Rosette Glands Research Articles

Description of the larval and adult hindgut tract of the common spider crab Maja brachydactyla Balss, 1922 (Brachyura, Decapoda, Malacostraca).

Arthropods are the most diversified animals on Earth. The morphology of the digestive system has been widely studied in insects; however, crustaceans have received comparatively little attention. This study describes the hindgut tract of the common spider crab Maja brachydactyla Balss, 1922, in larvae and adults using dissection, light and electron microscopical analyses. The hindgut tract maintains a similar general shape in larvae and adults. Major differences among stages are found in the morphology of epithelial cells and microspines, the thickness of the cuticle and connective-like tissue, and the presence of rosette glands (only in adults). Here, we provide the description of the sub-cellular structure of the folds, epithelium (conformed by tendon cells), musculature, and microspines of the hindgut of larvae and adults of M. brachydactyla. The morphological features of the hindgut of M. brachydactyla are compared with those of other arthropods (Insecta, Myriapoda and Arachnida). Our results suggest that the morphology of the hindgut is associated mainly with transport of faeces. In adults, the hindgut may also exert an osmoregulatory function, as described in other arthropods. At difference from holometabolous insets, the hindgut of M. brachydactyla (Decapoda) does not undergo a true metamorphic change during development, but major changes observed between larval and adult stages might respond to the different body size between life stages.

Morphology and ultrastructure of the esophagus during the ontogeny of the spider crab Maja brachydactyla (Decapoda, Brachyura, Majidae).

The esophagus of the eucrustaceans is known as a short tube that connects the mouth with the stomach but has generally received little attention by the carcinologists, especially during the larval stages. By this reason, the present study is focused on the morphology and ultrastructure of the esophagus in the brachyuran Maja brachydactyla during the larval development and adult stage. The esophagus shows internally four longitudinal folds. The simple columnar epithelium is covered by a thick cuticle. The epithelial cells of the adults are intensively interdigitated and show abundant apical mitochondria and bundles of filamentous structures. The cuticle surface has microspines and mutually exclusive pores. Three muscle layers surrounded by the connective tissue are reported: circular muscles forming a broad continuous band, longitudinal muscle bundles adjacent to the circular muscles, and dilator muscles crossing the connective tissue vertically toward the epithelium. The connective tissue has rosette glands. The esophagus of the larvae have epithelial cells with big vesicles but poorly developed interdigitations and filamentous structures, the cuticle is formed by a procuticle without differentiated exocuticle and endocuticle, the connective layer is thin and the rosette glands are absent. The observed features can be explained by his role in the swallowing of the food.

Aspects of mast building and the fine structure of “amphipod silk” glands in Dyopedos bispinis (Amphipoda, Dulichiidae)

In the present study, we investigated the biology of Dyopedos bispinis, a mast-building amphipod that is abundant near the N. Pertsov White Sea Biological Station. To examine the peculiarities of mast building in Dyopedos bispinis, we studied the social structure of individuals inhabiting the masts and identified the preferred substrata through underwater photography and direct observations, characterized the internal and external structures of the masts, and studied the ultrastructure of pereopodal silk glands using scanning and transmission electron microscopy (SEM and TEM, respectively). The most frequent substrata for mast building are other fouling organisms, including hydroids, bryozoans, ascidians and sponges. As in other corophiids, each Dyopedos bispinis mast represents the territory of one female and, occasionally, one male, but unique collective masts occupied by three or more (up to 23) adults were also observed. Masts comprise one or 2-4 central cylinders and a laminated cortex that contains detritus and amphipod silk layers. The pereopodal glandular complex of Dyopedos bispinis is composed of two distinct gland groups, proximal and distal, in each pereopod 3-4, and ducts in the glandular complex lead into a common chamber in the dactylus. The proximal glands are multicellular; their secretory cells are uninuclear, unlike in certain other amphipods; and the cell membrane is deeply invaginated. The invaginations are filled with extensions of the cytoplasm of lining cells, but the origin of the lining is unclear. Axon terminals were observed adjacent to the secretory cells, and it is assumed that these axons regulate amphipod silk glands. The proximal silk glands of Dyopedos bispinis have similarities with the lobed and rosette glands of isopods, but they have strongly elongated forms. We refer to these glands as pseudotubular glands. Such glands are rarely observed in Crustacea and have only been described in silk-producing pereopodal systems of marine Peracarida and in the antenna of terrestrial Malacostraca.

