首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Cultural competence, a clinical skill to recognise patients' cultural and religious beliefs, is an integral element in patient‐centred medical practice. In the area of death and dying, physicians' understanding of patients' and families' values is essential for the delivery of culturally appropriate care. Dementia is a neurodegenerative condition marked by the decline of cognitive functions. When the condition progresses and deteriorates, patients with advanced dementia often have eating and swallowing problems and are at high risk of developing malnutrition. Enteral tube feeding is a conventional means of providing artificial nutrition and hydration to meet nutritional needs, but its benefits to the frail population are limitedly shown in the clinical evidence. Forgoing tube feeding is ethically challenging when patients are mentally incompetent and in the absence of an advance directive. Unlike some developed countries, like the United States of America, death and dying is a sensitive issue or even a taboo in some cultures in developing countries that forgoing enteral tube feeding is clinically and ethically challenging, such as China and Malaysia. This article in three parts 1) discusses the clinical and ethical issues related to forgoing tube feeding among patients with advanced dementia, 2) describes how Hong Kong Chinese, North American, and Malaysian Islamic cultures respond differently in the decision‐making patterns of forgoing tube feeding for patients with advanced dementia, and 3) reiterates the clinical implications of cultural competence in end‐of‐life care.  相似文献   

2.
Patients with prion diseases can live for long periods of time in a state of akinetic mutism given appropriate management of their symptoms. To study symptom support in these cases, we performed gastrostomies on 3 patients with V180I genetic Creutzfeldt-Jakob disease (CJD) who had become akinetic and mute, and compared them to 14 other similar patients being fed by tube. In the 3 gastrostomy cases, there were no direct complications due to the gastrostomy or tube feeding, nor were there episodes of discontinuation of tube feeding or initiation of continuous drip infusion due to severe complications. Antibiotics were administered for mild infections, a complication of CJD, with 0.2% and 8.8% of the total time after gastrostomy being used for intravenous or transluminal administration, respectively. We compared the present patient series with that of our previous report statistically, and found that patients undergoing gastrostomy required significantly fewer discontinuations of tube feeding than those who did not. No significant difference in antibiotic administration was found between groups, however. It is our conclusion that gastrostomy should be allowed for symptom support in akinetic patients with prion disease, but adequate informed consent must be provided to the patient's family.  相似文献   

3.
OBJECTIVES--To assess the experiences of obstetricians in England and Wales of serum screening for Down''s syndrome. DESIGN--Postal questionnaire survey. SUBJECTS--Questionnaires were sent to all practising obstetricians in England and Wales with nonacademic appointments who had not participated in an earlier (randomly sampled) survey of obstetricians'' attitudes (n = 555). Responses were received from 393 (71%), of which 351 were analysed. The data represent about one third of obstetric consultants in England and Wales. MAIN OUTCOME MEASURES--The extent of use of serum screening for Down''s syndrome, and the problems encountered. RESULTS--Serum screening for Down''s syndrome was being offered on some basis by virtually all obstetricians in the survey. Nearly half the sample said that they did not have adequate resources for counselling all the women to whom screening was offered. Many problems were reported, which in all cases were more common than equivalent problems encountered with serum screening for neural tube defects. Over 80% (289) said that women not understanding the test was a problem. CONCLUSIONS--There is considerable confusion associated with serum screening for Down''s syndrome. The precedent of serum screening for neural tube defects does not seem to have lessened the problems experienced, rather the contrary. Many obstetricians report inadequate resources for counselling, which is consistent with the high prevalence of problems associated with women not understanding the test. There is an urgent need to consider what counselling should consist of and who should undertake it and to ensure that necessary resources are available.  相似文献   

