Invertebrate Biology Research Articles

Daphnia as a model organism in limnology and aquatic biology: some aspects of its reproduction and development

Invertebrates comprise the overwhelming majority of all animal species - around 95% of described species, not including substantial cryptic variation. As it is an extremely diverse and heterogeneous group, research on various invertebrate taxa often follows parallel trajectories, with little interaction among experts on different groups. To promote sharing of knowledge within as well as across taxa, the International Society of Invertebrate Reproduction and Development (ISIRD) was established in 1975 in Calicut, India. Since that time, the ISIRD has organised international conferences at three-year intervals where various aspects of invertebrate biology are presented and discussed, naturally with the focus on reproduction and development. Traditionally, marine invertebrate groups have been well represented at all ISIRD congresses, but freshwater invertebrates have often been relatively overlooked at these meetings. The 12th ISIRD congress took place between August 16 and 20, 2010 in Prague, the Czech Republic. Several different Czech institutions collaborated on the organisation of this meeting. As aquatic invertebrate research has a long tradition in the country, we decided to include a section dedicated to popular model organisms in aquatic ecology and evolutionary biology, the "water fleas", cladocerans of the genus Daphnia. The section entitled "Daphnia and other cladocerans as model organisms" was open to any aspects of cladoceran biology directly or indirectly related to their reproduction or development. Unfortunately, the timing of the Prague congress completely overlapped the triennial congress of the International Society of Theoretical and Applied Limnology (SIL) in Cape Town, South Africa. This large meeting in a very attractive setting attracted many cladocerologists from all over the world, including Europe. Therefore, the Daphnia section of the Prague ISIRD meeting remained moderate in size, attracting 13 contributions (eight talks and five poster presentations). The presenting authors mostly originated from Central European countries (the Czech Republic, Poland, Germany, and Austria) but the conference also attracted a visitor from overseas (Mexico). Although the section was small, some of the presentations evoked considerable interest among conference participants working on marine crustaceans. Information exchange between marine and freshwater biologists was promoted, and will hopefully persist at future ISIRD meetings. The contributions presented in the session covered a very wide range of topics, such as the interplay of sexual and asexual reproduction and its impact on seasonal population development and its clonal structure, the impact of major environmental disturbances (floods) on the status of Daphnia diapausing egg banks, factors promoting male production, the importance of Daphnia ageing, the effect of cyanobacteria on Daphnia growth, and the formation of antipredator morphological structures under different conditions. In this special insert, we present five papers from authors that attended the ISIRD meeting, from one German, two Czech, and two Polish teams.

The influence of chronic eicosanoid biosynthesis inhibition on life history of the greater waxmoth, Galleria mellonella and its ectoparasitoid, Bracon hebetor

Eicosanoids are oxygenated metabolites of three C20 polyunsaturated fatty acids, mainly arachidonic acid (AA; 20:4n-6), but also 20:3n-6 and 20:5n-3. Aside from their importance in biomedicine, eicosanoids act in invertebrate biology. Prostaglandins (PGs) influence salt and water transport physiology in insect rectal epithelia and in Malpighian tubules. PGs also influence a few insect behaviors, including releasing oviposition behavior and behavioral fever. Eicosanoids act in ovarian development and in insect immunity. Because eicosanoids act in several areas of insect biology, we posed the hypothesis that chronic inhibition of eicosanoid biosynthesis, in the absence of microbial challenge, can influence insect life table parameters, including developmental time, survival, adult longevity and parasitoid fecundity. Here we report that inhibiting eicosanoid biosynthesis throughout the larval life exerted minor influences on some life table parameters of the greater wax moth, Galleria mellonella and its ectoparasitoid, Bracon hebetor, however, the inhibitors strongly reduced the production and hatchability of the parasitoids’ eggs. The significance of the work relates to the potentials of understanding and targeting eicosanoid systems as a platform for developing new technologies of insect pest management. As seen here, the impact of targeting eicosanoid systems is seen in crucial moments of insect life histories, such as reproduction or immune challenge rather than in overall larval development.