Morphology and fluorescence of the parapodial light glands in Tomopteris helgolandica and allies (Phyllodocida: Tomopteridae)

The histology of putative light organs in the parapodia of five species of Tomopteris (pelagic annelids) is examined and compared using light, epifluorescence and scanning electron microscopy. The structural homology of rosette glands in the parapodial pinnae of the tail-bearing species T. helgolandica and T. pacifica, and hyaline glands of the tail-less species T. carpenteri, T. planktonis and T. septentrionalis is highlighted. However, the rosette glands point towards the ramus of the coelomic cavity inside the parapodia, whereas the hyaline glands point towards the surrounding water and penetrate the pinnal surface on the posterior side of the parapodia. Further, in order to assess the photogenic properties of rosette glands from T. helgolandica, we analysed the distribution and the temporal dynamics of their endogenous fluorescence in isolated parapodia in response to light emission induced by KCl and carbachol. The gradual extinction of bioluminescence was combined to the centrifugal spread of fluorescence from the core of the gland. We suggest this fluorescence to be produced by a “breakdown” product of the chemiluminescent reaction. Finally, both gland types probably evolved from a common light-emitting structure and differentiated along a functional and migrational axis extending from endocrine secretion close to the coelomic ramus to exocrine secretion close to the lateral margin of the pinna.

Plasticity of morphological traits in response to social conditions in a simultaneous hermaphrodite

According to sex allocation theory, hermaphrodites allocate a fixed amount of resources to their male and female functions, and the proportion of resources invested in each sex depends on the mating group size. Measures of trade-offs between male and female functions are usually made directly by estimating the number of gametes or the size of the gonads. In this study, we focused on the effect of social conditions (i.e. mating opportunities) on the expression of some morphological traits and on their plasticity in the protandrous simultaneously hermaphrodite Ophryotrocha diadema. We investigated whether in O. diadema the morphological traits, which are dimorphic in Ophryotrocha dioecious species – upper-jaw size, prostomium size, body size and number of rosette glands − are plastic when they respond to variations in social conditions and whether variations in these traits are associated with variations in male and/or female reproductive success. Plasticity of the traits was analysed during both the juvenile and the adult phases in order to check whether phenotypic plasticity is limited to the developmental phase or can be manifested throughout the whole lifespan of the animals. Our results showed that the number of rosette glands, the upper-jaw size and the prostomium size are traits that are plastic in O. diadema. Indeed, the number and size of these traits changed according to the variation of social conditions. However, we found no association between the plastic morphological traits and male or female reproductive success.

Diverse pereopodal secretory systems implicated in thread production in an apseudomorph tanaidacean crustacean.

Among arthropods, various insects, spiders, and crustaceans produce thread. The crustacean Tanaidacea include species that use thread mainly to construct dwelling tubes. While thread production was previously known only in Tanaoidea and Paratanaoidea, it was recently discovered in two species in Kalliapseudidae (Apseudoidea), although information on the morphology of the thread-producing system was lacking. Using histology, light and scanning electron microscopy, we found that the kalliapseudid Phoxokalliapseudes tomiokaensis comb. nov. lacks the sort of glandular structures associated with thread production in the pereonites, but has these structures in pereopods 1-6. We observed four types of glandular systems defined by the types and distribution of glands they contain: Type A (pereopod 1), Type B (pereopods 2 and 3), Type C (pereopods 4 and 5), and Type D (pereopod 6). All types have small rosette glands and lobed glands; Type A additionally has large rosette glands. The inferred thread-producing apparatus in P. tomiokaensis is very different from that in Tanaoidea and Paratanaoidea, suggesting that kalliapseudids evolved thread production independently from the latter two groups.