4.
目的:评估深度水解配方奶(eHPF)在不同体重早产儿早期喂养中临床应用效果。方法:选取2017年9月至2018年12月出生的早产儿,分为极低出生体重儿组(体重1000-1500g之间)62例和低出生体重儿(体重1500-2000g之间)100例,每组再随机分为两组,分别予以深度水解蛋白奶(eHPF)和早产儿配方奶(SPF)喂养。极低出生体重儿组于12小时后开始微量喂养,低出生体重儿12小时内适量喂养;极低出生体重儿组深度水解蛋白奶喂养2周后改早产儿奶喂养,低出生体重儿组深度水解蛋白奶1周后改早产儿奶喂养。比较深度水解蛋白奶在不同体重早产儿早期喂养中的临床应用效果,不同体重早产儿恢复出生体重时间、每日体重增长速度、胃管留置时间、完全肠内喂养天数、住院天数、喂养不耐受发生率、宫外发育迟缓发生率及尿素氮、碱性磷酸酶指标。结果:深度水解蛋白喂养组极低出生体重儿/低出生体重儿恢复出生体重天数、完全肠道喂养天数、胃管留置时间、住院天数较早产儿奶喂养组明显缩短(P0.05),每天体重增长优于早产儿组,喂养不耐受、宫外发育迟缓发生率明显低于早产儿组(P0.05),尿素氮、碱性磷酸酶无统计学差异(P0.05)。结论:深度水解蛋白奶用于不同体重早产儿早期喂养效果明显优于早产儿配方奶,其更有助于早产儿的生长发育。  相似文献   

5.
Although people often refer to quality of life and there is a respectable research tradition to establish it, the meaning of the term is unclear. In this article we qualitatively study an intervention of which the quantitative effects are documented as indecisive. We do this in order to learn more about what the meaning of the term quality of life means when it is studied in daily life. With the help of these findings we reflect on the intricacies of objectifying and measuring quality of life using quantitative research designs. Our case is the feeding tube for patients suffering from ALS, a severe motor neuron disease that rapidly and progressively incapacitates patients. We studied how these patients, who lived in the Netherlands, anticipated and lived with a feeding tube in the course of their physical deterioration. Our analysis shows that the quality of life related to the feeding tube has to be understood as a process rather than as an outcome. The feeding tube becomes a different thing as patients move through the various phases of their illness, due to changes in their condition, living circumstances, and concerns and values. There are very different appreciations of the way the feeding tube changes the body’s appearance and feel. Some patients refuse it because they feel it disfigures their body, whereas others are indifferent to its appearance. Our conclusion is that these differences are difficult to grasp with a quantitative study designs because ‘matters of taste’ and values are not distributed in a population in the same ways as physiological responses to medication. Effect studies assume physiological responses to be more or less the same for everyone, with only gradual differences. Our analysis of quality in daily life, however, shows that what a treatment comes to be and how it is valued shows shows generalities for subgroups rather than populations.  相似文献   

6.
The radiation of cichlid fishes in the African great lakes is often described as adaptive, because, at a superficial level, cichlid fishes seem adapted to the ecological niches they occupy. However, adaptedness has rarely been studied. We''ve investigated to what extent island populations of three species of the rock-dwelling genus Neochromis, endemic to Lake Victoria, are adapted anatomically to exploit locally abundant resources. Specifically, we asked whether different resource environments were reflected in differences in the feeding apparatus, both within species and between species. In populations of two specialized biters, the algae scrapers N. rufocaudalis and N. omnicaeruleus, the biting force of the lower jaw increased with increasing amount of items that require biting in the diet. N. greenwoodi is a less specialized biter; we found differences between two populations in the hyoid position and in the premaxilla that enhance suction feeding. These adaptations were related to the amount of items requiring suction. Comparing across three sympatric pairs of species, in each case different diets were reflected in differences in anatomy.  相似文献   

7.
OBJECTIVE--To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding after acute dysphagic stroke. DESIGN--Randomised prospective study of inpatients with acute stroke requiring enteral nutrition. SETTING--One university hospital (Nottingham) and one district general hospital (Derby). SUBJECTS--30 patients with persisting dysphagia at 14 days after acute stroke: 16 patients were randomised to gastrostomy tube feeding and 14 to nasogastric tube feeding. MAIN OUTCOME MEASURES--Six week mortality; amount of feed administered; change in nutritional state; treatment failure; and length of hospital stay. RESULTS--Mortality at 6 weeks was significantly lower in the gastrostomy group with two deaths (12%) compared with eight deaths (57%) in the nasogastric group (P < 0.05). All gastrostomy fed patients (16) received the total prescribed feed whereas 10/14 (71%) of nasogastric patients lost at least one day''s feed. Nasogastric patients received a significantly (P < 0.001) smaller proportion of their prescribed feed (78%; 95% confidence interval 63% to 94%) compared with the gastrostomy group (100%). Patients fed via a gastrostomy tube showed greater improvement in nutritional state, according to several different criteria at six weeks compared with the nasogastric group. In the gastrostomy group the mean albumin concentration increased from 27.1 g/l (24.5 g/l to 29.7 g/l) to 30.1 g/l (28.3 g/l to 31.9 g/l). In contrast, among the nasogastric group there was a reduction from 31.4 g/l (28.6 g/l to 34.2 g/l) to 22.3 g/l (20.7 g/l to 23.9 g/l) (P < 0.003). In addition, there were fewer treatment failures in the gastrostomy group (0/16 versus 3/14). Six patients from the gastrostomy group were discharged from hospital within six weeks of the procedure compared with none from the nasogastric group (P < 0.05). CONCLUSION--This study indicates that early gastrostomy tube feeding is greatly superior to nasogastric tube feeding and should be the nutritional treatment of choice for patients with acute dysphagic stroke.  相似文献   