Bones as biofuel: a review of whale bone composition with implications for deep-sea biology and palaeoanthropology

Whales are unique among vertebrates because of the enormous oil reserves held in their soft tissue and bone. These 'biofuel' stores have been used by humans from prehistoric times to more recent industrial-scale whaling. Deep-sea biologists have now discovered that the oily bones of dead whales on the seabed are also used by specialist and generalist scavenging communities, including many unique organisms recently described as new to science. In the context of both cetacean and deep-sea invertebrate biology, we review scientific knowledge on the oil content of bone from several of the great whale species: Balaenoptera musculus, Balaenoptera physalus, Balaenoptera borealis, Megaptera novaeangliae, Eschrichtius robustus, Physeter macrocephalus and the striped dolphin, Stenella coeruleoalba. We show that data collected by scientists over 50 years ago during the heyday of industrial whaling explain several interesting phenomena with regard to the decay of whale remains. Variations in the lipid content of bones from different parts of a whale correspond closely with recently observed differences in the taphonomy of deep-sea whale carcasses and observed biases in the frequency of whale bones at archaeological sites.

About the Cover.

Next article FreeAbout the CoverPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreCover“Who is nibbling at my little house?” The old witch in the fairy tale “Hänsel und Gretel” had reason to be concerned because if the nibbling had continued, over time the house would have experienced serious damage. The lesson could be to not build your house out of food. However, this is exactly what many marine invertebrates do. How do they manage to maintain the integrity of the house while at the same time satisfying their food requirements? This is the question that Osvaldo Cerda and co-authors investigated in their study (pp. 248–258) on the nest-building habits of the marine amphipod Peramphithoe femorata.Amphipods from the family Ampithoidae make nests on algae by gluing together algal pieces or curling up kelp blades. The kelp curler Peramphithoe femorata, a common inhabitant of kelp forests in the SE Pacific, curls up blades of the giant kelp Macrocystis pyrifera. Spinning self-produced silk threads between the two sides of the kelp blades, these amphipods double over the blade and construct a closed, tube-like nest within a few hours (*for short videos of nest-building, see BEDIM, 2010). The amphipods feed on the blade tissues inside their nests, and females, as seen on the cover, share nests with their small offspring.How do these amphipods avoid eating themselves out of house and home? Carefully observing the amphipods in their nests, Cerda et al. noticed that nests are continuously renovated in fine-tuned synchrony with the growth dynamics of the kelp blades. A blade grows from its basis outward—that is, toward the tip. An amphipod, in turn, starts its nest near the tip of the blade and expands it toward the blade basis while feeding on the nest walls. Thus, the nest is not static, but a dynamic structure that steadily moves against the growing blade like a running conveyor belt. The authors suggest that this continuous nest renovation allows amphipods to remain for prolonged periods in a safe (and tasty) home. Nevertheless, aging kelp blades stop growing, forcing the amphipods to move on and start a new nest, most likely on young and growing blades.Credits: Cover photo and layout, Iván A. Hinojosa (Universidad Católica del Norte, Coquimbo, Chile).* BEDIM (Biology, Ecology & Diversity of Invertebrates from Marine Environment). 2010. Nest-building behavior by the amphipod Peramphithoe femorata on the kelp Macrocystis pyrifera. [Online] Available: http://www.bedim.cl/videos.htm [2010, 20 May]. Next article DetailsFiguresReferencesCited by The Biological Bulletin Volume 218, Number 3June 2010 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.1086/BBLv218n3cover Views: 204Total views on this site © 2010 by Marine Biological Laboratory. All rights reserved.PDF download Crossref reports no articles citing this article.

Taxonomy and systematics: contributions to benthology andJ-NABS

AbstractSystematics, or taxonomy, is the study of the diversity of life on Earth. Its goals are to discover and describe new biological diversity and to understand its evolutionary and biogeographic origins and relationships. Here we review the contributions to the field of systematics and taxonomy published over the last 25 y in J-NABS and its predecessor Freshwater Invertebrate Biology (FIB). We examined a total of 64 studies that we considered to be largely taxonomic in nature. We classified these studies into 2 major categories: morphological (e.g., descriptive taxonomy, taxonomic revisions) and molecular (e.g., deoxyribonucleic acid [DNA] barcoding, population genetics). We examined studies in 5-y increments for J-NABS. We also studied the period 1982 to 1985, during which FIB was published. On average, 12 taxonomic studies were published within each 5-y period. Molecular studies first appeared in 1986 and have slowly increased, reaching their greatest number within the last 5 y. Studies also were cl...

