov. uniquely shares with Diplocercides a ventral expansion of the elbow‐like lachrymojugal, as well as a symmetrical diphycercal tail supported by expanded neural and haemal spines and radials. Serenichthys is distinguished from Diplocercides by a number of derived characters, including possession of longer anterior parietals, a more crescent‐shaped postorbital with a more anteriorly positioned infraorbital canal, and a far smaller squamosal, which is well separated from the skull roof. By contrast, Serenichthys appears to lacks a second dorsal fin lobe, a derived feature present in Diplocercides. Most specimens of Serenichthys are between 3 and 6 cm in length. They have large eyes, and dermal bones of the skull ornamented with long wavy ridges, similar to the dermal ornament of other Devonian coelacanths such as Gavinia. Larger isolated operculae also collected from the Waterloo Farm locality and attributed to Serenichthys indicate that with growth the ridges on the dermal bones transformed into elongate tubercles, reminiscent of those of Diplocercides and Carboniferous taxa. Phylogenetic analysis resolves Serenichthys as the sister group of Holopterygius and all known post‐Devonian coelacanths. The clade including the unusual leaf‐shaped coelacanths, the Devonian Holopterygius and Carboniferous Allenypterus, branches from the coelacanth lineage immediately crownward of Serenichthys. The presence of abundant juveniles within an estuarine setting strongly parallels the discovery of similarly sized juveniles of Rhabdoderma exiguus together with eggs and yolk‐sack larvae in the Upper Carboniferous Mazon Creek biota. It is therefore argued that Serenichthys, like Rhabdoderma, was using the sheltered estuarine environment as a nursery. © 2015 The Linnean Society of London     

徐闻西岸造礁石珊瑚的组成及空间分布

2008年5-6月在徐闻西岸设置了25个站点,运用截线样带法调查了造礁石珊瑚的种类多样性和空间分布.本次研究共发现造礁石珊瑚57种,每个站位的种类数均不超过30种.Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为1.79和0.42.二异角孔珊瑚(Goniopora duofasciata)、盾形...     

Harbour porpoises respond to climate change

The effects of climate change on marine ecosystems and in particular on marine top predators are difficult to assess due to, among other things, spatial variability, and lack of clear delineation of marine habitats. The banks of West Greenland are located in a climate sensitive area and are likely to elicit pronounced responses to oceanographic changes in the North Atlantic. The recent increase in sea temperatures on the banks of West Greenland has had cascading effects on sea ice coverage, residency of top predators, and abundance of important prey species like Atlantic cod (Gadus morhua). Here, we report on the response of one of the top predators in West Greenland; the harbour porpoise (Phocoena phocoena). The porpoises depend on locating high densities of prey species with high nutritive value and they have apparently responded to the general warming on the banks of West Greenland by longer residence times, increased consumption of Atlantic cod resulting in improved body condition in the form of larger fat deposits in blubber, compared to the situation during a cold period in the 1990s. This is one of the few examples of a measurable effect of climate change on a marine mammal population.