8.
1. Interactions between below‐ and above‐ground organisms have attracted interest in recent years, but less is known about the effect of root‐feeding nematodes on above‐ground trophic interactions between herbivores and their natural enemies. 2. This study examined whether the presence of the soybean cyst root nematode Heterodera glycines influences the performance of the above‐ground leaf‐chewing tobacco cutworm Spodoptera litura on soybeans, Glycine max, and whether this in turn affects the success of its parasitoid, Meteorus pulchricornis. Using three soybean cultivars that varied in the level of constitutive resistance to the tobacco cutworm, the study determined whether feeding by the nematode altered the developmental and reproductive performances of the caterpillar and its parasitoid. 3. Root feeding by the nematode slowed tobacco cutworm larval development time and reduced adult body weight. Root feeding by the nematode also had a negative effect on the caterpillar's parasitoid, by prolonging development time, decreasing adult body size and reducing fecundity. These effects increased in a linear trend and varied in magnitude depending on levels of soybean constitutive resistance. 4. These findings demonstrate that root feeding by the nematode can prime soybean plants with negative impacts on their herbivore and its parasitoid, and that the impact may vary in magnitude depending on levels of soybean constitutive defence. The results emphasise the need to integrate soybean constitutive and root nematode‐induced defences for a better understanding of below‐ and above‐ground organism interactions, and to allow insights to be gained into the improvement of soybean integrated pest management programmes.  相似文献   

9.
OBJECTIVE--To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia. DESIGN--Randomised 28 day study of inpatients requiring long term enteral nutrition. SETTING--Three Glasgow teaching hospitals. SUBJECTS--40 patients with dysphagia for at least four weeks secondary to neurological disorders: 20 patients (10 women) were randomised to nasogastric feeding and 20 (eight women) to endoscopic gastrostomy. MAIN OUTCOME MEASURES--Treatment failure (blocked or displaced tubes on three or more occasions or refusal to continue treatment); duration of feeding; intake of liquid diets; complications; nutritional status at end of trial. RESULTS--One patient in each group died before starting feeding. Treatment failure occurred in 18 of the 19 nasogastric patients and in none of the gastrostomy group. The mean (SE) duration of feeding for the nasogastric group was 5.2 (1.5) days. No complications occurred in the nasogastric group but three (16%) of the gastrostomy group developed minor problems (aspiration pneumonia (two patients) wound infection (one)). Gastrostomy patients received a significantly greater proportion of their prescribed feed (93% (2%)) compared with the nasogastric group, (55% (4%); p less than 0.001) and also gained significantly more weight after seven days of feeding (1.4 (0.5) kg v 0.6 (0.1) kg; p less than 0.05). Analyses at days 14, 21, and 28 were not possible due to the small numbers remaining in the nasogastric group. CONCLUSION--Percutaneous endoscopic gastrostomy tube feeding is a safe and effective method of providing long term enteral nutrition to patients with neurological dysphagia and offers important advantages over nasogastric tube feeding.  相似文献   

10.
Intraspecific interactions can change from facilitative to competitive depending on the organism''s ontogeny. In plant‐feeding insects, host plant defenses can be strengthened or weakened by insect feeding and can therefore be important for determining whether two insects feeding on the same plant help or harm each other''s fitness. Here, I conducted two experiments looking at the direct effect of a physical seed defense and the role of intraspecific facilitation in reducing the effects of that defense for juveniles of the red‐shouldered soapberry bug. I demonstrate that juveniles are severely inhibited by the tough seed coat of their host plant, leading to high mortality early in development. Adults, in contrast, can create holes through which younger individuals could potentially feed. I manipulated whether or not seeds were fed on by adults on two host plant species: a well‐defended native host and a poorly defended introduced host. Survival in the first week of development was dramatically improved by prior adult feeding, and this facilitation was stronger on the well‐defended host plant. However, the benefits of prior adult feeding ceased after the first week of development and shifted to having a negative effect on survival, development time, and body size. These results indicate that ontogeny is a key factor determining the effects of plant defenses and the strength and direction of intraspecific interactions across multiple host plant species.  相似文献   

