Multicellular Glands Research Articles

The Status of Synstemon (Brassicaceae) and the Discovery of a Second Species

The taxonomic limits of Synstemon are established, and its relationship to Dontostemon is discussed. Synstemon lulianlianus, a new species from Gansu, is described and illustrated. Previously described taxa in Synstemon are reduced to synonymy of S. petrovii. The genus Synstemon was established by Botschantsev (1959) to include one species and two varieties. It was compared with Cymatocarpus O. E. Schulz and Arabidopsis Heynhold and was said to differ from these in having ciliate petal claws, connate and pubescent median filaments, and margined seeds. Synstemon is unrelated to Cymatocarpus or Arabidopsis, and it also differs from both by having flattened and strongly crisped instead of the rigid and straight trichomes, strongly differentiated instead of undifferentiated petal claws, and apiculate instead of obtuse anthers. Cymatocarpus also has yellow flowers, long setose trichomes, and submoniliform fruits, whereas Synstemon has lavender flowers, soft trichomes, and torulose fruits. In our opinion, Synstemon is unrelated to these genera. Botschantsev (1959) distinguished Synstemon from Dontostemon Andrzejowski ex C. A. Meyer because of the former's ciliate petal claws, veinless septa, and mucilaginous seeds, but a closer examination reveals that the difference in the fruit septum (veined vs. veinless) is unreliable, and most of the 10 species of Dontostemon have veinless septa. Synstemon differs in having pilose petal claws, entire stigmas, mucilaginous seeds, median stamens united only at the very base, terete replum, median nectaries present and confluent with the laterals, and flattened, strongly crisped trichomes, as well as in lacking the multicellular glands seen in some species of Dontostemon. By contrast, Dontostemon has glabrous filaments and petal claws, 2-lobed stigmas, nonmucilaginous seeds, median filaments united near to the apex, flattened replum, no median nectaries, straight or slightly twisted terete trichomes, and (in four species) well-developed multicellular glands. The two genera share many characters, and it appears that Synstemon is more closely related to Dontostemon than to any other Asian genus of Brassicaceae (Cruciferae). Because of fear that Synstemon might be considered a later homonym of Synostemon F. Miller, which is a synonym of Sauropus Blume of the Euphorbiaceae, Botschantsev (1980) proposed Synstemonanthus as a replacement of Synstemon. However, the pronunciations of the two are quite different, and we agree with Brummitt (1992) in recognizing Synstemon instead of Synstemonanthus. The presence in Synstemon of pilose petal claws and filaments is unique among all of the Old World Brassicaceae. This feature clearly supports the maintenance of the genus as independent of Dontostemon, as well as those Eurasian genera with connate median filaments. Pubescent petal claws and/or filaments are known among several genera in the New World, including the North American Stanleya Nuttall, Warea Nuttall, Rollinsia Al-Shehbaz, and a species of Dryopetalon A. Gray (AlShehbaz, 1982, 1985; Payson, 1923; Rollins, 1939, 1993), as well as the South American Chilocardamum 0. E. Schulz, Pterygiosperma O. E. Schulz, Sarcodraba Gilg & Muschler, Sisymbrium subscandens Spegazzini, and Trichotolinum O. E. Schulz (Boelcke & Romanczuk, 1984; Schulz, 1924, 1936). Synstemon remained monotypic until An (1981) added S. linearifolius An (as linearifolia) and S. petrovii var. xinglongnicus An (as xinglongnica). These two new taxa, along with Botschantsev's NOVON 10: 99-103. 2000. This content downloaded from 157.55.39.183 on Thu, 26 May 2016 05:36:53 UTC All use subject to http://about.jstor.org/terms

A Reconsideration of the Genus Eurycarpus (Brassicaceae)

