The cerebral ganglia of Milnesium tardigradum Doyère (Apochela, Tardigrada): Three dimensional reconstruction and notes on their ultrastructure

Differential interference contrast micrographs from stretched animals, serially sectioned semi-thin and ultrathin sections revealed that the cerebral ganglia (supraoesophageal mass) of the eulardigrade Milnesium tardigradum lie above the buccal tube and adjacent tissue like a saddle. It has an anterior indentation which is penetrated by two muscles that arise from the cuticle of the forehead. The cerebral ganglia consist of lateral outer lobes bearing an eye on each side, and two inner lobes which extend caudally. Between the inner lobes a cone-like projection tapers into a nerve bundle. Each outer lobe is joined with the first ventral ganglion. From the outer lobe near the eye the ganglion for a posterolateral sensory field extends to the epidermis. Anterior to the supraoesophageal mass are three dorsal ganglia for the upper three peribuccal papillae. Two additional ganglia attached to the cerebral mass supply the lateral cephalic papillae. The cerebral ganglia are covered by a thin neural lamella. The pericarya which surround the neuropil have large nuclei. Near the axons in the centre of the supraoesophageal mass the cytoplasm is crowded with vesicles of different size and appearance. Some of them resemble synaptic vesicles while others resemble dense core bodies. Structurally different types of synapses and axons can be distinguished within the neuropil.     

Revision of the Genera Apicalia A. Adams and Stilapex lredale and Description of Two New Genera (Mollusca, Prosobranchia, Eulimidae)

All species that have been described in Apicalia , except the type-species, are transferred to other eulimid genera. Three species earlier included in other genera and four new species are placed in Apicalia , viz. A. angulata sp.n. A, cicatricosa sp.n. A. echinasteri sp.n. (all three Queensland), and A. habei sp.n. (Japan). Those of which the hosts are known are all ectoparasites of asteroids. Two of the seven species previously included in Stilapex are excluded and four species earlier placed in other genera are transferred to Stilapex . The members of the latter genus are parasites of ophiuroids. Tropiometricola gen.n. is erected to include Stilifer sphaeroconcha Habe, a crinoid parasite. Parvioris gen.n. is described with Eulima fulvescens A. Adams as type species. A list of species described in eulimid genera and fitting Parvioris is given. P. australiensis sp.n. (W. Australia), P. blakeae sp.n. (Mauritius), P. mortoni sp.n. (Hong Kong), and P. noumeae sp.n. (New Caledonia) are described. Those species of which the host is known, are all ectoparasites of starfishes.     

Comparative morphology,functions, and homologies of the coxal glands in oribatid mites (Arachnida: Acari)

1. Forty-eight species of oribatids in 37 families representing most of the superfamilies were collected from various environments (littoral, salt marsh, litter, sod, and freshwater) and sectioned. 2. The coxal gland is composed of a sacculus and a labyrinth in all stages of all oribatid species. Muscles, originating on the body wall, insert at several points on the thin-walled sacculus which opens into the labyrinth. The labyrinth has an internal, chitinous supporting skeleton. The type A labyrinth has 3–180° bends, producing four parallel regions, and occurs in all inferior oribatids. The type B labyrinth has 1–180° bend, producing two parallel regions, and occurs in all superior oribatids. The coxal gland duct and the lateral gland duct join, penetrate the body wall, and empty into the posterior end of the podocephalic canal. All oribatids have lateral accessory glands, but only inferior oribatids have rostral and medial glands. Three ductless coxendral bodies are always present. 3. The labyrinth length in oribatids is correlated with body size and the environment of the species. Oribatids from sod, leaflitter, or moss show a simple correlation of labyrinth length (X) to total body length (Y) where Y = 4.64X. Freshwater species have a labyrinth length greater than that of comparably sized terrestrial species and salt water (littoral) species have a labyrinth length less than that of comparably sized terrestrial species. There is a greater reduction in labyrinth length in species restricted to salt marshes than in species not restricted to salt marshes. 4. The probable function of oribatid coxal glands is osmoregulation. Hemolymph filtration would occur across the sacculus by positive hemolymph pressure and contraction of the sacculus muscles. Resorption of ions would occur in the labyrinth, which is noncollapsible due to the internal skeleton. The hypothesis is that in freshwater species the rate of filtration is high and resorption of ions would have to be very efficient, therefore they have an elongated labyrinth; but in salt water species water loss must be minimized and preservation of ions would be a disadvantage, therefore they have a shortened labyrinth. Excre ion may also be a function of the coxal glands. The lateral gland may possibly function as an endocrine gland involved with production of a molting hormone. The rostral glands in inferior oribatids may have a salivary function. 5. The coxal glands of Peripatus, some millipedes, apterygote insects, decapod crustaceans, and all arachnid orders are homologous. The Tetrastigmata, Notostigmata, Cryptostigmata, and soft ticks have typical arachnid coxal glands. The coxal glands of higher Prostigmata may be modified into salivary, silk, or venom glands. The coxal glands in Mesostigmata, Astigmata, and hard ticks are lacking or highly modified.     

