头足类早期生长阶段的比较研究

本文首次系统描述了乌贼科、枪乌贼科、微鳍乌贼科和蛸科(章鱼科)浅海性种类早期生长阶段的形态特征,并与成体的形态特征相比较。对比了浅海性头足类与大洋性头足类的早期生长阶段。发现浅海性头足类在早期生长阶段中的形态变化较小,而大洋性的头足类在早期生长阶段中的形态变化较大。表明在系统演化中,浅海性头足类已走在大洋性头足类的前面。     

头足类神经肽研究进展

神经肽是一类由神经内分泌组织分泌的小分子多肽。近年来随着头足类的经济价值越来越受到人们的重视,其神经肽的研究也日趋深入。通过高效液相色谱分离纯化、质谱鉴定、免疫组化定位和分子克隆等技术方法发现神经肽对头足类的生殖调控等具有重要意义。本文就目前已发现的7类头足类神经肽的种类、分布、结构与功能进行了综述,同时,展示了目前头足类神经肽研究存在的问题,并对头足类神经肽的发展趋势和应用前景进行了展望。     

稳定同位素技术在头足类摄食生态学研究中的应用

头足类在海洋食物网营养关系中占有重要地位,然而对其复杂的生活史过程,尤其是摄食生态学信息仍知之甚少.稳定同位素技术作为传统食物网科学研究方法的有力补充,可更深层次地分析头足类的摄食习性和栖息地等方面的重要信息.本文在比较分析国内外头足类摄食生态学研究方法的基础上,系统归纳总结了稳定同位素技术在头足类摄食生态学研究中的发展现状并介绍最新进展情况,着重分析稳定同位素技术在头足类生活史信息,尤其是在摄食生态学研究中的应用现状及发展前景,包括测定样品标准化、头足类生长发育过程中的食性转换和洄游分布等核心问题,以促进其在头足类生物学研究中的应用.     

《新疆石炭纪头足类》中国古生物志,新乙种,第27号

<正> 本书共分六部分:前言、含头足类地层剖面简介、新疆石炭系简介与含头足类地层的对比、新疆北部泥盆-石炭系的界线、新疆石炭纪头足类动物群的分析、系统描述。新疆的石炭系相当发育、产丰富的头足类,是我国研究石炭纪头足类的重要地区之一。本书系统描述了新疆地区石炭系12个剖面中所产的头足类标本,鹦鹉螺15属21种(含5新种)归10科3目,菊石27属(亚属)75种(含2新属1新亚属27新种)归15科2目。对新疆含头足类的石炭纪地层进行了综合研究,共建立     

中国古生物学会头足类学科组成立大会暨第一届学术会议在无锡召开

中国古生物学会头足类学科组成立大会暨第一届学术会议自4月5日至9日在江苏无锡举行。参加会议的有来自全国科研、地质、煤炭、冶金和大专院校等近50个单位从事头足类研究工作的六十余位会员。这是我国头足类研究工作者空前的盛会,它标志着我国头足类研究工作进入一个新阶段。开幕式由中南矿冶学院区元任教授主持,头足类学科筹     

甘肃宝积山盆地中侏罗世植物群地质时代及植物区系探讨*

湘西–鄂西地区具有中–晚奥陶世连续过渡、出露良好的地层序列, 并产出大量头足类化石。我们选择了位于该地区的湖北宜昌陈家河剖面和湖南桃源茅草铺剖面开展头足类研究工作, 采集化石标本1000余块, 鉴定出了24属46种。本文描述了其中6个新种, 归属于3目3科5属。在中–晚奥陶世头足类动物群研究基础上, 本文在湖北宜昌陈家河剖面宝塔组和临湘组自下而上识别出Sinoceras chinense带和Richardsonoceras simplex带两个头足类化石带; 在湖南桃源茅草铺剖面牯牛潭组、大田坝组和宝塔组下部识别出4个头足类化石带, 自下而上分别是Proterovaginoceras incognitum带、Ancistroceras undulatum带、Cyclolituites带以及Sinoceras chinense带。在此基础上, 结合前人已发表的数据, 本文厘定了中扬子地区牯牛潭组到宝塔组的5个头足类化石带, 自下而上分别是: Proterovaginoceras incognitum带、Meitanoceras-Ancistroceras带、Lituites–Cyclolituites带、Sinoceras chinense 带和Richardsonoceras simplex带, 为该地区生物地层划分对比提供了头足类信息。     