Microscopic anatomy of male tegumental glands and associated cuticular structures in Titanethes albus (Crustacea: Isopoda)

Male glandular organs characterized by porous surfaces with hair-like cuticular elaborations are known from several trichoniscid isopods. In the subterranean species Titanethes albus, males possess paired tubercles with numerous hairs and pores dorsally on the pleon. We analyzed the microscopic anatomy of these structures with scanning and transmission electron microscopy. Diverse epicuticular formations and numerous sensilla, which are probably chemoreceptive, are present on the tubercles. We found several secretory surfaces on the pleon in addition to the dorsal tubercles. We also examined the distribution, architecture and ultrastructure of male-specific glands in T. albus with light and transmission electron microscopy. Three distinct types of male-specific rosette glands are present in different parts of the pleon and in the uropods. Glands secreting on the dorsal tubercles contain stellar central cells. The ultrastructure and histochemical staining properties of male-specific glands in T. albus suggest that they produce peptides which might function as contact pheromones.

The Ophryotrocha diadema group (Annelida: Dorvilleidae), with the description of two new species

This paper reviews a group of hermaphroditic Ophryotrocha species, here designated as the O. diadema group. This informal group is characterised by its unique P-maxillae and paired mammillate rosette glands. The three members of the group are simultaneous hermaphrodites and have the chromosome complement of 2n = 8. As herein defined, the group includes O. diadema, O. alborana sp. nov., and O. birgittae sp. nov.. The three species can be distinguished by the appearance of their eyes and other morphological and reproductive differences. The species are described, and their life table data is presented.

Copulatory system of the spider crab Libinia spinosa (Crustacea: Brachyura: Majoidea)

Functional morphology of the male gonopods, female holding systems and vulvae of Libinia spinosa are described using scanning electron microscopy and histological sections, establishing differences between immature and mature individuals. The first gonopod of mature males, larger than 35.1 mm of carapace width (CW), is long, slender, and ending in two wing-like processes; abdominal, characterized by the presence of a sub-terminal seminal canal, and sternal, closed and where the cuticle holds setae. In immature males, smaller than 29.9 mm CW, both processes are shorter, and the tip of the abdominal process closed. Six different types of setae are described for both gonopods. Internally, the gonopods have rosette glands in immature and mature individuals. The presence of secretions, which may be involved in the moulting process, was observed in immature males towards the external cuticle corresponding to the rosette glands. The rosette glands may be related to reproduction in mature males. Females presented a press-button holding system and a biconcave vulva. In immature females, smaller than 36.1 mm CW, the vulva aperture was closed by integument bulging to the outside. In mature females, larger than 42.6 mm CW, the locking system was almost fused to the cuticle, and the vulvae showed an open biconcave form with a more inner flexible membrane. Morphological characteristics shown by the gonopods of mature males develop synchronously with the acquisition of physiological maturity, not with morphometrical maturity. The mature holding systems and vulvae of females are developed synchronously with physiological and morphometrical maturity.

The Ophryotrocha labronica group (Annelida: Dorvilleidae)— with the description of seven new species

This paper reviews the group of gonochoristic Ophryotrocha species, known as the “O. labronica group”. This informal group is chararacterised by its unique maxillary P- and K-forceps and dorsomedian rosette glands. All members of the group are primarily gonochoristic and almost all have the diploid complement of chromosomes of 2n = 6. External morphological differences within the group are very slight. In males and females of all species the P-type maxillae change at maturity to the K-type with the right forceps being bifid. A jaw fossil from the Upper Cretaceous, attributable to the O. labronica group, attests to the long history of the group. As herein defined, the group includes: O. labronica labronica, O. labronica pacifica, O. costlowi sp. nov., O. dimorphica, O. japonica sp. nov., O. macrovifera sp. nov., O. notoglandulata, O. permanae sp. nov., O. robusta sp. nov., O. rubra sp. nov., O. schubravyi, O. vellae sp. nov., O. olympica, nom. nud., O. prolifica, nom. nud., and O. sativa, nom. nud.. Seven species are formally described and diagnoses are provided for all remaining taxa in the taxonomic section. This is followed by an illustrated discussion of the morphology, reproductive traits, and relationships of the members of the informal group.

Redescription of Ophryotrocha puerilis and O. labronica (Annelida, Dorvilleidae)

For more than a century, it has been pointed out that most features of the original description of Ophryotrocha puerilis Claparède & Mecznikow, 1869, probably based on a mixed population of two sympatric species, agree better with the subsequently described O. labronica La Greca & Bacci, 1962. Although O. labronica was described as a protandrous hermaphrodite that could self-fertilize, the widely distributed species is mainly gonochoristic. We will designate neotypes, redescribe these two polychaetes and review their reproduction and development to remove any confusion and uncertainty surrounding the identity of these two well-known polychaetes. We will also discuss the growth and replacement of the maxillary apparatus and the morphology and distribution of the rosette glands, providing support for the molecular phylogeny of selected Ophryotrocha species.

Rosette-type tegumental glands associated with aesthetasc sensilla in the olfactory organ of the Caribbean spiny lobster, Panulirus argus

The lateral antennular flagellum of decapod crustaceans bears unique olfactory sensilla, namely the aesthetascs, and other sensilla types. In this study, we identify a new major tissue in the lateral flagellum of the Caribbean spiny lobster, Panulirus argus, namely "aesthetasc tegumental glands" (ATGs), based on immunostaining with antibodies against CUB serine protease (Csp), in situ hybridization with csp-specific probes, labeling with the F-actin marker phalloidin, labeling with the nuclear marker Hoechst 33258, and staining with methylene blue. Each ATG has 12-20 secretory cells arranged in a rosette. Each secretory cell has a Csp-immunoreactive basal portion and an apical portion containing granular material (metachromatic staining indicative of acid mucopolysaccharides). At the center of each secretory rosette is a phalloidin-positive common locus that gives rise to a main drainage duct projecting toward the cuticle. Scanning electron and light microscopy show that thin ducts traverse the cuticle and connect to "peg pores" proximal to the bases of the aesthetascs, with 3.4 peg pores per aesthetasc. Since the number of common loci is correlated with the number of peg pores, we conclude that each pore represents the outlet of one ATG, and that the secretions are released from them. We conclude further that ATGs and aesthetascs are functionally linked. We hypothesize that ATG secretions have antifouling and/or friction-reducing properties, and that they are spread over the surface of the aesthetascs by antennular grooming. A review of the literature suggests that ATGs are common in decapod crustacean antennules, and that rosette glands and grooming might be functionally coupled in other body areas.

Morphology and function of the copulatory system in freshwater crabs of the genus Potamon.

To understand the reproductive processes of freshwater crabs of the genus Potamon, we examined the first and second gonopod and the gonoducts of the female by histological methods. The gonopods are highly modified compared to those of other brachyuran crabs. In particular, the second gonopod is unusually long and has a special morphology, ending in a long sclerotized tube. Suggestions for the function of both gonopods and their different parts are presented. Tubulation of the first and second gonopod is observed. Rosette glands, which are abundant in the subterminal joint of the first gonopod, are connected to the sperm channel by cuticular pores. In females, the chitinous parts of the inner vulva may prove to have a more constant morphology than the external flexible structures. J. Morphol. 239:157-166, 1999. © 1999 Wiley-Liss, Inc.

The role of tegumental glands in burrow construction by two Mediterranean callianassid shrimp

Two species of Mediterranean callianassid shrimp (Callianassa candida andCallianassa tyrrhena) have been observed in aquaria to work sediment into the burrow wall while manipulating it with the mxp3, P2, and P3. Histological sections of the appendages involved in manipulating the burrow wall show numerous multicellular glands (“rosette glands”). SEM investigations of the appendages reveal surface pores with emanating mucus threads. These observations suggest that mucus excreted from tegumental glands in mxp3, P2, and P3 is used to stabilise the burrow wall.

NEPHROPORE ROSETTE GLANDS OF THE LOBSTER HOMARUS AMERICANUS: POSSIBLE SOURCES OF URINE PHEROMONES

ABSTRACT This study examined the nephropore area of sexually mature lobsters for the presence of structures capable of producing chemical signals in conjunction with urine release. Urine signals are used for chemical communication in the lobster Homarus americanus. Male urine plays a role in the determination of dominance and female choice of dominant males, while female urine reduces the incidence of male aggressive behavior and induces male mating behavior. Masses of rosette glands were found, lateral and medial to the ureter of all animals examined. Staining properties and gland morphology suggest that nephropore rosettes are active in males and females, in all molt stages and at all times of the year. Rosette glands stained positively for protein and mucopolysaccharides. Gland complexes did not show histochemical evidence of phenoloxidase, a product of some crustacean rosette glands. Nephropore rosette glands were packaged into clusters, which in turn were organized into lateral and medial gland complexes lying alongside each ureter. Complexes were joined by a common duct terminating at the bladder, while rosettes in some anterior clusters were served by individual ducts passing through the nephropore sphincter and terminating outside the animal adjacent to the site of urine release. These two duct systems could allow gland complexes to release their products into the environment with or without concomitant urine release, and as such these glands are good candidates for sources of chemical signals.

Feeding by penaeid prawns: the role of the anterior mouthparts

Penaeid prawns can feed micro- and macrophagously. During ingestion food secured by the pereiopods and maxillipeds III and II is manoeuvered into the oesophagus by the co-ordinated action of maxillipeds I, maxillae II and I, the paragnaths, mandibles and labrum. Prey items >5.00 mm 2 are pushed directly between the mandibles by the strongly hooked setae on the basipodites of maxillae I, while particulate food (8–20 μm in diameter) is pushed between the bases of the paragnaths by specialised brush like setae on the coxopodites of maxillae I. In both processes, all materials transferred to the mouth is entangled in secretions from the rosette glands of the paragnaths, resulting in a coherent bolus of material which is passed into the oesophagus by the posterior feeding process of the labrum. Direct examination of these processes and statistical analysis of their movements shows a strong correlation between movements of maxillae I, the paragnaths and labrum. Mandibular movements however, appear independent of these, suggesting that although penaeid prawns prefer to feed macrophagously they can efficiently ingest particulate food without the need of mandibular occlusion and undue energy expenditure.

GONOPODS OF THE MAJID CRAB CHIONOECETES OPILIO (O. FABRICIUS)

ABSTRACT To further elucidate the reproductive processes of the snow crab Chionoecetes opilio (O. Fabricius) the first and second gonopods of adult specimens were examined using scanning electron microscopy and histology. Surface features and setal types are described for both gonopods. The gonopods are highly modified compared to other brachyuran crabs and lower crustaceans. Suggestions for setal function are presented, based on size, orientation, location, fine structure, and cuticular insertion. Tubulation of the endopod is observed in both the first and second gonopods. Rosette glands are abundant in the basal half of the first gonopod, but are absent in the second gonopod. A duct network from the rosette glands terminates in cuticular pores that are restricted to the ejaculatory canal, indicating that the rosette glands function in copulation, probably contributing to the seminal fluids. A mechanism for transfer of seminal fluids is proposed, based on the relative sizes of the gonopods and the morphology of the second gonopod.

STRUCTURE AND FUNCTION OF THE REPRODUCTIVE SYSTEM OF THE SYMBIOTIC SPIDER CRAB INACHUS PHALANGIUM (DECAPODA: MAJIDAE): OBSERVATIONS ON SPERM TRANSFER, SPERM STORAGE, AND SPAWNING