Histologic study of the lumbar glands of Pleurodema thaul (Amphibia, Anura, Leptodactylidae)

Frogs of the Pleurodema thaul species have a pair of prominent elevated cutaneous glands dorsolaterally, just posterior to the sacrum, which are named lumbar glands. We have studied histologically these glands and found that their chromatophores are disposed mainly immediately under the epidermis structuring a dermal chromatophore unit. Similar to the other anuran macroglands, the lumbar glands are constituted basically by granular alveoli filled with secretion. The presence of these granular alveoli and the typical distribution of the dermal chromatophores to suggest a defensive role for the lumbar glands. In most of the amphibians granular alveoli contain secretions with toxicity for several vertebrates. On the other hand, chromatophores in this frog species, probably play an aposematic function, since their disposition on the skin permits that the lumbar glands might be taken for eyes, probably giving to an eventual predator the impression that it may be an animal of higher dimensions.     

Proteinase, amylase, and proteinase-inhibitor activities in the gut of six cockroach species

Representative species, two from each of the cockroach families Blattidae, Blattellidae, and Blaberidae, have similar morphology of the digestive tract but differ in the physiology of digestion. The pH of crop and along the midgut varies in different species from 5.9 to 9.0 and the redox parameter from 10.1 to 12.9. Activities of proteinases and amylases in comparable gut regions differ among the species up to 100 times. Proteolytic activity is high in the midgut and moderate in the crop of Blattidae; in the other species, it is very low in the crop and increases to a moderate level in the posterior half of midgut (PM). The level of amylolytic activity is similar in the examined gut compartments of Blattidae and Blattellidae but low in the PM of Blaberidae. Blaberidae are also characterized by a high potential of the salivary glands, crop, and midgut to inhibit subtilisin, trypsin, and chymotrypsin. Inhibition of these proteinases by the extracts of salivary glands and gut is several orders of magnitude lower and often undetectable in the representatives of Blattidae and Blattellidae.     

The homology of cranial glands in turtles: with special reference to the nomenclature of salt glands

The cranial glands of ten species of turtles were studied by the use of histochemistry applied to serial sections of whole heads. The majority were stenohaline species, but one brackish water form, Malaclemys, was included. The results show that all species have two major orbital glands, an anterior Harderian gland, and a posterior lachrymal gland. The latter is seromucous in all species except Malaclemys terrapin in which the gland shows little evidence or organic secretion. External and medial nasal glands are found in all species studied, and also are seromucous glands. With these reslts, combined with a review of the literature the following conclusions are made. The Harderian gland is by definition the orbital gland opening through the medial surface of the nictitating membrane at or near the anterior canthus. It is of constant occurrence, and histological appearance, probably serving the same function. However, despite much recent study this function remains unknown. The lachrymal gland is defined as the orbital gland which opens through the lateral surface of the nictitating membrane, or medial surface of the lower eyelid, at or near the posterior canthus. It is of variable occurrence, absent in many reptiles, and has a histological structure which is also variable. In the stenohaline species it is apparently involved in organic secretion, while in the brackish water Malaclemys it may be involved in salt secretion, as it is in Cheloniidae. The nasal glands in turtles are probably homologous with the nasal salt glands of lizards and birds, but they do not appear to subserve the same function. In all species of turtles studied the nasal glands are seromucous. They are perhaps involved in the maintenance of the epithelium of the olfactory cavity.     