11.
B. A. Stein  S. E. Leventhal 《CMAJ》1984,130(5):599-602
The clinical records of 27 adolescent children of physicians who were treated in a psychiatric unit for adolescents were studied. Most of the children had been referred by their physician fathers for evaluation of conduct or mood disorders. These referrals were often the focus of family distress. There appeared to be no typical syndrome presented by physicians'' children. Those treating such patients should be especially sensitive to the possibility that parental denial will increase the patient''s resistance to therapy. Family therapy, an effective treatment for psychologic problems in adolescents, is often avoided by physicians.  相似文献   

12.
Jasmonate-mediated regulation of VOC emission has been extensively investigated in higher plants, however, only little is known about VOC production and its regulation in ferns. Here, we investigate whether the emission of VOCs from bracken fern Pteridium aquilinum is triggered by herbivory and if so - whether it is regulated by the octadecanoid signaling pathway. Interestingly, feeding of both generalist (Spodoptera littoralis) and specialist (Strongylogaster multifasciata) herbivores as well as application of singular and continuous mechanical wounding of fronds induced only very low levels of VOC emission. In contrast, treatment with jasmonic acid (JA) led to the emission of a blend of VOCs that was mainly comprised of terpenoids. Likewise, treatment with the JA precursor 12-oxo-phytodienoic acid (OPDA) and α-linolenic acid also induced VOC emission, albeit to a lower intesity than the JA treatment. Accumulation of endogenous JA was low in mechanically wounded fronds and these levels were unaffected by the application of oral secretions from both generalist or specialist herbivores. The emission of terpenoids upon JA treatment could be blocked with fosmidomycin and mevinolin, which are inhibitors of the MEP- and MVA pathways, respectively. These results indicate that similar to higher plants, terpenoid VOCs are produced via these pathways in bracken fern and that these pathways are JA-responsive. However, the very low amounts of terpenoids released after herbivory or mechanical damage are in stark contrast to what is known from higher plants. We speculate that S. multifasciata and S. littoralis feeding apparently did not induce the threshold levels of JA required for activating the MEP and MVA pathways and the subsequent volatile emission in bracken fern.  相似文献   

13.
Scanning electron microscopy was used to elucidate the morphology and sequential movement of thrips feeding structures in the 2 species, Frankliniella occidentalis and F. schultzei, (Thysanoptera : Thripidae). The mouthcone consists of paired paraglossae, and fringed labral pad, a single, apically fused mandible and a pair of interlocking maxillae. The maxillae are open apically and form a feeding tube. Ten pairs of sensory pegs of 3 distinct morphological types (sensilla basiconica with a cuticular collar, sensilla basiconica without a cuticular collar, and sensilla trichoidea) were found on the paraglossae. The possible function of these sensory structures in host finding and choice are discussed. No structure for rasping the leaf's surface was found on the mouthcone or the ventral surface of the insect. Live specimens were observed feeding through Parafilm on artificial media (sucrose solution) and lettuce leaf tissue. These observations support earlier findings that thrips feed by piercing leaf cells with the mandible and ingesting cell contents through the feeding tube formed by the maxillary stylets. Based on these findings, we suggest that thrips be classified as piercing-sucking rather than rasping-sucking insects.  相似文献   

14.
The Brazilian Federal Senate created a Parliamentary Inquiry Commission (CPI) to investigate the Bolsonaro government's irregularities in the management of the COVID-19 pandemic. One of the cases that drew attention was the research conducted by Prevent Senior, a private health insurance company, on the early treatment of COVID-19. The article analyzes the scientific validity of the research and the ethical problems related to its implementation. It is based on analysis of Prevent Senior's report of the clinical study, the Brazilian and USA clinical trial registries, the Senate's CPI report, and on the information reported by the media. This case of scientific fraud and political-ideological bias exemplifies how Prevent Senior, using a questionable protocol to enhance its reputation and gain government support, was instrumental in building the “early treatment” narrative for COVID-19, and shows how it served as a basis for a government public policy that promoted the use of ineffective drugs.  相似文献   