The Himalayan (Tibet and adjacent Kashmir) endemic Eurycarpus is recognized, and the characters separating its two species from Christolea, Desideria, and Parrya are discussed. The new combination E. marinellii is proposed, and Christolea longmucoensis is reduced to synonymy of E. marinellii. In establishing the genus Eurycarpus, Botschantsev (1955) separated it from what was then the invalidly published genus Ermania Chamisso by the biseriate instead of uniseriate seeds, broadly lanceolate instead of linear fruits, entire instead of dentate leaves, and leafless instead of leafy scapes. However, he probably compared only the type species of both genera because most of these alleged differences do not hold if one compares Eurycarpus with the ten species that Botschantsev recognized in Ermania. Eight of the ten species of Ermania are presently assigned to Desideria Pampanini, and the remaining two, including the type of Ermania, belong to the earlier published Melanidion E. L. Greene. For a discussion on the invalidity of Ermania and the generic limits of Desideria and Melanidion, see Al-Shehbaz (2000). Although the type species of Eurycarpus was originally described in Parrya R. Brown, the two genera are unrelated. Eurycarpus has at least some of the trichomes forked, nonsaccate lateral sepals, terete replums, wingless seeds, and entire stigmas, and it lacks the multicellular glands. By contrast, Parrya has exclusively simple trichomes or the plants are glabrous, strongly saccate lateral sepals, flattened replums, winged seeds, prominently 2lobed stigmas with decurrent, connivent lobes, and often multicellular glands. Desideria differs from Eurycarpus by having dentate, often palmately veined leaves, prominently veined valves with well-developed marginal veins, linear to linear-lanceolate fruits rectangular in cross section, valve apices persistently united with replum, obsolete styles, and 2-lobed stigmas. Eurycarpus has entire, pinnately veined leaves, obscurely veined valves without marginal veins, oblong, elliptic, ovate-oblong, or ovate-lanceolate fruits narrowly elliptic in cross section, valve apices readily free from the replum at dehiscence, welldefined subconical styles, and minute, entire stig-

Structure and development of the pitchers from the carnivorous plantNepenthes alata (Nepenthaceae)

The pitchers of the tropical carnivorous plant Nepenthes alata are highly specialized organs for the attraction and capture of insects and absorption of nutrients from them. This study examined the structure and development of these pitchers, with particular focus on the nectaries and digestive glands. Immature pitchers developed at the tips of tendrils and were tightly sealed by a lid structure that opened during the end of pitcher elongation. Opened pitchers exposed a ridged peristome containing large nectaries. Like other members of the genus, a thick coating of epicuticular waxy scales covered the upper one-third of the pitcher. Scattered within this zone were cells resembling a stomatal complex with a protruding ridge. Cross sections showed that this ridge was formed by asymmetric divisions of the epidermal cells and lacked an underlying pore. The basal region of the trap had large multicellular glands that developed from single epidermal cells. These glands were closely associated with underlying vascular traces and provided a mechanism for supplying fluid to closed immature pitchers.

Structure, function, and evolution of the oviducts of squamate reptiles, with special reference to viviparity and placentation

In lizards and snakes, the oviducts function in fertilization, sperm storage, egg transport, eggshell deposition, maintenance of the early embryo, and expulsion of the egg or fetus. In viviparous forms they also contribute to placentae responsible for gas exchange and nutrient provision to the fetus. Dissections of species of 30 genera coupled with data from the literature indicate that squamate oviducts vary interspecifically in seven macroscopic features, including the extent and nature of regional differentiation, vascular supply, topographic asymmetry, number of oviducts, vaginal pouches, and relationship to the cloaca. The uterus, infundibulum, and vagina differ histologically in their epithelia, glands, and myometrial layers. Seasonal cyclicity occurs in all three oviductal regions, most prominently in the uterus, and is under endocrinological control. Regional and cytological specializations reflect the diverse functions performed by the oviduct. Definitive evidence for oviductal albumen production and egg resorption is lacking. In viviparous squamates, three uterine specializations may facilitate maternal–fetal gas exchange: an attenuated epithelium, reduced uterine glands (and a reduced shell membrane), and increased vascularization. Contrary to previous reports, pregnant uteri show no epithelial erosion or capillary exposure. Specializations for nutrient provision to the fetus include mucosal hypertrophy, enlarged glandular epithelia, and multicellular glands whose secretions are absorbed by the chorioallantois. Comparisons with other amniotes indicate that squamates inherited the oviduct as an organ with capabilities for egg uptake and transport, fertilization, eggshell deposition, and oviposition. Other features have evolved convergently among squamates: infundibular sperm receptacles, unilateral oviduct loss, uterine gestation, placentation, and specializations for placentotrophy. Cladistic analysis indicates that oviductal features associated with deposition of tertiary egg investments in reptiles reflect evolutionary convergence as well as secondary simplification, rather than a unidirectional trend towards increased specialization. J. Exp. Zool. 282:560–617, 1998. © 1998 Wiley-Liss, Inc.