Morphology and chemistry of Dufour glands in four ectoparasitoids: Cephalonomia tarsalis,C. waterstoni (Hymenoptera: Bethylidae), Anisopteromalus calandrae,and Pteromalus cerealellae (Hymenoptera: Pteromalidae)

The venom apparatus of four hymenopterous parasitoids, including two bethylids, C. tarsalis (Ashmead) and C. waterstoni (Gahan), and two pteromalids, A. calandrae (Howard) and P. cerealellae (Ashmead), were removed and the associated Dufour glands characterized with respect to their external morphology and chemistry. Dufour glands in all four species have a characteristic translucent appearance that apparently results from their lipid content. The stalked Dufour glands of C. tarsalis and C. waterstoni are pear-shaped and have overall lengths of approximately 0.2 and 0.15 mm, respectively. The thin venom glands are bifurcate and insert through a fine duct into the transparent ovoid- to pear-shaped venom reservoir in these bethylids. In A. calandrae and P. cerealellae the Dufour glands are elongated, tubular structures of ca. 0.35 and 0.8 mm in length, respectively, that constrict to a short stalk that empties into the common oviduct. The venom glands in these pteromalids are simple elongated structures that insert into the sac-like venom reservoir through a fine duct. The chemistry of the volatile contents of the Dufour gland in these four species differs considerably. C. tarsalis Dufour glands contain the same hydrocarbon components as found on the cuticle of this species (Ann. Entomol. Soc. Am. 91:101-112 (1998)), and no other chemicals. The Dufour glands of C. waterstoni also contain only hydrocarbons, most of which are the same as the cuticular hydrocarbons (Ann. Entomol. Soc. Am. 85:317-325 (1992)), but in addition the Dufour gland contains ca. 3% of a mixture of 2,17- and 2,19-dimethyl C(23). A. calandrae Dufour gland chemistry is somewhat more complex than that of either of the two bethylids, but like the bethylids, only hydrocarbons are present. The carbon number range is from C(30) to C(39) and consists of a mixture of n-alkanes (C(30)-C(38)); 3-, 5-, 7-, 9-, 11-, 12-, 13-, 14-, 15- and 17-methyl alkanes; 3,7- and 3,11-dimethyl alkanes; 5,9- and 5,17-dimethyl alkanes; 7,11-, 9,13-, 13,17-, 14,18- and 15,19-dimethyl alkanes; 3,7,11- and 3, 9,15-trimethyl alkanes; and 3,7,11,15-tetramethyl alkanes. The cuticular hydrocarbons of this species have not been previously reported, but they are the same as the Dufour gland hydrocarbons. The Dufour glands of P. cerealellae contain both hydrocarbons and two long-chain aldehydes. Most of the hydrocarbons are identical to those found on the cuticle of this species (Ann. Entomol. Soc. Am. 94:152-158 (2001)), but in addition, 5,9-dimethyl C(27), 5,13-, 5,17- and 5,19-dimethyl C(35), 12- and 14-methyl C(36), 12,16- and 13,17-dimethyl C(36), 13-methyl C(37) and 13,17-dimethyl C(37) are present. The two aldehydes detected in glands from P. cerealellae are n-tetracosanal (C(23)CHO) and n-hexacosanal (C(25)CHO).     

Neotropical harvestmen (Arachnida,Opiliones) use sexually dimorphic glands to spread chemicals in the environment

Sexually dimorphic glands have convergently appeared in animals and are often responsible for the production of pheromones. In the suborder Laniatores of the order Opiliones (Arachnida), glands of such type are widespread, but there is not a single paper on how they are used. Using Scanning Electron Microscopy and a behavioral approach, we describe glandular openings and how these glands are used, in the harvestmen Gryne perlata and Gryne coccinelloides (Cosmetidae). Males of these two species have glandular openings on the metatarsi of legs I and on the metatarsi IV. Males were shown rubbing the glands of the metatarsi I against their other legs, whereas glands on the metatarsi IV are gently touched on the substrate or rubbed either against other legs, or against the substrate. Not all behaviors were seen in both species.     

The internal female genitalia of some Zygaenidae (Insecta,Lepidoptera): their morphology and remarks on their phylogenetie significance*

The internal female genitalia of fifteen species of Zygaenidae (representing seven genera of Zygaeninae), one species of Heterogynidae and one species of Limacodidae have been studied in order to delimit the distribution of Petersen's glands within the Zygaenidae. The study demonstrates a considerable amount of structural variation. Petersen's glands are found to represent an autapomorphic character of the Zygaeninae, while the pseudobursa is restricted to the Zygaenini. Most likely it is an autapomorphic character of this tribe. Some other characters that were studied are discussed with special reference to their usefulness for a reconstruction of the phylogeny of the Zygaenidae.     

Structure and development of bracteal nectary glands in Aphelandra (Acanthaceae)

A survey of bracteal (extrafloral) nectaries in species of Aphelandra (Acanthaceae) reveals substantial diversity. Each bracteal nectary is an aggregate of individual glands that vary in number, size, and structure among species. Glands contain three cell layers: a palisade-like secretory cell layer, a one-to-many-celled intermediate layer with thickened cell walls, and a foot layer. Members of the A. pulcherrima complex have one of two distinct gland types: relatively small glands with a single-celled intermediate layer or larger glands that have a multicellular intermediate layer. Nectaries composed of small glands are patches of many (>50) glands, whereas those composed of large glands are patches of < 10 glands. Four outgroup species have bracteal nectaries of numerous small glands with pluricellular intermediate layers. Glands of all three types are initiated as single enlarged protodermal cells, and all undergo similar early periclinal divisions; the large-gland type shows greater subsequent enlargement with many more anticlinal divisions. The bracteal nectar glands are interpreted to be homologous with simpler glandular trichomes, and mark a monophyletic lineage within Aphelandra. Comparisons with outgroup species show that both nectary types in the A. pulcherrima complex have diverged from an ancestral condition of numerous small glands with pluricellular intermediate layers. Use of the ontogenetic criterion to polarize gland type within the A. pulcherrima complex would yield erroneous results because evolution has apparently involved a developmental truncation with loss of cell divisions in the intermediate layer of small glands. Comparable nectar glands in more distant taxa are interpreted as remarkable cases of convergent evolution, perhaps from similar trichome precursors.     

青海高原二种双腔吸虫尾蚴腺体组织化学的比较观察

本文报道应用组织化学反应方法观察了青海高原中华双腔吸虫尾蚴及暂称为“B”型双腔尾蚴(可能是枝双腔尾蚴)二种单细胞腺体的组化成分及其生理功能。大单细胞腺体12—13对,内含丰富的碳水化合物——蛋白质复合物象粘蛋白之类物质,及酸性粘多糖。小单细胞腺3对,含结合氨基的蛋白质及甲性糖蛋白。二种双腔吸虫在贝类宿主体内子胞蚴及尾蚴组化威分很相似但从尾蚴粘液腺的结构可以区分二虫种。中华双腔吸虫粘球内包绕在尾蚴体外的粘液含丰富的粘蛋白。双腔吸虫幼虫期组化成分与阔盘吸虫相应的幼虫期进行了比较。     

Metapleural- and postpharyngeal-gland secretions from workers of the ants Solenopsis invicta and S. geminata

Chemical analyses by GC-MS of the metapleural glands (MG) from workers of Solenopsis invicta and S. geminata revealed for the first time the chemical composition of these glands and showed small differences between the two species. The MG of both species contain oleic, stearic, linoleic, and palmitic acid. Both ants, in addition, have small but significant amounts of hydrocarbons in their MG reservoir, which are the same as those found in their postpharyngeal glands (PPG). The PPG of both species contain alkanes, alkenes, and Me-branched alkanes. Each species is characterized by a specific composition of PPG chemicals with some overlap between species. These results suggest that the MG synthesizes mainly palmitic, linoleic, oleic, and stearic acids in these two ants, whereas PPG contains hydrocarbon mixes that widely vary between these two phylogenetically related species.     

Morphology of the fifth sternal glands of Neotropical social wasps (Hymenoptera,Vespidae, Polistinae)

Glands play a central role in the social behavior of insects, and comparative analysis of their structure may provide insights about their evolution and their role in insect social biology. Here, we describe the glands of the fifth metasomal sternite of ten polistine wasps with different social behaviors. The glands of foragers of these species were studied using semithin sections of Araldite‐embedded tissue, and scanning electron microscopy. The structure of the glands observed was mostly similar to what has previously been reported for independent‐founder and swarm‐founder species, respectively. Scale‐shaped modifications in the fifth sternite are reported for the first time for members of the genera Synoeca and Epipona. Two previously unreported glands in the fifth sternite are also described. A more restrictive definition of the name Richards' gland is proposed, applying to the class 3 cells associated with scale modifications of the fifth sternite, based on structural differences between the glands observed, homology requirements, and functional evidence. Previous phylogenetic reconstructions of this character suggest that it appeared early in the Vespidae and disappeared four times, with a single reappearance in the genus Vespula. The restricted definition of Richards' gland suggests that this structure is an exclusive trait of the Epiponini, with two reversals.     

Morphology and taxonomic distribution of a newly discovered feature,postero-lateral glands,in pelagic nemerteans

A variety of pelagic nemerteans from our collections off California and Hawaii between 1992 and 1997 have a pair of epidermal structures, usually visible on the intact specimens, located on the ventro-lateral margins near the caudal end of the body. The only previous reports of similar structures from pelagic or any other nemerteans are for two species of the genus Plotonemertes. Histological serial sections of at least one specimen from each of about 16 morpho-species demonstrate that these are specialized glandular regions of the epidermis, which we broadly term postero-lateral glands. The objects of this study are to describe these glands at the level of light microscopy and to consider their systematic implications and possible functions. Most of the glands consist of two more or less spatially segregated types of secretory cells. One type is usually at the anterior end of the gland and resembles typical mucous goblet cells. The other type usually is the more abundant, and resembles a nemertean serous cell, with secretion that probably is relatively proteinaceous. The glands of one of the Plotonemertes specimens have two additional types of secretory cells that are relatively abundant. This study reports on postero-lateral glands from 30 specimens: three specimens of Plotonemertes in the family Protopelagonemertidae, 18 in at least three genera of the family Pelagonemertidae, six in the monotypic family Balaenanemertidae, and three of Proarmaueria in the family Armaueriidae. The glands are relatively large, with large quantities of secretory vesicles, indicating that they must be of considerable importance to the animals. However, neither structure nor location offer self-evident clues to function of these glands. We also report on different forms of regional specialization in the epidermis of Crassonemertes and Nectonemertes, both of which lack postero-lateral glands.     

A new acanthocephalan family, the Isthmosacanthidae (Acanthocephala: Echinorhynchida), with the description of Isthmosacanthus fitzroyensis n. g., n. sp. from threadfin fishes (Polynemidae) of northern Australia

Isthmosacanthus fitzroyensis n. g., n. sp. is described from two species of protandrous fish, Eleutheronema tetradactylum (Shaw) and Polydactylus macrochir (Günther), from the waters around the coast of northern Australian. The new species can be distinguished from all others by the following combination of characters: proboscis shape and armature (22 rows of 13-14 hooks), short neck, trunk spined anteriorly and having two swellings (one bulbous) with a narrow isthmus in between, long tubular lemnisci and six tubular cement glands. Although I. fitzroyensis has been confused with a species of Pomphorhynchus Monticelli, 1905 in the literature, it can be distinguished from all pomphorhynchids, including species of Longicollum Yamaguti, 1935 and Pyriproboscis Amin, Abdullah & Mhaisen, 2003, by the suite of characters listed above. The placement of the species of Pyriproboscis in the Pomphorhynchidae Yamaguti, 1939 is problematical, because it has a short neck, two distinct hook types comprising the proboscis armature and only two rather than six cement glands. A new family, the Isthmosacanthidae n. fam., is erected to contain Isthmosacanthus together with Gorgorhynchoides Cable & Linderoth, 1963 and Golvanorhynchus Noronha, Fabio & Pinto, 1978, genera having an elongate to clavate proboscis, anterior trunk spines, elongate lemnisci, and six tubular cement glands. The validity of this determination, based on the importance of cement gland number and phylogenetic analysis, is argued.     