Repositioning of an existing drug for the neglected tropical disease Onchocerciasis

Onchocerciasis, or river blindness, is a neglected tropical disease caused by the filarial nematode Onchocerca volvulus that affects more than 37 million people, mainly in third world countries. Currently, the only approved drug available for mass treatment is ivermectin, however, drug resistance is beginning to emerge, thus, new therapeutic targets and agents are desperately needed to treat and cure this devastating disease. Chitin metabolism plays a central role in invertebrate biology due to the critical structural function of chitin for the organism. Taken together with its absence in mammals, targeting chitin is an appealing therapeutic avenue. Importantly, the chitinase OvCHT1 from O. volvulus was recently discovered, however, its exact role in the worm's metabolism remains unknown. A screening effort against OvCHT1 was conducted using the Johns Hopkins Clinical Compound Library that contains over 1,500 existing drugs. Closantel, a veterinary anthelmintic with known proton ionophore activities, was identified as a potent and specific inhibitor of filarial chitinases, an activity not previously reported for this compound. Notably, closantel was found also to completely inhibit molting of O. volvulus infective L3 stage larvae. Closantel appears to target two important biochemical processes essential to filarial parasites. To begin to unravel closantel's effects, a retro-fragment-based study was used to define structural elements critical for closantel's chitinase inhibitor function. As resources towards the development of new agents that target neglected tropical diseases are scant, the finding of an existing drug with impact against O. volvulus provides promise in the hunt for new therapies against river blindness.

BRIDGES: evolution of basic and applied linkages in benthic science

AbstractGrowing awareness of environmental degradation resulted in stricter environmental regulations and laws for aquatic ecosystems. These regulations were followed by an increase in applied research and monitoring beginning in the early 1970s. The number of applied scientists who were members of the North American Benthological Society grew at a commensurate rate. The editors of J-NABS recognized that, despite these increases, submitted manuscripts mostly addressed basic science. In response, the BRIDGES section of J-NABS was created in 1994 to provide a forum for linking basic ecological principles to applied science problems and issues. We examined the emergence of applied science topics in J-NABS and its predecessor, Freshwater Invertebrate Biology, from their beginning in 1982 to 2009. We classified papers among 11 categories that included a basic/applied science linkage. In the 1980s, applied papers were predominantly on effects of eutrophication/pollution and landuse changes. When BRIDGES was est...

OPORTUNIDADES DE INVESTIGACIÓN EN HELMINTOLOGÍA EN PERÚ: MI PROPIA EXPERIENCIA

As a professor of Parasitology and Invertebrate Biology at a small, private liberal arts college in the United States, where I study the transmission ecology of trematode parasites, to date my research experience studying helminths in the Neotropical region has been limited. Of course, many parasitologists in North America and elsewhere have relatively limited exposure to neotropical helminthology beyond textbooks and the primary literature; however, based on my own experience over the last year I believe there exists great opportunity for this to change. The potential for wonderful and productive collaborations continues to increase with greater ease of travel and levels of cooperation and information-sharing. So, while by definition my own experience in Peru is unique to me, I hope that it highlights some of the opportunities for research in helminthology in Peru and thus encourages additional collaborations in the future.

How to Build a “Monster” from Miscellany

How to Build a “Monster” from Miscellany

Target of Rapamycin (TOR) Mediates the Transduction of Nutritional Signals into Juvenile Hormone Production