The structure and function of the reproductive tracts of the spider crab Inachus phalangium were investigated, focusing on sperm transfer, sperm storage in the seminal receptacles, and spawning. Males produce and store spermatophores as well as part of the seminal fluid in the anterior and median vas deferens. The major part of the seminal fluid is produced and stored in the posterior vas deferens. Rosette glands fill the basal third of the first pleopods and open into pores on the pleopod tips. It is suggested that their secretions mix with seminal fluid during copulation and cause hardening of the seminal products. A male's ejaculate consists of sperm gel and a sperm packet formed by densely packed spermatophores. The seminal receptacle consists of a dorsal sperm storage and a ventral insemination chamber, separated by the muscular velum. The sperm storage chamber wall is lined with holocrine gland epithelium which secretes into the receptacle lumen. Shortly before spawning an oviduct opens ventrally into the insemination chamber, which is connected by the vagina with the sternum. During spawning some spermatophores at the ventral part of the lowest sperm packet are dissolved, and the sperm form a suspension in the insemination chamber, where passing oocytes are inseminated. The flexible vagina is opened for mating and spawning by muscular contractions. Females may store sperm for over 6 months and can fertilize up to 6 broods without remating.

Rosette glands in the gills of the grass shrimp Palaemonetes pugio. II. Premolt ductule reformation: Replacement of ciliary processes by cytoplasmic processes in relation to gland maturation.

The events associated with premolt reformation of the cuticularized ductule in the underdeveloped (immature) branchial rosette glands, which are common in the gills of small (14-18 mm, total length) grass shrimp, are described and contrasted with the events of ductule reformation in the fully developed (mature) resette glands most common in larger shrimp. In immature rosette glands, two ciliary processes emerge from each of the component secretory cells and ascend into the basal luminal region of the old ductule. Subsequently a new ductule is formed around the old ductule, and the ciliary processes disappear, either because of degeneration or retraction. The transitory ciliary processes appear to prevent the old ductule from collapsing during the formation of a new ductule. Such transitory ciliary processes, however, are not found in association with premolt ductule reformation in the mature rosette glands; in their place are seen a number of microvilli-like cytoplasmic processes, which emanate from the apices of the secretory cells and from the channels of the central cell. These cytoplasmic processes in mature glands, like the ciliary processes in immature glands, are transitory and appear to prevent the collapse of the old ductule. Cytoplasmic processes comparable to those in mature glands, but relatively few in number and originating only from the secretory cells, are seen together with ciliary processes in some immature glands. The relative abundance of cytoplasmic processes in the mature glands, coupled with the observation that transitory ciliary processes occur in immature glands but not in mature glands, suggests that, during glandular maturation, transitory ciliary processes are replaced by transitory cytoplasmic processes.

Rosette glands in the gills of the grass shrimp, Palaemonetes pugio. I. Comparative morphology, cyclical activity, and innervation.

Two types of exocrine rosette glands (called type A and type B), located in the gill axes of the grass shrimp Palaemonetes pugio, are described. The type A glands are embedded within the longitudinal median septum of the gill axes, whereas the type B glands typically project into the efferent hemolymph channels of the gill axes. Although both glands have certain common characteristics (i.e., a variable number of radially arranged secretory cells, a central intercalary cell, and a canal cell that forms the cuticular ductule leading to the branchial surface), they differ in the following respects. The type B gland is innervated, but the type A gland is not; axonal processes, containing both granular (ca. 900-1300 Å) and agranular (ca. 450-640 Å) vesicles, occur at a juncture between adjacent secretory cells and the central cell of the type B gland. The secretory cells of type A and type B glands differ in their synthetic potential and membrane specializations. These differences are more pronounced in well-developed, mature glands, most frequently encountered in larger (24-28 mm, total length) grass shrimp, than in the underdeveloped, immature glands that are most abundant in smaller (14-18 mm, total length) grass shrimp. Thus, in mature glands, the secretory cells of the type A rosette glands are characterized by extensive RER, abundant Golgi, and numerous secretory granules, whereas the secretory cells of the type B gland are characterized by extensively infolded and interdigitated basal plasmalemmas and by the presence of numerous mitochondria. In general, both types of glands exhibit increased secretory activity soon after ecdysis. The central and canal cells in both glands seem to have a role in the modification of the secreted materials. The possible functions assigned to the type A gland and the type B gland include phenol-oxidase secretion and osmoregulation, respectively.