中国古生物学会头足类学科组第三次学术会议简报

中国古生物学会头足类学科组第三次学术会议于1988年4月2日至6日在安徽屯溪召开。来自全国12个省(区)的34位代表出席了会议,代表中大多是科研、教育、生产等部门的中坚力量。会议召开期间,正值中国古生物学会名誉理事、头足类学科组第一届组长、中国头足类学科带头人赵金科教授逝世一周年,为了纪念他对中国头足类学科事业和培养头足类学科人才方面作出的卓越贡献,全体代表在会议开始时向赵金科教授致哀。     

中国古生物学会活动简讯

本文描述了上寒武统凤山组头足类27个种,分属于16个属,5个科。其中2新科,11新属,26新种。除2个种属于原珠角石目外,其余都属于爱丽斯曼角石目。文中对头足类早期阶段(ε_3-0)的系统发生进行了分析研究,编制了系统发生图。并指出我国北方黄河古海盆,不仅是头足类的发源地,而且是头足类早期阶段辐射发展的中心,寒武纪末期一凤山期是头足类发生、发展的很重要的时期;凤山期早期的Plectronoceras 是头足类早期阶段的代表,内角石类,珠角石类,鹦鹉螺类是由它演化而来的。还从头足类演化的角度,讨论了寒武系与奥陶系的分界问题。     

内蒙古桌子山区域奥陶纪头足类化石新材料

内蒙古桌子山区域下奥陶统三道坎组和桌子山组含有丰富的头足类化石。在参考前人研究成果的基础上,对头足类的系统演化,地层分布进行了分析。描述了９属１６种。     

3种经济头足类透明标本的制作方法

近年来,透明鱼类标本的制作技术日臻成熟。以日本枪鱿、无针乌贼及短蛸3种经济头足类为实验材料,借鉴透明鱼类标本制作技术,首次探索了头足类透明标本的制作方法。结果显示:在碱处理前应除去墨汁,避免后期墨囊破裂、墨汁流出污染标本头部;使用了阿利新蓝、甲苯胺蓝、番红O及茜素红4种染色剂,并证明这些染色剂对于头足类透明标本的染色具有良好的效果;标本充分透明后,清晰展现出内脏团、角质颚、海螵蛸等内部结构,为头足类分类鉴定提供了便利;在褪色步骤中,使用甘油、氢氧化钾混合液代替过氧化氢,避免了过氧化氢过度氧化处理标本造成发白起泡现象。     

Experimental fragmentation patterns of modern Nautilus shells and the implications for fossil cephalopod taphonomy

Shells of modern Nautilus pompilius from the Philippines were experimentally fragmented designed to mimic: (1) transport with sediment; (2) sediment loading; and (3) collision during floating. The breaking patterns by other mechanisms (predation and implosion by hydrostatic pressure) documented in the literature were also considered. The breaking patterns produced by various mechanisms are distinct and can therefore be differentiated. The results allow identification of the distinct mechanisms responsible for specific fragmentation not only in modern Nautilus but also in fossil cephalopods. This is a new approach for the more complete recognition of post-mortem transport of fossil cephalopods and their early taphonomic history, and contributes to our understanding of their palaeobiogeography and palaeoecology.     

DIETS OF BAIRD'S BEAKED WHALES, BERARDIUS BAIRDII, IN THE SOUTHERN SEA OF OKHOTSK AND OFF THE PACIFIC COAST OF HONSHU, JAPAN

Stomach contents were analyzed from 127 Baird's beaked whales, Berardius bairdii , taken in coastal waters of Japan. During late July-August of 1985–1987, 1989, and 1991, 107 samples were collected from off the Pacific coast of Honshu. An additional 20 samples were collected from whales taken in the southern Sea of Okhotsk during late August—September of 1988 and 1989. Prey identification using fish otoliths and cephalopod beaks revealed the whales fed primarily on deep-water gadiform fishes and cephalopods in both regions. Prey species diversity and the percentage of cephalopods and fish differed between the two regions. Off the Pacific coast of Honshu the whales fed primarily on benthopelagic fishes (81.8%) and only 18.0% on cephalopods. Eight species of fish representing two families, the codlings (Moridae) and the grenadiers (Macrouridae), collectively made up 81.3% of rhe rotal. Thirty species of cephalopods representing 14 families made up 12.7%. In the southern Sea of Okhotsk, cephalopods accounted for 87.1% of stomach contents. The families Gonatidae and Cranchiidae were the predominant cephalopod prey, accounting for 86.7% of the diet. Gadiform fish accounted for only 12.9% of the diet. Longfin codling, Laemonema longipes , was the dominant fish prey in both regions. Depth distribution of the two commonly consumed fish off the Pacific coast of Honshu indicate the whales in this region fed primarily at depths ranging from 800 to 1,200 m.     

Behavioural relevance of polarization sensitivity as a target detection mechanism in cephalopods and fishes

Aquatic habitats are rich in polarized patterns that could provide valuable information about the environment to an animal with a visual system sensitive to polarization of light. Both cephalopods and fishes have been shown to behaviourally respond to polarized light cues, suggesting that polarization sensitivity (PS) may play a role in improving target detection and/or navigation/orientation. However, while there is general agreement concerning the presence of PS in cephalopods and some fish species, its functional significance remains uncertain. Testing the role of PS in predator or prey detection seems an excellent paradigm with which to study the contribution of PS to the sensory assets of both groups, because such behaviours are critical to survival. We developed a novel experimental set-up to deliver computer-generated, controllable, polarized stimuli to free-swimming cephalopods and fishes with which we tested the behavioural relevance of PS using stimuli that evoke innate responses (such as an escape response from a looming stimulus and a pursuing behaviour of a small prey-like stimulus). We report consistent responses of cephalopods to looming stimuli presented in polarization and luminance contrast; however, none of the fishes tested responded to either the looming or the prey-like stimuli when presented in polarization contrast.     

Cephalopod dynamic camouflage: bridging the continuum between background matching and disruptive coloration

Individual cuttlefish, octopus and squid have the versatile capability to use body patterns for background matching and disruptive coloration. We define—qualitatively and quantitatively—the chief characteristics of the three major body pattern types used for camouflage by cephalopods: uniform and mottle patterns for background matching, and disruptive patterns that primarily enhance disruptiveness but aid background matching as well. There is great variation within each of the three body pattern types, but by defining their chief characteristics we lay the groundwork to test camouflage concepts by correlating background statistics with those of the body pattern. We describe at least three ways in which background matching can be achieved in cephalopods. Disruptive patterns in cuttlefish possess all four of the basic components of ‘disruptiveness’, supporting Cott''s hypotheses, and we provide field examples of disruptive coloration in which the body pattern contrast exceeds that of the immediate surrounds. Based upon laboratory testing as well as thousands of images of camouflaged cephalopods in the field (a sample is provided on a web archive), we note that size, contrast and edges of background objects are key visual cues that guide cephalopod camouflage patterning. Mottle and disruptive patterns are frequently mixed, suggesting that background matching and disruptive mechanisms are often used in the same pattern.     

THE NORMAL OCCURRENCE OF OCTOPAMINE IN NEURAL TISSUES OF THE OCTOPUS AND OTHER CEPHALOPODS

Abstract— An enzymatic assay was used to measure the concentration of octopamine in tissue of cephalopods. The concentration of octopamine varied over a wide range in neural tissues of Octopi and other cephalopods. The administration of reserpine caused a fall in the concentration of octopamine while monoamine oxidase inhibition caused the concentration to rise. After density gradient centrifugation octopamine was found in the same regions of the gradients as were dopamine and noradrenaline. These findings suggest that octopamine may be involved in neuronal function in cephalopods.     

THE DIET OF GALÁPAGOS SPERM WHALES PHYSETER MACROCEPHALUS AS INDICATED BY FECAL SAMPLE ANALYSIS

Fecal samples were collected while following sperm whales ( Physeter macrocephalus ) off the Galápagos Islands, Ecuador. They contained 133 upper beaks and 164 lower beaks of cephalopods. Analysis of the lower beaks suggests that the sperm whales fed primarily on three genera of cephalopods; Histioteutbis (62%), Ancistrocbeirus (16%), and Octopoteutbis (7%). The beak dimensions indicate that the cephalopods ranged in mantle length from 5 to 54 cm and in mass from 12 to 650 g. Fecal samples varied significantly between five study years and over different parts of the study area, but the number of beaks collected per sample did not correlate significantly with defecation rate (a measure of feeding success). Using beak material from fecal samples gives a biased estimate of sperm whale diet, reducing the frequencies of very small and very large cephalopods. However, all other available methods of assessing sperm whale diet also possess biases.     