Anautogeny is a reproductive strategy by which females do not reproduce until they feed. Therefore, nutritional signals must inform the reproductive tissues, and cells that the organism has reached a nutritional status suitable for triggering reproductive processes. One of the possible pathways involved in anautogeny is the "target of rapamycin" (TOR) pathway, which has been described as connecting the nutritional status with growth, proliferation, and cancer. The German cockroach, Blattella germanica, is an anautogenous species whose vitellogenesis is governed by juvenile hormone. In the present report, we describe the cloning of TOR cDNA from B. germanica (BgTOR). Expression studies showed that BgTOR is expressed in adult female corpora allata and fat body. BgTOR knockdown using systemic RNAi in vivo produced a severe inhibition of juvenile hormone synthesis in adult female corpora allata, together with a reduction of mRNA levels corresponding to 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase-1, HMG-CoA synthase-2, and HMG-CoA reductase. In addition, there was a reduction of vitellogenin mRNA in the fat body, and ovaries did not grow. Analysis of TOR expression in corpora allata of fed and starved females suggested that TOR is not regulated at the transcriptional level. Nevertheless, there was a reduction in HMG-CoA synthases and reductase mRNA in corpora allata (but not in the fat body) of starved females, together with a dramatic reduction of juvenile hormone production and ovary development. Taken together, our results indicate that TOR knockdown mimics starvation in terms of corpora allata activity, and suggest that nutritional signals that activate juvenile hormone biosynthesis and vitellogenin production are mediated by the TOR pathway.

A review of subtidal benthic habitats and invertebrate biota of the Strait of Georgia, British Columbia

The initial phase of a collaborative ambient monitoring program (AMP) for the Strait of Georgia (SoG) (Marine Environmental Research, in press.) has focused on the benthos, sedimentary regimes, organic and contaminant cycling in subtidal regions of the strait. As part of that project, we review the primarily subtidal benthic invertebrate faunal communities found in the SoG, with particular reference to habitats and sediment conditions. This topic has not been addressed in the primary literature for over 20 years. Benthic biota are the baseline sentinels of the influence of natural and anthropogenic inputs to sediments. They are also a fundamental component of the food chain at the seafloor, and their community ecology must be clearly understood in order to predict how anthropogenic activities and climate change will affect our coastal oceans. The purpose of this review is to provide context on habitats and biota in the SoG, and to highlight topics and geographic areas where our knowledge of the benthos is limited or lacking.

Invertebrate Biology, Vol. 126, 2007 Author Index

Invertebrate BiologyVolume 126, Issue 4 p. 397-397 Invertebrate Biology, Vol. 126, 2007 Author Index First published: 11 December 2007 https://doi.org/10.1111/j.1744-7410.2007.00116.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume126, Issue4Fall 2007Pages 397-397 RelatedInformation

Microscopy and Microanalysis in Marine Invertebrate Biology

Microscopy and Microanalysis in Marine Invertebrate Biology

Guanine nucleotide exchange factors of the cytohesin family and their roles in signal transduction

Members of the cytohesin protein family, a group of guanine nucleotide exchange factors for adenosine diphosphate ribosylation factor (ARF) guanosine triphosphatases, have recently emerged as important regulators of signal transduction in vertebrate and invertebrate biology. These proteins share a modular domain structure, comprising carboxy-terminal membrane recruitment elements, a Sec7 homology effector domain, and an amino-terminal coiled-coil domain that serve as a platform for their integration into larger signaling complexes. Although these proteins have a highly similar overall build, their individual biological functions appear to be at least partly specific. Cytohesin-1 had been identified as a regulator of beta2 integrin inside-out regulation in immune cells and was subsequently shown to be involved in mitogen-associated protein kinase signaling in tumor cell proliferation as well as in T-helper cell activation and differentiation. Cytohesin-3, which had been discovered to be strongly associated with T-cell anergy, was very recently described as an essential component of insulin signal transduction in Drosophila and in human and murine liver cells. Future work will aim to dissect the mechanistic details of the modes of action of the cytohesins as well as to define the precise roles of these versatile proteins in vertebrates at the genetic level.

Small is useful in endocrine disrupter assessment—four key recommendations for aquatic invertebrate research