15.
Orogastric tube feeding is indicated for neonates with impaired ability to ingest and can be administered by intermittent bolus or continuous schedule. Our aim was to determine whether feeding modalities affect muscle protein deposition and to identify mechanisms involved. Neonatal pigs were overnight fasted (FAS) or fed the same amount of food continuously (CON) or intermittently (INT; 7 × 4 h meals) for 29 h. For 8 h, between hours 20 and 28, pigs were infused with [(2)H(5)]phenylalanine and [(2)H(2)]tyrosine, and amino acid (AA) net balances were measured across the hindquarters. Insulin, branched-chain AA, phenylalanine, and tyrosine arterial concentrations and whole body phenylalanine and tyrosine fluxes were greater for INT after the meal than for CON or FAS. The activation of signaling proteins leading to initiation of mRNA translation, including eukaryotic initiation factor (eIF)4E·eIF4G complex formation in muscle, was enhanced by INT compared with CON feeding or FAS. Signaling proteins of protein degradation were not affected by feeding modalities except for microtubule-associated protein light chain 3-II, which was highest in the FAS. Across the hindquarters, AA net removal increased for INT but not for CON or FAS, with protein deposition greater for INT. This was because protein synthesis increased following feeding for INT but remained unchanged for CON and FAS, whereas there was no change in protein degradation across any dietary treatment. These results suggest that muscle protein accretion in neonates is enhanced with intermittent bolus to a greater extent than continuous feeding, mainly by increased protein synthesis.  相似文献   

16.
One hundred medicolegal cases were analysed to obtain quantitative data about diagnoses and the causes of litigation that affect hospital doctors in the National Health Service. Sixteen actions concerned minor problems that are an unavoidable risk of treatment, and 39 were due to natural causes. In other cases it was debatable whether a medical accident or negligence was responsible. At the end of three years 73 actions had been withdrawn, 12 settled out of court, and one lost in court by the plaintiff, and 14 were pending. Of these 14, nine were likely to reach court on charges of negligence. Contributory causes were failure of communication in 27 and matters connected with the patient''s attitude or personality in 20. Because much time and money are spent on cases that should never have started a doctor should sit on the legal aid panel to give advice for medical cases. Also, solicitors should obtain an independent medical opinion when a complaint is first received from a patient. Consent forms should be more informative and give details of what can reasonably be expected from treatment and its possible risks.  相似文献   

17.
MethodsA cross-sectional study interviewing 60 dyads (a person with early dementia and preserved capacity and their family carer) each completing a modified LSPQ. We assessed how closely carers’ choices resembled the PWD’s preferences for treatment in three proposed health states: the here and now; severe stroke with coma; terminal cancer. Agreement between the PWD and their family carer responses was assessed using Kappa and Prevalence-Adjusted Bias-Adjusted Kappa (PABAK) statistics. We examined whether carer burden and distress, and relationship quality, influenced agreement.ResultsIn interviews PWD were able to indicate their treatment preferences across all three scenarios. In the here-and-now most wanted antibiotics (98%), fewer cardio-pulmonary resuscitation (CPR) (50%) and tube feeding (47%). In severe stroke and coma antibiotics remained the more preferred treatment (88%), followed by CPR (57%) and tube feeding (30%). In advanced cancer PWD expressed lower preferences for all treatments (antibiotics 68%; CPR 50%; tube feeding 37%). Carers’ choices were similar to the PWDs’ preferences in the here-and-now (71% (k = 0.03; PABAK = 0.4) with less agreement for future hypothetical health states. In severe stroke and coma carers tended wrongly to suggest that the PWD preferred more intervention (antibiotic, 67%; k = -0.022; PABAK = -0.60; CPR, 73%; k = 0.20; PABAK = -0.20, tube feeding, 66%; k = 0.25; PABAK = -0.12). In advanced cancer the agreement between PWD and carers was low (antibiotics; k = -0.03; PABAK = -0.52; CPR, k = -0.07; PABAK = -0.45; tube feeding; k = 0.20; PABAK = -0.22). However, both PWD and carers showed marked uncertainty about their preferences for end of life treatment choices. Relationship quality, carer distress and burden had no influence on agreement.ConclusionsThis study is the first to have used the LSPQ with PWD in the UK to consider treatment options in hypothetical illness scenarios. Key finding are that family carers had a low to moderate agreement with PWD on preferences for end of life treatment. This underscores how planning for care at the end of life is beset with uncertainty, even when the carer and PWD perceive the care-giving/receiving relationship is good. Families affected by dementia may benefit from early and ongoing practical and emotional support to prepare for potential changes and aid decision making in the context of the realities of care towards the end of life.  相似文献   