Structure, function, and evolution of the oviducts of squamate reptiles, with special reference to viviparity and placentation

In lizards and snakes, the oviducts function in fertilization, sperm storage, egg transport, eggshell deposition, maintenance of the early embryo, and expulsion of the egg or fetus. In viviparous forms they also contribute to placentae responsible for gas exchange and nutrient provision to the fetus. Dissections of species of 30 genera coupled with data from the literature indicate that squamate oviducts vary interspecifically in seven macroscopic features, including the extent and nature of regional differentiation, vascular supply, topographic asymmetry, number of oviducts, vaginal pouches, and relationship to the cloaca. The uterus, infundibulum, and vagina differ histologically in their epithelia, glands, and myometrial layers. Season cyclicity occurs in all three oviductal regions, most prominently in the uterus, and is under endocrinological control. Regional and cytological specializations reflect the diverse functions performed by the oviduct. Definitive evidence for oviductal albumen production and egg resorption is lacking. In viviparous squamates, three uterine specializations may facilitate maternal-fetal gas exchange: an attenuated epithelium, reduced uterine glands (and a reduced shell membrane), and increased vascularization. Contrary to previous reports, pregnant uteri show no epithelial erosion or capillary exposure. Specializations for nutrient provision to the fetus include mucosal hypertrophy, enlarged glandular epithelia, and multicellular glands whose secretions are absorbed by the chorioallantois. Comparisons with other amniotes indicate that squamates inherited the oviduct as an organ with capabilities for egg uptake and transport, fertilization, eggshell deposition, and oviposition. Other features have evolved convergently among squamates: infundibular sperm receptacles, unilateral oviduct loss, uterine gestation, placentation, and specializations for placentotrophy. Cladistic analysis indicates that oviductal features associated with deposition of tertiary egg investments in reptiles reflect evolutionary convergence as well as secondary simplification, rather than a unidirectional trend towards increased specialization.

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.

Ontogeny of the digestive tract during larval development of yellowtail flounder: a light microscopic and mucous histochemical study

The histological development and mucous histochemistry of the alimentary tract in larval yellowtail flounder were studied using light microscopy. Samples were taken when the larvae were first offered food at 3 days post-hatch, then at 7, 10, 29, 36, and 46 days post-hatch, at which time they were metamorphosing. Regional partitioning of the digestive tract into the buccal cavity, pharynx, oesophagus, post-oesophageal swelling (PES), intestine, and rectum was complete by day 10. Goblet cells were present only in the buccal cavity, pharynx and intestine by day 7, but increased in number and distribution as development continued. By day 29, the posterior zone of the oesophagus had a marked increase in goblet cell density and mucosal folding. At the transition from oesophagus to PES/stomach stratified epithelium with goblet cells changed abruptly to a columnar epithelium with no goblet cells. Multicellular glands in the PES of 36-day larvae allowed it to be defined as a stomach. The distinct brush border of columnar epithelium and the presence of goblet cells characterize the intestine and rectum. All goblet cells throughout the digestive tract were strongly positive for acid mucins as was the luminal layer of the stratified epithelia lining the buccal cavity, pharynx and oesophagus. The PES/stomach epithelium stained weakly for neutral mucins. No mucin staining was associated with the gastric glandular epithelium. The brush borders of the intestine and rectum were strongly positive for combinations of neutral and acid mucins.

Glandular hairs in the genus Drosera (Droseraceae)

On the leaves and sepals of 52 species, representing all sections of the genusDrosera except one, 14 different types of glandular hairs were found: two-celled papillae, peltate scales, several types with unbranched, bi- or multiseriate stalk with a two- or multicellular gland, and one type with a multiseriate stalk and a two-armed gland. The combination of these hairs and the presence of non-glandular hairs confirm the actual classification of the genus. In combination with simple morphological characters (e.g., the type of insertion of the petiole) glandular hairs facilitate the identification of species even in the pharmaceutically important cut crude drug.