As we enter the 21st "biocentury", with issues such as biodiversity and biotechnology growing in public profile, it is important to reflect on the immense ecological, medical and economic importance of invertebrates. Efforts to understand the diverse biology of invertebrates come from many directions, including Nobel Prize winning developmental biology, research to control insects that threaten human health and food supplies, aquaculture opportunities and also within ecotoxicology. In the latter context, this special journal volume highlights the importance of addressing endocrine disruption in aquatic invertebrates, from molecular and cellular biomarkers to population-relevant adverse effects. The contributors to this special volume have provided an excellent assessment of both the fundamental endocrinology and applied ecotoxicology of many aquatic invertebrate groups. On the premise that reproductive success is ultimately the vital population parameter, this chapter gives a personal view of key gaps in knowledge in invertebrate reproductive and developmental endocrinology and ecotoxicology. Based on current knowledge, there are four key issues that need to be prioritised within aquatic ecotoxicology: (1) a wider assessment of the reproductive status of invertebrates in both freshwater and coastal ecosystems; (2) prioritisation of laboratory studies in OECD and other regulatory test organisms, including basic endocrinology and ADME (absorption, distribution, metabolism and excretion) research; (3) development and validation of mechanistic biomarkers that can be used as "signposts" to help prioritise species and chronic test endpoint selection, and help link data from laboratory and field studies; and (4) develop a comparative invertebrate toxicology database utilising the prioritised reference chemicals from the EDIETA workshop, encompassing the diverse modes-of-action pertinent to endocrine disrupter testing in both aquatic arthropod and non-arthropod invertebrates.

Parsimony analysis of endemicity of enchodontoid fishes from the Cenomanian

Parsimony analysis of endemicity was applied to analyze the distribution of enchodontoid fishes occurring strictly in the Cenomanian. The analysis was carried out using the computer program PAUP* 4.0b10, based on a data matrix built with 17 taxa and 12 areas. The rooting was made on an hypothetical all-zero outgroup. Applying the exact algorithm branch and bound, 47 trees were obtained with 26 steps, a consistency index of 0.73, and a retention index of 0.50. The topology found with a majority rule consensus was: ((Mexico) + (United States) + (Morocco + Italy) + (Lebanon + Israel) + (Italy-Slovenia) + (Brazil)) + (D.R. Congo) + (Sweden) + (Germany) + (England). The procedure delimited two areas of endemism in the Tethys Ocean. They are Morocco and southern Italy and Lebanon and Israel. The area of endemism formed by Morocco + Italy represents the North African region of the Tethys Ocean, and that formed by Lebanon + Israel is in the mid-Tethyan Ocean. Our results are in partial agreement with the patterns of geographical distribution of certain invertebrate biota.

Population regulation and demography in a harvested freshwater crayfish from Madagascar

Despite advances in statistical techniques for investigating population dynamics based on mark–recapture data, the majority of our understanding about demography and regulation comes from relatively few taxa. Most proposed generalisations about the association between demography and variation in population size are based on data from vertebrates, there are few sufficiently detailed invertebrate studies to examine whether these generalisations are widely supported. The population biology of freshwater invertebrates is especially poorly known. We present a large‐scale mark–recapture study of an endemic freshwater crayfish from Madagascar (Astacoides granulimanus). Variation in density, caused by difference in fishing pressure due to local taboos, allowed us to investigate density‐dependent regulation. We found evidence of density dependence in fecundity operating through the proportion of reproductive females by size but no significant evidence of density dependence in growth. Using a prospective analysis based on the elasticities from a size‐structured matrix model, we found that both recruitment rates and survival rates of large individuals were strongly associated with deterministic population growth – a result that differs from generalisations drawn from vertebrate studies. A central assumption in mark–recapture studies is that handling does not affect mortality. By treating the number of times an individual was captured as an individual covariate, easily done using the freeware program MARK, we were able to test for, and take account of, handling‐induced mortality. Our results show interesting similarities, and important differences, to generalisations based on vertebrate studies and emphasise the importance of population studies on poorly known taxa.

Simple traps for invertebrates

Four simple traps for dendrobiontic invertebrates and two light traps that attract nonflying (wingless and larval) forms of invertebrates are described. Along with data on phenology, population dynamics, and other aspects of invertebrate biology and ecology, the new traps provide the possibility of revealing migrations of entomophages and economically dangerous species in a timely manner, thereby improving the efficiency of pest population monitoring.

The Acquired Immune System: A Vantage from Beneath

The Acquired Immune System: A Vantage from Beneath

New environments, versatile genomes.

In this month's column we discuss three genome projects that reveal different aspects of microbial diversity and adaptability to different environmental niches; an impressively large community metagenomic sequencing project that has provided an enormous amount of data from a nutrient-poor aquatic environment; the sequence of an oral spirochete, Treponema denticola, which illustrates how readily related microorganisms adapt to different niches in the human body; and the first genome of a Wolbachia species, which sheds light on these fascinating bacterial manipulators of invertebrate biology.