18.
Three years'' experience as a doctor taking two clinics a week in an area health authority child health clinic was reviewed. A wide range of clinical conditions was seen, including: problems associated with feeding in breast- and bottle-fed infants; minor developmental abnormalities (mental, behavioural, and physical); surgical and orthopaedic conditions requiring treatment; medical conditions, mainly respiratory and alimentary infections, skin conditions, and problems of over-treatment for minor ailments; and minor genetic abnormalities. Mothers asked for advice on a wide range of topics, risks and benefits of immunisation being the most common. The clinic doctor needs a wide experience in paediatrics to deal with such problems. It is suggested that all lecturers in child health and paediatric and senior registrars should take one clinic a week for six months, and all medical students should attend some clinics as part of their paediatric training. Health visitors have an important role in helping the clinic doctor, but their training should be more realistic and appropriate facilities should be provided to keep them up to date in their work.  相似文献   

19.
OBJECTIVE--To survey patients'' opinions of their experiences in hospital in order to produce data that can help managers and doctors to identify and solve problems. DESIGN--Random sample of 36 NHS hospitals, stratified by size of hospital (number of beds), area (north, midlands, south east, south west), and type of hospital (teaching or non-teaching, trust or directly managed). From each hospital a random sample of, on average, 143 patients was interviewed at home or the place of discharge two to four weeks after discharge by means of a structured questionnaire about their treatment in hospital. SUBJECTS--5150 randomly chosen NHS patients recently discharged from acute hospitals in England. Subjects had been patients on medical and surgical wards apart from paediatric, maternity, psychiatric, and geriatric wards. MAIN OUTCOME MEASURES--Patients'' responses to direct questions about preadmission procedures, admission, communication with staff, physical care, tests and operations, help from staff, pain management, and discharge planning. Patients'' responses to general questions about their degree of satisfaction in hospitals. RESULTS--Problems were reported by patients, particularly with regard to communication with staff (56% (2824/5020) had not been given written or printed information); pain management (33% (1042/3162) of those suffering pain were in pain all or most of the time); and discharge planning (70% (3599/5124) had not been told about warning signs and 62% (3177/5119) had not been told when to resume normal activities). Hospitals failed to reach the standards of the Patient''s Charter--for example, in explaining the treatment proposed and giving patients the option of not taking part in student training. Answers to questions about patient satisfaction were, however, highly positive but of little use to managers. CONCLUSIONS--This survey has highlighted several problems with treatment in NHS hospitals. Asking patients direct questions about what happened rather than how satisfied they were with treatment can elucidate the problems that exist and so enable them to be solved.  相似文献   

20.
Observations are presented on mouthpart functional morphology, and on feeding, grooming and defaecatory behaviour of eight species of corophioid Amphipoda, viz. Corophium bonnellii, Lembos websteri, Aora gracilis, A. spinicornis, Gammaropsis nitida, Ericthonius punctatus, Jassa falcata and J. marmorata. These data are considered in relation to tube structure and amphipod posture in relation to the tube. All these species occupy double-ended cylindreical tubes made from ''amphipod silk'' secreted by the third and fourth preraeopods, incorporating sediment and other debris to varying degrees. Uniquely among this set of species, however, E. punctatus has a tube that is architecturally distinct. It tapers along its length and has a distinctive oblique main entrance at its widest end. This end is used preferentially. The other species studied use either opening with equal facility. Such a feature is adaptive in facilitating deployment of the antennae and shielding the head of E. punctatus.Two groupings of species are propose: group A which feed inside their tube using pleopod-induced through-tube currents, and group B which feed outside or at the entrance to their tube using external water currents. Group A includes C. bonnellii, L. websteri and the Aora species. Group B includes E. punctatus and the Jassa species. Gammaropsis nitida exhibits traits from both groups, adding weight to its perceived status as a genus representative of the stem corophioid. The ischyrocerid habit of externalizing food-gathering may be regarded as the first step along an evolutionary line leading to the rod-building podocerid types and ultimately towards the caprellids. All species examined show a degree of flexibility in their feeding habits which helps to explain the success of this taxon, which has radiated into a great diversity of aquatic biotopes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号