Histological and chemical comparison of triterpene and phenolic deterrent contents of juvenile shoots of Betula species

Defence-related epithelial structures of juvenile stems and their phytochemistry were compared between six woody species of Betula from different geographical areas. The shoots of B. pendula, B. papyrifera, B. platypylla and B. ermanii are covered by resin droplets secreted by multicellular peltate glands. The seedlings of B. papyrifera and B. pubescens are covered with long epithelial hairs. Closer topical examination also revealed smaller glands on B. papyrifera and B. pubescens. The glands of B. ermanii are oval while the other species have a round shape. Phenol-specific histochemical staining indicated phenolic compounds in the cells in active glands of the resinous birches, but not in those of the pubescent birches. The epithelial hairs were strongly positive to the phenol stain. Analysis of the triterpenoids (3α- and 3β-papyriferic acid and pendulic acid) and a phenolic (platyphylloside) deterrent indicated that the morphological differences are accompanied by chemical ones. Pendulic acid was the main triterpene in B. ermanii instead of the 3α-papyriferic acid of the other resinous species. Concentrations of the triterpenes ranged from about 0.3 to 12 mg/g, while the platyphylloside level was around 0.5 mg/g in all of them. Some triterpenes were also detected in B. papyrifera, but none in B. pubescens. The former contained only about 0.05 mg/g of platyphylloside, but B. pubescens contained 4 mg/g of this compound.

The variability of the hypericin content in the regenerants of Hypericum perforatum

AbstractThe hypericin content of in vitro regenerated plants of Hypericum perforatum L. was determined by spectrophotometry. A significant variability of some of the morphological characters, of the biomass production and the hypericin formation was found within the somaclones of the same genetic origin and among the regerants of different genotypes. The concentration of BAP which promoted the shoot differentiation did not affect the hypericin content and the gland density. New information on the ultrastructure of hypericin‐containing multicellular glands is presented here.

Functional morphology of the mammiliform penial glands ofLittorina saxatilis (Gastropoda)

The functional morphology of the mammiliform penial glands ofLittorina saxatilis has been investigated with both light and electron microscopy. These penial glands line the ventral edge of the penis and orient with the female mantle during copulation. Secretions are released from the penial glands to this interface where they probably function in adhesion. The penial gland secretions comprise heterogeneous granules as well as apocrine and mucous secretions. The heterogeneous granules are produced in separate multicellular glands arranged in a series of lobes that lie outside a thick smooth muscle layer enclosing the lumen. Each glandular lobe is surrounded by a thin layer of smooth muscle. Secretions are transported in individual cellular processes that pass through the thick smooth muscle layer and empty into the lumen. Surrounding the lumen is an epithelium containing apocrine secretory cells as well as occasional goblet-type, mucous cells. The combined action of the muscles forces secretions out of the lumen through the penial papilla, onto the external surface of the mammiliform penial gland. Longitudinal muscles extend into the penial papilla enabling its protrusion or retraction. Retraction of the penial papilla following secretion release is thought to create negative pressure beneath the penial gland producing suction adhesion. The visco-elastic properties of the penial gland secretion are qualitatively different from foot mucus and may represent specialization to an adhesive function.

Collagen type conservation during metamorphic repatterning of the dermal fibers in salamanders

The orientation of the fibers in the dermis of the tiger salamander, Ambystoma tigrinum, undergoes a dramatic repatterning at metamorphosis. The pre-metamorphic, larval dermis is a tight layer composed of crossed fibers that wind helically around the trunk. This condition is retained by neotenic adults which do not undergo metamorphosis. In contrast, the neotenic adults which do not undergo metamorphosis. In contrast, the metamorphosed adult dermis consists of a superficial, loose network of fibers invested with large multicellular glands--the stratum spongiosum--and a deeper tight layer of fibers--the stratum densum. However, unlike the crossed fibers of the pre-metamorphic dermis, there is no preferred orientation to the fibers in either layer of the post-metamorphic dermis. In order to evaluate whether these two distinctly different fiber patterns are constructed from biochemically similar fibers, the collagen types present in the pre- and post-metamorphic dermis were determined using SDS-polyacrylamide gel electrophoresis. Type I collagen is the predominant collagen of the dermis and the same major collagen types are present for all individuals, whether pre- or post-metamorphic. Thus, the major types of collagen that compose the dermal fibers do not change during metamorphic repatterning of the dermis.

Development and structure of resin glands on tissues of Betula pendula Roth, during growth

summary Betula pendula Roth, and a number of other species of the genus are known to excrete resinous chemicals on juvenile shoots and twigs as deterrents against herbivores. The present studies show that the resin is produced by specific multi cellular glands that are of the same ontogenetic origin as the glands covering developing tissues in buds during winter dormancy. It was possible to deduce from observations over a season that the resin production may be regulated at two levels. Density of the glands on the shoot surface is determined at the time of tissue differentiation in the beginning of primary growth, and the excretory activity is related at least in part to gland size. Towards the end of the growth period the cores of glands were gradually filled with bark cells and the interior of the columnar excretory cells of their epidermis appeared pale and hollow instead of the dense blue in younger glands, when stained with haematoxylin. The excretion of resin by B. pendula appears to be a primary defence mechanism that is active during that part of the season, when apical growth of a juvenile shoot takes place.