Ultrastructure of the submandibular gland of the rare white-winged vampire bat, Diaemus youngi

The submandibular gland of the white-winged vampire bat, Diaemus youngi, was examined by electron microscopy. Unlike typical submandibular glands, those in Diaemus have only one type of secretory cell in their endpieces, namely, serous cells. These serous cells are conventional in structure, with an extensive rough endoplasmic reticulum, scattered dictyosomes, and numerous secretory granules. The endpiece lumina, as well as intercellular canaliculi, are fitted with numerous microvilli, which also are present on the otherwise unremarkable intercalated duct cells. Striated ducts are of conventional morphology, but have a brush border-like array of microvilli on their luminal surface. These cells resemble those in the submandibular gland of the common vampire bat, Desmodus rotundus. The presence of an abundance of microvilli in the salivary glands in the two vampire bat species (and their absence from chiropteran species that consume other types of diets) is a strong indication that these structures play a significant role in dealing with the problems posed by a sanguivorous diet.     

Diversity and evolution of sexually dimorphic mental and lateral glands in Cophomantini treefrogs (Anura: Hylidae: Hylinae)

We describe the structure and histochemistry of mental and lateral glands in a representative array of 28 species of five genera of the Neotropical hylid frog tribe Cophomantini. Structural diversity was coded in 15 characters that were optimized on the most recent phylogenetic hypothesis. Mental and lateral glands occur in 17 species and 10 species, respectively, whereas nine species have both. Each glandular concentration may have two types of sexually dimorphic skin glands (SDSGs), specialized mucous and specialized serous glands, which occur independently or may co‐occur. Distinctive characteristics related to these glands are shape, aspect of the secretion, disposition, and distribution. The occurrences of mental and lateral glands, and the characters derived from macroscopic and microscopic examinations, have an intricate taxonomic distribution, with differing levels of homoplasy. The function of SDSGs in Cophomantini is currently unknown. However, based on structural and histochemical similarities to SDSGs from other species of amphibians where experimental evidence exists, we infer they might be involved in the secretion of chemical signals during courtship behaviour. The distribution pattern of these glands, along with the existence of different signals (i.e. acoustic, visual, tactile), suggests the presence of multimodal signalling for some species of the tribe. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114 , 12–34.     

Epidermal glands in cordylid lizards,with special reference to generation glands

We investigated inter‐ and intraspecific variation in epidermal gland characteristics in cordylid lizards. Our particular interest was whether a causal relationship exists between the presence of generation glands and lifestyle, i.e. in rock‐dwelling or ground‐dwelling lizards. We established that both femoral and generation glands are always present in adult males, but that species can be divided into three categories on the basis of the presence of these glands in adult females: both femoral and generation glands absent; femoral glands present, but generation glands absent; and both femoral and generation glands present. The absence of epidermal glands in females appears to be the basal condition in the Cordylidae. All cordylid species are sexually dimorphic as far as generation gland number is concerned, with females having consistently less glands than males. Gland number in females is strongly affected by climate, being lower in cooler compared with warmer environments. In males, there is no clear geographical pattern, although in some clades males of high‐altitude species have more generation glands than males of species occurring at lower altitudes. At least four of the five ground‐dwelling species in the family display unique generation gland characteristics, compared with rock‐dwelling species, reflecting the continued importance of generation glands in terrestrial environments. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 312–324.