CEPHALOPODS AND FISH: THE LIMITS OF CONVERGENCE

Resemblances between cephalopods and fish 1. Modern cephalopods (coleoids < 1000 species) resemble modern fish (30,000 species) more closely than any of their ancestors did. They have not been replaced by the more diversified group in geological time. 2. The main body of the article (pp. 245–283) reviews these resemblances. They are to be found at all levels of analysis. 3. Basic physiological mechanisms of molluscs (pp. 262–5) have been incorporated into systems with performances comparable to those of vertebrate systems. For instance the cephalopod locomotory system (pp. 249–56) and hydrostatic control system (pp. 256–60), structurally very different from their fish counterparts, have similar adaptive radiation. 4. Behaviour (p. 278) and growth of the brain (p. 265) are characteristically vertebrate-like. 5. Cephalopods and fish are considered as occupying the same broad adaptive zone though modal differences (pp. 283–5)-in reproductive habits, growth rate and light-dependent behaviour where extraocular photoreceptors appear to be important - mean that they occupy different areas within that zone. (ii) Evolution of convergence 6. Evidence is presented (pp. 287–293) for considering the convergence as due not merely to similar physical demands of the marine environment, but to dynamic interactions between cephalopods and vertebrates from the late Palaeozoic onwards. 7. The convergence was set on its way when the two groups, independently of each other, acquired locomotory methods that allowed them to increase in size. 8. It is argued that reduction and eventually complete loss of the chambered shell (in all but sepiids) was an evolutionary response to the needs of increased mobility and to the need to go deeper as vertebrate predators pushed out into oceanic waters. 9. The ammonites (pp. 291–2) present a partial model of the course that coleoid ancestors may have taken. 10. Coleoids subsequently reinvaded surface and coastal waters, competing successfully in a teleost habitat. Their most striking adaptations are ones that they share with teleosts. 11. Behavioural interactions in a vertebrate-dominated environment have probably been responsible for the vertebrate-type eye of cephalopods (p. 293). 12. The conclusion that the common adaptive zone shared by cephalopods and fish has been achieved by mutual interactions between the two groups evokes no special evolutionary principles. It assumes that all cephalopod species have (at some period of their evolutionary history) been in competition for food with some vertebrate species and that vertebrates are a source of selection pressures - largely operating through visual behaviour - that maintain and promote convergence upon the ‘fish’ modal type. 13. Selection pressures also operate within behaviour space to maintain and promote the special differences that separate any competitively successful species from all others. Coleoids as a group appear to have retained adaptations associated with such molluscan features as high growth rate and rapid turnover of the population. They are still characteristically crepuscular in habits and have extensive vertical mobility.     

Surface-feeding on cephalopods by procellariiform seabirds in the southern Benguela region, South Africa

Cephalopod beaks recovered from stomach samples taken from 14 seabird species in the southern Benguela region off Southern Africa and from one species at Sub-Antarctic Marion Island, were identified as far as possible, counted and the lower rostral lengths (LRLs) measured. Dorsal mantle lengths (DMLs) and body masses of the cephalopods eaten were estimated. The results of analyses by percentage frequency of occurrence and numerical abundance are discussed with reference to present knowledge of the distribution of cephalopods eaten by seabirds in the areas studied. Division of the cephalopod component of seabird diets into species which float, and species which sink, after death indicates that the birds forage on dead or moribund cephalopods on the surface, rather than catching live bioluminescent cephalopods at night.     

Changes in the digestive gland of the loliginid squid Sepioteuthis lessoniana (Lesson 1830) associated with feeding

Changes associated with feeding in the histological and cytological structure of the digestive gland of the loliginid squid Sepioteuthis lessoniana were examined, along with the nature of both the intracellular and extracellular enzymes produced by the gland. The timing of the release of the extracellular enzymes during the digestive cycle was also determined using a quantitative experimental program. Like that of all coleoid cephalopods, the digestive gland was characterised by one type of cell with several functional stages. As is the case for other loliginid squids, however, the digestive cells did not contain the large enzyme-carrying boules that characterise the digestive glands of most cephalopods. Instead, smaller secretory granules were found in the digestive cells and these may be the enzyme carriers. The prominent rough endoplasmic reticulum, large mitochondria and active Golgi complexes present in the digestive cells are characteristic of cephalopods and indicate a high metabolic activity. Like that of other cephalopods, endocytotic absorption of nutrients and intracellular digestion occurs in the digestive gland of this squid. From quantitative and qualitative examinations of structural changes in the digestive gland of S. lessoniana after feeding, a schedule of its function during the course of digestion was proposed. This indicated that digestion was very rapid, being completed in as little as 4 h in S. lessoniana. Extracellular digestive enzymes were only released after the first hour following feeding, which implies that they are stored in the stomach between meals to increase digestive efficiency.