Hair morphology and systematics ofPhysalis (Solanaceae)

Hair morphology was exammed on developing seedlings and mature plants of ten species from five of seven series inPhysalis. The taxonomic importance of hair development and the distribution of hair types then was evaluated with respect to other comparative data. Two classes of hair types were observed, as found in earlier investigations ofSolanum andRhododendron. The first hair class comprises a sequence from unbranched hairs to dendroid-stelliform hairs. Hairs of this class show considerable variability among taxa in size, presence or absence of glandular tips, and presence and degree of branching, and so were useful in making taxonomic comparisons. The second hair class consists of short hairs, each tipped with a multicellular gland. This second hair class was not useful taxonomically because of its lack of variability in morphology and its often rare occurrence on a plant. The taxa studied exhibit distinctive trichome features which serve to distinguish series and, in some cases together with other data, provided new insight into previously enigmatic species relationships.

A revision of the genus <i>Prionanthium</i> (Poaceae : Arundineae)

Priononanthium revised and three species are recognized. All three species have a chromosome number of n =7. The genus is unual. in having multicellular, secretory glands on the glumes and a wide range of inflorescence types. Priononanthium is considered to be arundinoid on the basis of its leaf anatomy, ciliate ligule, spikelet morphologyand less strongly, chromosome number. Its chromosome number, multicellular glands, two florets per spikelet, type of palea and rachilla extension relate it more closely to Pentaschistis than to any other extant arundinoid genus. A fully illustrated taxonomic account is presented.

INTERNAL MORPHOLOGY RELATED TO TUBE-BUILDING IN THE MEIOBENTHIC COPEPOD PSEUDOSTENHELIA WELLSI

ABSTRACT Pseudostenheliawellsi Coull and Fleeger, a meiobenthic harpacticoid copepod, lives in selfconstructed tubes in muddy, estuarine sediments. Tubes are composed of sediment bound with acid mucopolysaccharide as shown by a positive reaction with alcian blue and periodic acid-Schiff reagent. The purpose of this study was to detail structural specializations in P. wellsi as related to secretion and storage of tube-building substances. Cuticular pores are located in the ventral cephalothorax, on the first urosomal segment (just anterior to the fifth leg), the anal segment, and on the caudal rami. Light level histochemistry shows that storage sites of mucin coincide with the pores and are found in the caudal rami, fifth leg area, and ventral cephalothorax. Massive stores of lipid-like material (corresponding to highly visible autofluorescent areas in living specimens) are also associated with pores and mucin. The largest reservoir of the lipid-like material is in the urosome surrounding the gut just anterior to the caudal rami. The function of the lipid-like material is unknown, but it is not incorporated in the matrix of the secreted tube. Transmission electron microscopy revealed that the mucin and lipid-like materials are secreted by multicellular and unicellular glands, respectively. The major mucin-secreting cells are found in the upper region of the caudal rami, while the largest gland secreting the lipid-like material is in the mid-urosome.

Grindelia camporum: Potential cash crop for the arid southwest

Grindelia camporum is a conspicuously resinous, herbaceous perennial found in the Central Valley area of California. The resin is produced in multicellular glands, which occur on the surfaces of stems, leaves, and involucres. The resin is composed of grindelic acid and several of its derivatives. These labdane diterpenes are similar to the resin acids that constitute rosin, a principal product of the naval stores industry, and it seems likely that resin extracted from Grindelia would have uses similar to those of rosin. If improved varieties of Grindelia camporum can be developed that yield a higher proportion of resin, this species would be suitable for domestication as a new crop for arid lands.

Electric current flow in a two-cell preparation from Chironomus salivary glands.

Conventional micro-electrode techniques were used to study the passive electrical properties of salivary glands from Chironomus nuditarsis insect larvae of the fourth instar stage. Linear cable analysis performed on intact glands revealed the following constants: axial intracellular resistance, Ri = 2730 omega cm; membrane resistance per unit apparent cylindrical area, Rm = 1350 omega cm2; membrane capacitance per unit apparent cylindrical area, Cm = 17.6 microF cm-2. The multicellular glands were reduced to intact two-cell preparations by destroying neighbouring cells mechanically. