Effects of Sewage Dumping on Macrobenthic Invertebrates in the Jordan Gulf of Aqaba,Red Sea

There are two sewage outfalls along the Jordanian coastline in the Gulf of Aqaba. During 1982 and 1983 a total of 328 core samples (0.01 m² to a depth of 15 cm) were collected from the two outfalls, two control stations which resemble the outfalls in depth and sediment texture, and from two stations 100 m on both sides of each outfall. Faunal analysis revealed that the total number of individuals, number of species, species richness, and faunal similarities of macrobenthic invertebrates were lower at the sewage outfall near the phosphate loading port than the control station during both collections. At the 100 m stations, the numbers of individuals were generally higher than the sewage and control stations. The number of species, however, was highest at the control station and lowest at the sewage outfall. At the other sewage outfall, where the sewage effluent is discharged sporadically, no measurable effects on macrobenthic invertebrates were found.     

Seasonal Variation in Community Structure of Macrobenthic Invertebrates in Sandy Beaches of Jordan Coastline,Gulf of Aqaba,Red Sea

Two Jordanian sandy beaches, one at the northern end and the other at the southern end near the Saudi-Jordanian border, were examined during November 1984 to October 1985. Sediments of the South station were made of coarser sand than the North station. In general, low organic carbon and calcium carbonate levels were found at both stations. A total of 15839 animals representing 45 taxa were collected from both stations. Major differences in community structure were found between the two stations. An average density of 7981/m², 39 taxa. an average diversity value of 1.78 and an evenness of 0.37 were characteristic of the South station. Lower number of taxa (39) and density (818/m²) were found on the North station. However, the average diversity (3.18) and evenness (0.74) were higher. Using the biological index value of MCCLOSKEY (1970), the archiannelid Saccocirrus sp. was the most dominant species at the South station and the bivalve Tellina perna at the North station.     

Seasonal dynamics of phytoplankton in the Gulf of Aqaba,Red Sea

Seawater samples were collected biweekly from the northern Gulf of Aqaba, Red Sea, for Phytoplankton analysis during the period May 1998 to October 1999. Microscopic counts and HPLC methods were employed. Procaryotic and eucaryotic ultraplankton dominated throughout most of the year, with larger nano- and microplankton making up only 5% of the photosynthetic biomass. Moderate seasonal variations in the 0–125 m integrated Chl a contrasted with a pronounced seasonal succession of the major taxonomic groups, reflecting the changes in the density stratification of the water column: Prochlorococcus dominated during the stratified summer period and were almost absent in winter. Chlorophyceae and Cryptophyceae were dominant during winter mixing but scarce or absent during summer. Diatoms and Synechococcus showed sharp and moderate biomass peaks in late winter and spring respectively, but remained at only low Chl a levels for the rest of the year. Chrysophyceae, Prymnesiophyceae and the scarce Dinophyceae showed no clear seasonal distribution pattern. The implications of alternating procaryotic and eucaryote dominated algal communities for the Red Sea pelagic food web are discussed. Electronic Supplementary Material Electronic supplementary material is available for this article at and accessible for authorised users.     

Niche overlap among two species of coral dwelling fishes of the genus Dascyllus (Pomacentridae)

Synopsis The two damselfish, Dascyllus aruanus and D. marginatus are coral-dwelling species, occurring in separate groups or together in the corals Stylophora pistillata and Acropora spp. The two species, however, occur together more frequently than would be expected by chance. The niches of these species overlap in space, time and food. Looking for mechanisms that allow such coexistence, it was found that in such a bispecific group, no difference exists in agonistic acts between intra — or interspecific encounters. This phenomenon seems to be produced by two independent mechanisms — random settling of juveniles from the plankton and predation pressure that strongly limits the re-settling of the fish.     

