Isopod Site

Description of a new species of the hyperparasitic barnacle <i>Duplorbis</i> Smith, 1906 and its cypris larva, with the molecular phylogenetic placement of the enigmatic family Duplorbidae Høeg & Rybakov, 1992 (Cirripedia: Rhizocephala)

Abstract Most species of Rhizocephala are obligate parasites of decapod crustaceans, but species in three families parasitize non-decapod hosts: Chthamalophilidae Bocquet-Védrine, 1961 (parasites of barnacles), Duplorbidae Høeg & Rybakov, 1992 (parasites of isopods and cumaceans), and Thompsoniidae Høeg & Rybakov, 1992 (mostly parasites of decapods but includes one species that is a parasite of stomatopods). Hyperparasitism (form of parasitism in which a secondary parasite lives on or in a primary parasite of a host) is extremely rare in Rhizocephala, but Duplorbis Smith, 1906, the type genus of the enigmatic family Duplorbidae, currently contains two named species hyperparasitic on bopyrid isopods (abdominal and branchial parasites of decapods) and one species on free-living isopods. A lectotype is selected for Duplorbis smithi Nierstrasz & Brender à Brandis, 1923. Recent work on the parasites of squat lobsters from New Zealand revealed a putative new species of this genus, described herein as Duplorbis korun. sp., hyperparasitic on branchial bopyrids of the genera Paragigantione Barnard, 1920 and Parapleurocryptella Bourdon, 1972. Each parasitized female bopyrid contained 3–8 externae of D. korun. sp. in the brood chamber. Externae of one host contained mature cypris larvae, a stage previously poorly known in this genus. These larvae are described herein using SEM and are shown to have a pair of long frontal filaments (retained from the nauplius stage), an exclusive feature shared among Duplorbidae. The first molecular (18S rRNA sequence) analysis of the family was also conducted. Duplorbids appear nested within a well-supported monophyletic lineage also comprising of Polyascidae Høeg & Glenner in Høeg, Noever, Rees, Crandall & Glenner, 2019, Polysaccidae Lützen & Takahashi, 1996, Clistosaccidae Boschma, 1928, Thompsoniidae Høeg & Rybakov, 1992, and Chthamalophilidae Bocquet-Védrine, 1961, most closely related to chthamalophilids. The discovery of this new species expands our knowledge of the species diversity, host use, and larval development of hyperparasitic rhizocephalans.

Termite

Termites are a group of eusocial insects which consume a variety of decaying plant material, generally in the form of wood, leaf litter, and soil humus. They are distinguished by their beaded (moniliform) antennae and the soft-bodied, unpigmented worker caste for which they have been commonly termed "white ants"; however, they are not ants but highly derived cockroaches; they are genetically closer to some cockroach groups than these are to other cockroaches. About 2,997 extant species are currently described, 2,125 of which are members of the family Termitidae.

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Spiracle (arthropods)

A spiracle or stigma is the opening in the exoskeletons of insects, myriapods, velvet worms and many arachnids that admits air into the respiratory system.

Termite Ecology in the First Two Decades of the 21st Century: A Review of Reviews

Termite ecology came of age in 1978 with the seminal review of Wood and Sands which by considering the quantitative contributions made by termites to the carbon cycle at the landscape level concluded that they were major players in tropical ecosystems. Subsequent field work in the succeeding two decades was summarised in 2000 by Bignell and Eggleton, the most recent review which attempted to cover the entire topic in detail, which included 188 listed references and has been extensively cited for almost 20 years. Subsequent summaries more narrowly defined or in some cases more superficial are listed in the bibliography. In this overview, the main and subsidiary headings in Bignell and Eggleton are revisited and reclassified in the light of 186 selected articles added to the relevant literature since 2000, and some earlier work. While the literature on termite ecology remains buoyant, it has declined relative to publications on other aspects of termite biology. Overall, the thesis that termites have a major impact on, and are major indicators of soil health and landscape integrity in the tropics and sub-tropics is maintained, but the drivers of local diversity, abundance and biomass remain complex, with many biographical, edaphic and optimum sampling issues not completely resolved. The large increase in diversity and abundance data from Neotropical biomes can also be noted.

Symbiotic organs in insects: diversity, functional implications, and terminology

Abstract With over a million described species, insects represent the most successful group of animals on Earth. One of the drivers of insect diversity is their ability to engage in multifold beneficial symbioses with microorganisms, often involving specialized host organs to accommodate intra- or extracellular symbionts. The existence of such organs and their importance for sustaining and transmitting beneficial symbionts has been known for over a century, and specific terms have been established for categorizing organs harbouring intracellular bacteria (bacteriomes) or fungi (mycetomes), or cuticular crypts containing extracellular fungi (mycetangia). For others, however, general terms are lacking, e.g. organs containing extracellular bacteria associated with the cuticle or with the digestive tract. Furthermore, previously established terms have been misused in other contexts. Notably, ‘bacteriome’ has been increasingly employed in the microbiome field to refer to bacterial communities, instead of the term’s original meaning of specialized organs housing intracellular bacterial symbionts. Here, we review and categorize the diversity of symbiotic organs in insects and propose a unified terminology. Our hope is that this common language will facilitate communication and thereby support the field of symbiosis research in unravelling commonalities and differences in the evolution, ecology, development, physiology and molecular basis across symbiotic interactions. This article is part of the theme issue ‘Life in natural microcosms’.

Mound-building termites

Mound-building termites are a group of termite species that live in mounds which are made of a combination of soil, termite saliva and dung. These termites live in Africa, Australia and South America. The mounds sometimes have a diameter of 30 metres (98 ft). Most of the mounds are in well-drained areas. Termite mounds usually outlive the colonies themselves. If the inner tunnels of the nest are exposed it is usually dead. Sometimes other colonies, of the same or different species, occupy a mound after the original builders' deaths.

Ecdysis

Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae.

Instar

An instar is a developmental stage of arthropods, such as insects, which occurs between each moult (ecdysis) until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width.

Mandible (insect mouthpart)

Insect mandibles are a pair of appendages near the insect's mouth, and the most anterior of the three pairs of oral appendages. Their function is typically to grasp, crush, or cut the insect's food, or to defend against predators or rivals. Insect mandibles, which appear to be evolutionarily derived from legs, move in the horizontal plane unlike those of vertebrates, which appear to be derived from gill arches and move vertically.

Bluesky Siphonophore Viewer

Posts now gather into a translucent siphonophore-like colony drifting through dark water. Oldest posts begin at one end of the spine and newer ones accumulate toward the other. Engagement thickens bells, membranes, and feeding clusters. Drag to orbit, mouse wheel to zoom, right-drag to pan, hover for a specimen overlay, click a segment to glide toward it, and double click the background to zoom to the whole organism.

Pluralistic: Technocarcinization (01 Jul 2026) – Pluralistic: Daily links from Cory Doctorow

"Carcinization" is a curious biological phenomenon: given enough time, across many environments, many species will evolve into crabs. The body-type of a crab, with its low center of gravity, sideways gait (useful for evading predators), ease of concealment and protected organs is suitable to many different environments:

Arthropod exoskeleton

Arthropods are covered with a tough, resilient integument, cuticle or exoskeleton of chitin. Generally the exoskeleton will have thickened areas in which the chitin is reinforced or stiffened by materials such as minerals or hardened proteins. This happens in parts of the body where there is a need for rigidity or elasticity. Typically the mineral crystals, mainly calcium carbonate, are deposited among the chitin and protein molecules in a process called biomineralization. The crystals and fibres interpenetrate and reinforce each other, the minerals supplying the hardness and resistance to compression, while the chitin supplies the tensile strength. Biomineralization occurs mainly in crustaceans. In insects and arachnids, the main reinforcing materials are various proteins hardened by linking the fibres in processes called sclerotisation and the hardened proteins are called sclerotin. The dorsal tergum, ventral sternum, and the lateral pleura form the hardened plates or sclerites of a typical body segment.