Hepatic visceral larva migrans: A radiological case report.

Visceral larva migrans (VLM) occurs due to migration of the second stage of larvae of nematodes through human viscera. It is an underdiagnosed entity which commonly affects the liver as eosinophilic abscesses and appears as coalescing, conglomerated cavities on imaging. This case report details the sonographic and CT features of an 8 year old female patient with right upper quadrant pain and peripheral eosinophilia on laboratory reports, diagnosed as a case of VLM on biopsy. Imaging of VLM shows overlap with neoplastic lesions and other infective pathologies hence this case aims to highlight the clinical, laboratory, and radiological features to help narrow the differential diagnosis.

Comparative development of the serotonin- and FMRFamide-immunoreactive components of the nervous system in two distantly related ribbon worm species (Nemertea, Spiralia).

Introduction: Neurodevelopment in larval stages of non-model organisms, with a focus on the serotonin- and FMRFamide-immunoreactive components, has been in the focus of research in the recent past. However, some taxonomic groups remain understudied. Nemertea (ribbon worms) represent such an understudied clade with only few reports on nervous system development mostly from phylogenetically or developmentally derived species. It would be insightful to explore neurodevelopment in additional species to be able to document the diversity and deduce common patterns to trace the evolution of nervous system development. Methods: Fluorescent immunohistochemical labeling with polyclonal primary antibodies against serotonin and FMRF-amide and a monoclonal antibody against synapsin performed on series of fixed larval stages of two nemertean species Cephalothrix rufifrons (Archinemertea, Palaeonemertea) and Emplectonema gracile (Monostilifera, Hoplonemertea) were analyzed with confocal laser scanning microscopy. Results: This contribution gives detailed accounts on the development of the serotonin- and FMRFamide-immunoreactive subsets of the nervous system in two nemertean species from the first appearance of the respective signals. Additionally, data on synapsin-like immunoreactivity illustrates the general structure of neuropil components. Events common to both investigated species are the appearance of serotonin-like immunoreactive signals before the appearance of FMRF-like immunoreactive signals and the strict progression of the development of the lateral nerve cords from the anteriorly located, ring-shaped brain toward the posterior pole of the larva. Notable differences are (1) the proboscis nervous system that is developing much earlier in investigated larval stages of E. gracile and (2) distinct early, but apparently transient, serotonergic neurons on the frontal and caudal pole of the larva in E. gracile that seem to be absent in C. rufifrons. Discussion: According to the results from this investigation and in line with previously published accounts on nervous system development, the hypothetical last common ancestor of Nemertea had a ring-shaped brain arranged around the proboscis opening, from which a pair of ventro-lateral nerve cords develops in anterior to posterior progression. Early frontal and caudal serotonergic neurons that later degenerate or cease to express serotonin are an ancestral character of Nemertea that they share with several other spiralian clades.

Refinement of a technique for collecting and evaluating the osmolality of haemolymph from Drosophila larvae.

ex vivo physiological experiments using small insect models such as Drosophila larvae have become increasingly useful to address fundamental biological questions. To perform such experiments, various artificial saline solutions have been developed, but their osmolality varies significantly from one to the next. Such a variation of osmolality stems, in part, from the difficulty of determining the true value of haemolymph osmolality in Drosophila larvae. Thus, there is a pressing need to refine protocols for collecting and measuring the osmolality of the larval haemolymph. Two major obstacles are thought to impede the accurate analysis of haemolymph collected from small insects: melanin formation and gut-derived contamination. Here, we greatly refined existing haemolymph collecting methods, evaluated the purity of the collected haemolymph under melanin-free conditions, and concluded that the true value of haemolymph osmolality is close to 306.0 mOsm kg-1 in Drosophila larvae.

Structure and function of the larval teleost fish gill.