广东东海岛与硇洲岛海域底栖贝类物种多样性及其地理分布

海洋底栖贝类是海洋底栖动物区系的重要组分之一, 也是影响海洋生态系统和海洋底质环境的关键类群之一。粤西岸段地处南海北部, 海洋底栖贝类物种丰富, 但却是我国海洋底栖贝类区系调查最为缺乏的区域之一, 严重妨碍了我国近海底栖动物地理区系区划工作的开展。东海岛与硇洲岛海域是粤西岸段中底栖贝类历史研究相对较多的地区, 也是揭示南海北部底栖动物地理格局的关键地区。本文基于中山大学地理科学与规划学院2021-2023年间在东海岛与硇洲岛潮间带及近海海域采集的底栖贝类标本的鉴定, 结合中国科学院南海海洋研究所馆藏标本记录及已发表文献中记载物种的整理, 更新了该海域的底栖贝类名录, 并对各物种在东亚大陆近海的地理分布类型进行了分析。本研究共采集贝类标本2,600余号, 分属73科144属207种, 其中38种为东海岛与硇洲岛海域新记录。结合中国科学院南海海洋研究所馆藏标本及历史文献资料记录的物种, 至本研究为止, 东海岛与硇洲岛海域共记录底栖贝类115科330属602种, 为目前南海北部大陆岸段海洋底栖贝类物种数最多的地区。区系成分上, 热带性暖水种占26.2%; 热带-亚热带性暖水种占49.3%; 余下24.4%为广温性种。地理格局上, 有89.0%的种类在海南岛也有分布记录, 80.2%的种类在北部湾也有分布记录, 粤东岸段有分布记录的种类也占80.2%。研究结果表明, 东海岛与硇洲岛海域的底栖贝类区系十分丰富, 热带性特征明显, 且与海南岛的联系最为密切, 在南海北部近海底栖生物地理区划上可考虑同海南岛划入同一生物地理地区。基于本文结果及近年来的南海北部底栖生物相关研究, 我们推测雷州半岛及琼州海峡对南海北部底栖生物扩散及生物地理格局的影响程度很有可能被高估了。本研究丰富了雷州半岛东侧海域的底栖贝类区系, 为开展整个南海北部的底栖生物地理格局与区系区划工作提供了数据支持。     

Dysomma alticorpus,a new species of cutthroat eel from the Gulf of Aqaba,Red Sea (Teleostei: Synaphobranchidae)

The cutthroat eel Dysomma alticorpus n. sp. is described based on a single specimen collected in a trammel net at a depth of 350 m off Eilat, Israel, Gulf of Aqaba, Red Sea. The new species belongs to the Dysomma anguillare species complex, which comprises species possessing a well-developed pectoral fin, intermaxillary teeth, a uniserial row of 7–15 large compound teeth in the lower jaw (which may be followed by a few smaller teeth), and an anteriorly situated anus with the trunk shorter than the head length. It is characterised by a combination of the following characters: origin of the dorsal fin well anterior to the base of the pectoral fin, predorsal length 13.8% TL; preanal length 22.8% TL; three compound teeth on the vomer; head pores: IO 4, SO 3; M 6; POP 0; AD 1, F 0, ST 0; lateral-line pores: predorsal 4, prepectoral 8, preanal 14, total 57–58, the last at the posterior two-thirds of the total length; MVF 7–16–115; total vertebrae 115. Dysomma alticorpus n. sp. is compared with other species of the genus. A revised key to the species of the genera Dysomma and Dysommina is provided.     

潇水河永州零陵段沿岸蝙蝠物种多样性调查

2011年5月—2013年8月对潇水河永州零陵段沿岸蝙蝠物种多样性进行了初步调查.共记录到蝙蝠8种,分属3科5属.从分布型看,东洋型种类占多数(62.5%);从种群数量看,东亚伏翼Pipistrellus abramus与大蹄蝠Hipposideros armiger占优势,斑蝠Scotomanes ornatus数量最为稀少.区域内蝙蝠喜栖于竹丛、树冠、岩壁、洞穴、民居与古建筑等处.上、下游所栖蝙蝠种类存在差异,但均喜好在水体与植被交接处活动而形成活动聚集地,且洞穴冬眠型蝙蝠的年活动周期较房屋冬眠型蝙蝠的短.调查结果增加了对潇水河沿岸蝙蝠生存现状的了解,可为进一步开展蝙蝠研究和保护提供参考.     

中国海域海马的物种多样性、生态特征及保护建议

濒危野生动植物种国际贸易公约(CITES)于2002年将海马属(Hippocampus)所有物种列入附录II进行国际贸易监管。2021年2月, 农业农村部和国家林业和草原局联合公布了调整后的《国家重点保护野生动物名录》, 明确将中国海域海马属所有物种(野外种群)列为国家二级重点保护动物。尽管我国高度重视海马保护工作, 但目前仍缺乏对各海区海马物种多样性以及重要生态学信息的汇总。本文通过文献资料整理, 提供了最新的中国海域分布的16种海马名录, 总结了其分布区域、栖息生境、繁殖特征等生态信息, 并归纳了不同物种的濒危等级和主要威胁因素。在16种海马中, 莫氏海马(H. mohnikei, 又名日本海马)分布范围最为广泛, 从渤海至南海均有出现。台湾、海南、广东、福建及广西沿岸海域的海马物种多样性较高。海马营底层生活, 其栖息生境十分多样化, 包括珊瑚礁、海草床、海藻场、红树林、碎石及砂泥质海床等。目前, 海马野外种群所面临的主要威胁来自于渔业兼捕及栖息地破坏。为更好地保护海马野外种群, 建议管理部门关注海马作为旗舰物种在海洋生态环境保护工作中的影响力, 建立以海马及其栖息生境为主要保护目标的国家级自然保护区或采取其他有效的区域保护措施; 加强海马保护公众宣传, 着力解决海马兼捕问题; 尽快启动全国范围的海马栖息地调查及种群数量评估工作, 识别海马关键栖息地; 提升贸易监管能力, 规范海马利用管理, 建立鉴别野生和养殖海马群体的关键技术, 以期促进对我国海马野外种群的有效保护。     

哀牢山常绿阔叶林树种多样性及空间分布格局

为了探究哀牢山中山湿性常绿阔叶林树种多样性特点及优势种群空间分布特征,2008年,中国科学院西双版纳热带植物园在哀牢山生态站附近的常绿阔叶林建立了一块6 ha的森林动态监测样地,逐一测量并记录了样地中所有胸径(DBH)≥1 cm的树木的胸径,并对其挂牌标记、鉴定和确定坐标位置.应用Ripley's L-Function分析了样地内4个上层优势种的空间分布格局.结果表明,样地内共有DBH≥>1 cm的乔木12,131株,隶属于25科49属68种.样地内硬壳柯(Lithocarpus hancei)的重要值最大,其胸高断面积也最大;其次为变色锥(Castanopsis wattii);排在第三位的为云南连蕊茶(Camellia forrestii),有1,712个个体,是样地内个体数量最多的树种.和同类型森林相比,哀牢山中山湿性常绿阔叶林是多优种类型,物种总数较少,稀有种所占比例也较小.样地内4个上层优势种的小径级个体数量较多,而大径级个体数量较少,而且在空间上呈现互补特征.对样地中符合条件的26个树种(生活史期间的树木株数≥40株)的空间格局进行分析,53个生长时期中有37个表现为集群分布,表明在树种多样性维持方面,密度制约机制町能不是主要因为,生境异质性可能起着重要作用.     

黔金丝猴活动区苔藓植物多样性研究

通过对梵净山东北部岩高坪区域苔藓植物以及对黔金丝猴活动区生境的研究,报道了黔金丝猴活动区苔藓植物46科,85属,249种(含种以下分类单位),其中贵州新记录种5个.从该区苔藓植物的组成看,温带区系成分最为丰富,占整个区系成分的43.32％;不同海拔的森林植被下苔藓植物的分布有明显的差异:阔叶林的苔藓植物多样性最高,竹林...