The fish gill is a multifunctional organ that is important in multiple physiological processes such as gas transfer, ionoregulation, and chemoreception. This characteristic organ of fishes has received much attention, yet an often-overlooked point is that larval fishes in most cases do not have a fully developed gill, and thus larval gills do not function identically as adult gills. In addition, large changes associated with gas exchange and ionoregulation happen in gills during the larval phase, leading to the oxygen and ionoregulatory hypotheses examining the environmental constraint that resulted in the evolution of gills. This review thus focuses exclusively on the larval fish gill of teleosts, summarizing the development of teleost larval fish gills and its function in gas transfer, ionoregulation, and chemoreception, and comparing and contrasting it to adult gills where applicable, while providing some insight into the oxygen vs ionoregulatory hypotheses debate.

Biology of Callistethus plagiicollis (Coleoptera: Scarabaeoidea: Rutelinae) and comparative morphology of its larvae.

Larvae of the beetle subfamily Rutelinae are poorly described in the literature. Notably, the morphology of the larvae of Callistethus plagiicollis Fairmaire has not previously been analyzed. Here, we report for the first time that these larvae feed on the tubers and roots of Gastrodia elata Blume, an important traditional Chinese herbal medicine, which causes a reduction in the yield and economic value of G. elata. We employed scanning electron microscopy and light microscopy to investigate the morphology and occurrence regularity of egg, larvae, pupae, and adult specimens of C. plagiicollis collected from the G. elata planting base in Guizhou Province, China, with a focus on the ultrastructure of mature larvae. The results revealed one generation of C. plagiicollis per year in the study area and three instar stages of larvae. Mature larvae were identified by the following characteristics: raster without palidia with a large number of hamate setae, antennal apex containing seven sensilla basiconica, larval haptomerum containing eight sensilla styloconica and four enlarged heli, and seven longitudinally arranged stridulatory teeth on the stipes of the maxilla. The combination of scanning electron and light microscopy effectively revealed the difference between membranous and sclerotized structures, ensuring accurate identification of C. plagiicollis larvae. By determining the feeding characteristics and occurrence regularity of C. plagiicollis, this study has implications for improved pest management in G. elata crops. RESEARCH HIGHLIGHTS: We identified C. plagiicollis as a new pest of G. elata, a traditional Chinese medicine Scanning electron and light microscopy were combined to analyze the morphology of the mature larvae of C. plagiicollis for the first time We determined the feeding characteristics and occurrence regularity of C. plagiicollis, which can be used to develop effective pest management strategies.

Graded FGF activity patterns distinct cell types within the apical sensory organ of the sea anemone Nematostella vectensis.

Bilaterian animals have evolved complex sensory organs comprised of distinct cell types that function coordinately to sense the environment. Each sensory unit has a defined architecture built from component cell types, including sensory cells, non-sensory support cells, and dedicated sensory neurons. Whether this characteristic cellular composition is present in the sensory organs of non-bilaterian animals is unknown. Here, we interrogate the cell type composition and gene regulatory networks controlling development of the larval apical sensory organ in the sea anemone Nematostella vectensis. Using single cell RNA sequencing and imaging approaches, we reveal two unique cell types in the Nematostella apical sensory organ, GABAergic sensory cells and a putative non-sensory support cell population. Further, we identify the paired-like (PRD) homeodomain gene prd146 as a specific sensory cell marker and show that Prd146+ sensory cells become post-mitotic after gastrulation. Genetic loss of function approaches show that Prd146 is essential for apical sensory organ development. Using a candidate gene knockdown approach, we place prd146 downstream of FGF signaling in the apical sensory organ gene regulatory network. Further, we demonstrate that an aboral FGF activity gradient coordinately regulates the specification of both sensory and support cells. Collectively, these experiments define the genetic basis for apical sensory organ development in a non-bilaterian animal and reveal an unanticipated degree of complexity in a prototypic sensory structure.

Hatching plasticity is associated with a more advanced stage at hatching in an Ambystoma with terrestrial eggs.

Hatching plasticity allows animals to initiate hatching in response to environmental cues including predation, flooding, and hypoxia. In species with terrestrial eggs but aquatic larvae, hatching plasticity often manifests as extended development of embryos when water is not available. Although these effects are taxonomically widespread, little attention has focused on differences in plasticity across closely related species with terrestrial and aquatic embryos. We propose that the terrestrial embryonic environment favors slower and prolonged development and, consequently, that we should see differences in development between closely related species that differ in where they lay their eggs. We test this hypothesis by comparing embryonic development between two mole salamanders, Ambystoma opacum and A. annulatum. Most Ambystoma lay eggs submerged in ponds but A. opacum lays its eggs on land, where hatching is triggered when eggs are submerged by rising pond levels. Embryos of both species were reared under common laboratory conditions simulating both aquatic and terrestrial nest sites. Consistent with our hypothesis, we found that A. opacum embryos exhibited slower development and took longer to hatch than A. annulatum embryos in both rearing environments. Furthermore, we observed in A. opacum a plasticity in hatching stage that was absent in A. annulatum. Our results indicate that the terrestrial-laying A. opacum has evolved slower and prolonged development relative to its aquatic-laying congener and suggest that embryonic survival in the unpredictable terrestrial environment may be facilitated by developmental plasticity.

Assessments of carbon nanotubes toxicities in zebrafish larvae using multiple physiological and molecular endpoints.

In recent years, carbon nanotubes (CNTs) have become one of the most promising materials for the technology industry. However, due to the extensive usage of these materials, they may be released into the environment, and cause toxicities to the organism. Here, their acute toxicities in zebrafish embryos and larvae were evaluated by using various assessments that may provide us with a novel perspective on their effects on aquatic animals. Before conducting the toxicity assessments, the CNTs were characterized as multiwall carbon nanotubes (MWCNTs) functionalized with hydroxyl and carboxyl groups, which improved their solubility and dispersibility. Based on the results, abnormalities in zebrafish behaviors were observed in the exposed groups, indicated by a reduction in tail coiling frequency and alterations in the locomotion as the response toward photo and vibration stimuli that might be due to the disruption in the neuromodulatory system and the formation of reactive oxygen species (ROS) by MWCNTs. Next, based on the respiratory rate assay, exposed larvae consumed more oxygen, which may be due to the injuries in the larval gill by the MWCNTs. Finally, even though no irregularity was observed in the exposed larval cardiac rhythm, abnormalities were shown in their cardiac physiology and blood flow with significant downregulation in several cardiac development-related gene expressions. To sum up, although the following studies are necessary to understand the exact mechanism of their toxicity, the current study demonstrated the environmental implications of MWCNTs in particularly low concentrations and short-term exposure, especially to aquatic organisms.

Follicular larva migrans.

Follicular larva migrans (FLM) is a rare and atypical clinical presentation of hookworm-related cutaneous larva migrans (HrCLM). FLM is characterized clinically by follicular, round, small, erythematous papules that are sometimes topped by vesicles or pustules. These lesions are usually located on the abdomen, back, buttocks and thighs and are accompanied by more or less severe pruritus. Some typical and/or short and fragmented tracks may also be visible. FLM is more resistant to anti-helminthic drugs than classical HrCLM: this is likely due to the deep location of larvae in hair follicles. We present two cases of FLM and a review of the literature.

Description of immature stages of Rhinusa species (Coleoptera, Curculionidae, Mecinini) with a focus on diagnostic morphological characters at the species and genus levels.

The mature larvae of the following fourteen Rhinusa species are described and illustrated: Rhinusaantirrhini (Paykull, 1800), R.asellus (Gravenhorst, 1807), R.collina (Gyllenhal, 1813), R.eversmanni (Rosenschoeld, 1838), R.florum (Rubsaamen, 1895), R.herbarum (H. Brisout de Barneville, 1862), R.incana (Kirsch, 1881), R.linariae (Panzer, 1796), R.melas (Boheman, 1838), R.neta (Germar, 1821), R.pilosa (Gyllenhal, 1838), R.rara Tosevski & Caldara, 2015, R.tetra (Fabricius, 1792), and R.vestita (Germar, 1821). The pupae of thirteen of them (except R.incana) were also described. The comparison of larval morphological characters and plant preferences provides evidence supporting the existence of different species groups previously established according to a phylogenetic analysis based on adult morphological characters. The following diagnostic attributes distinguishing the genus Rhinusa are highlighted. For the larvae: (1) pronotal shield indistinct; (2) thoracic prodorsal fold small or even vestigial; (3) abdominal postdorsal folds (especially of segments III-VII) high or even in the form of conical protuberances; (4) cuticle of abdominal segments densely covered with asperities; (5) cuticle without dark spots or dark pigmentation; (6) head suboval, rarely round; (7) labrum usually with 2 als; (8) des1 short or absent, rarely elongated; and (9) fs1-3 usually absent or minute. For the pupae: (1) body stout; (2) head protuberances always present; (3) pronotal protuberances (if present), separated at bases of the pronotum, always wider than higher; (4) abdominal protuberance usually present, wide or round; (5) femora usually with a single fes; and (6) urogomphi short or vestigial. Keys to the larvae and pupae described here are provided. All the characters used for identification are illustrated by photographs or drawings. Biological and distribution data, including new information, are provided for all the species studied.

First Morpho-Functional Assessment of Immature Stages of Pelecocera Species (Diptera: Syrphidae) Feeding on False Truffles.

With 14 species, Pelecocera Meigen, 1822 is a scarce and small genus of hoverflies (Diptera: Syrphidae: Rhingiini) from the Holarctic Region. Apart from the finding of larvae of Pelecocera (Chamaesyrphus) japonica (Shiraki, 1956) in fungi in Japan, the larval biology of these hoverflies is virtually unknown. The early stages of all Pelecocera species are undescribed. The adults of Pelecocera (Pelecocera) tricincta Meigen, 1822 and Pelecocera (Chamaesyrphus) lugubris Perris, 1839 are found in Palearctic conifer forests with sand dunes. We here report the first morphological evidence of the immature stages of Pelecocera (P. lugubris and P. tricincta), as well as specific data on their breeding sites. Larvae of both species were collected feeding on the hypogean basidiomycete Rhizopogon luteolus Fr. & Nordholm, 1817 in Denmark in 2021. The first larval stage and second larval stage of P. tricincta, the third larval stage of P. lugubris, the anterior respiratory process, and the posterior respiratory process of the puparia of these two species were analyzed and studied using stereomicroscope and scanning electron microscope techniques. The chaetotaxy of the puparium of each species is also described and illustrated. A taxonomic diagnosis of the larvae of the genus Pelecocera is proposed to separate them from the larvae of other genera of the tribe.

Cerebral baylisascariosis in a rainbow lorikeet (Trichoglossus moluccanus) in a German Zoo.

BACKGROUND: The raccoon roundworm, Baylisascaris procyonis, can cause a meningoencephalitis as neural larva migrans which is known in avian species, including rainbow lorikeets in North America, but has not been described in Old World parrots in Germany yet. CASE PRESENTATION: A 2-month-old, male rainbow lorikeet from a zoo in Germany was submitted for necropsy. Prior to death the animal had progressive neurological signs like apathy and torticollis. In the cerebrum a focally extensive severe granulomatous to necrotizing encephalitis with an intralesional larval nematode was diagnosed. Based on the clinical and pathological findings, the larval morphology and the epidemiological background, the larva was identified as Baylisascaris procyonis. CONCLUSIONS: Cerebral baylisascariosis should be considered as a differential diagnosis in zoo and pet birds with neurological signs having contact to racoons or rather racoon faeces in Germany due to the high prevalence of Baylisascaris procyonis in the German raccoon population.

The ultrastructure of the apical organ of Curini-Galletti's larva, a new polyclad larval type.

Polycladida are the only free-living flatworms with a planktonic larval stage in some species. Currently, it is not clear if a larval stage is ancestral in polyclads, and which type of larva that would be. Known polyclad larvae are Müller's larva, Kato's larva and Goette's larva, differing by body shape and the number of lobes and eyes. A valuable character for the comparison and characterisation of polyclad larval types is the ultrastructural composition of the apical organ. This organ is situated at the anterior pole of the larva and is associated with at least one ciliary tuft. The larval apical organ of Theama mediterranea features two multiciliated apical tuft sensory cells. Six unfurcated apical tuft gland cell necks are sandwiched between the apical tuft sensory cells and two anchor cells and have their cell bodies located lateral to the brain. Another type of apical gland cell necks is embedded in the anchor cells. Ventral to the apical tuft, ciliated sensory neurons are present, which are neighbouring the cell necks of two furcated apical tuft gland cells. Based on the ultrastructural organisation of the apical organ and other morphological features, like a laterally flattened wedge-shaped body and three very small lobes, we recognise the larva of T. mediterranea as a new larval type, which we name Curini-Galletti's larva after its first discoverer. The ultrastructural similarities of the apical organ in different polyclad larvae support their possible homology, that is, all polyclad larvae have likely evolved from a common larva.

Sea cucumbers: an emerging system in evo-devo.

A challenge for evolutionary developmental (evo-devo) biology is to expand the breadth of research organisms used to investigate how animal diversity has evolved through changes in embryonic development. New experimental systems should couple a relevant phylogenetic position with available molecular tools and genomic resources. As a phylum of the sister group to chordates, echinoderms extensively contributed to our knowledge of embryonic patterning, organ development and cell-type evolution. Echinoderms display a variety of larval forms with diverse shapes, making them a suitable group to compare the evolution of embryonic developmental strategies. However, because of the laboratory accessibility and the already available techniques, most studies focus on sea urchins and sea stars mainly. As a comparative approach, the field would benefit from including information on other members of this group, like the sea cucumbers (holothuroids), for which little is known on the molecular basis of their development. Here, we review the spawning and culture methods, the available morphological and molecular information, and the current state of genomic and transcriptomic resources on sea cucumbers. With the goal of making this system accessible to the broader community, we discuss how sea cucumber embryos and larvae can be a powerful system to address the open questions in evo-devo, including understanding the origins of bilaterian structures.

Oscillators and servomechanisms in navigation and orientation.

I summarize my recent theorizing on orientation and navigation across life. Organisms use navigational servomechanisms working with oscillators to get to goals. Navigational servomechanisms track errors from the best direction of travel and initiate action to correct the error. They work with endogenously generated action patterns, oscillations produced by oscillators, to adjust the course of travel. The theme applies to all scales of life from micrometers to thousands of kilometers. Servomechanisms and oscillators also characterize some other domains of cognition.

Cutaneous larva migrans in a child: a case report and review of literature.

Introduction: Cutaneous larva migrans (CLM) is a dermatitis caused by the invasion and migration of parasitic larvae of hookworms, primarily affecting tropical and subtropical regions. This report presents a case of CLM in a Nepali child and provides an overview of the literature on this condition. Case report: A 4-year-old boy from a rural area in Nepal presented with a pruritic skin lesion on his left foot, initially misdiagnosed as fungal infection. The lesion gradually expanded, forming a serpiginous erythema, and became intensely pruritic. The patient's family had poor socioeconomic conditions, and the child frequently walked barefoot in an area with many domestic and stray dogs. Diagnosis was confirmed clinically, and treatment with oral albendazole and antihistamines resulted in complete resolution of symptoms. Discussion: CLM is a neglected zoonotic disease, with an underestimated burden in developing countries due to underreporting and misdiagnosis. The larvae of Ancylostoma spp. are common culprits, causing a localized inflammatory reaction as they migrate through the skin. Diagnosis is mainly clinical and routine investigations usually reveal no abnormality. Complications may include secondary bacterial infections, allergies, and rare migration to internal organs. Treatment options include albendazole or ivermectin, with preventive measures emphasizing hygiene, footwear use, and pet deworming. Conclusion: CLM is a neglected disease that primarily affects marginalized communities in tropical regions. Raising awareness among healthcare providers, conducting observational studies, and developing treatment guidelines, especially for children, are essential steps to address this public health concern. Preventive efforts, such as promoting hygiene and footwear use, should be encouraged to reduce CLM incidence.

Epimorphic development in tropical shallow-water Nymphonidae (Arthropoda: Pycnogonida) revealed by fluorescence imaging.

BACKGROUND: Extant lineages of sea spiders (Pycnogonida) exhibit different types of development. Most commonly, pycnogonids hatch as a minute, feeding protonymphon larva with subsequent anamorphic development. However, especially in cold water habitats at higher latitudes and in the deep sea, some taxa have large, lecithotrophic larvae, or even undergo extended embryonic development with significantly advanced postlarval hatching stages. Similar biogeographic trends are observed in other marine invertebrates, often referred to as "Thorson's rule". RESULTS: To expand our knowledge on the developmental diversity in the most speciose pycnogonid genus Nymphon, we studied the developmental stages of the two tropical representatives N. floridanum and N. micronesicum., We compared classical scanning electron microscopy with fluorescence-based approaches to determine which imaging strategy is better suited for the ethanol-fixed material available. Both species show epimorphic development and hatch as an advanced, lecithotrophic postlarval instar possessing the anlagen of all body segments. Leg pairs 1-3 show a considerable degree of differentiation at hatching, but their proximal regions remain coiled and hidden under the cuticle of the hatching instar. The adult palp and oviger are not anteceded by three-articled larval limbs, but differentiate directly from non-articulated limb buds during postembryonic development. CONCLUSIONS: Fluorescence imaging yielded more reliable morphological data than classical scanning electron microscopy, being the method of choice for maximal information gain from rare and fragile sea spider samples fixed in high-percentage ethanol. The discovery of epimorphic development with lecithotrophic postlarval instars in two small Nymphon species from tropical shallow-water habitats challenges the notion that this developmental pathway represents an exclusive cold-water adaptation in Nymphonidae. Instead, close phylogenetic affinities to the likewise more direct-developing Callipallenidae hint at a common evolutionary origin of this trait in the clade Nymphonoidea (Callipallenidae + Nymphonidae). The lack of functional palpal and ovigeral larval limbs in callipallenids and postlarval hatchers among nymphonids may be a derived character of Nymphonoidea. To further test this hypothesis, a stable and well-resolved phylogenetic backbone for Nymphonoidea is key.

Key for the identification of third instar larvae of African blowflies (Diptera: Calliphoridae) of forensic importance in death investigations.

Blowfly larvae are the insects primarily responsible for the active stage of decomposition of exposed vertebrate remains and are the most frequently collected entomological evidence during forensic investigations of death. The necrophagous calliphorids in continental Africa that consistently develop on large vertebrate carrion include 11 species belonging to four genera: Calliphora, Chrysomya, Hemipyrellia and Lucilia. Most of these species are widespread in Africa and frequently reported on large animal carcasses and carrion and human corpses. A few keys have been compiled for identification of their third instar larvae, but none of them covers the complete set of taxa. Therefore, we provide a new comprehensive key with original illustrations of all taxonomically significant characters. The key is based on characters that should be easily observable even in poorly equipped local laboratories and is a reliable taxonomic tool for material collected in either urban or rural areas where synanthropic species predominate. However, it should be used with some caution in areas with relatively pristine natural habitats, where additional carrion-breeding species may occur. The publication of the key will significantly facilitate both medical and forensic entomological research and practice in Africa.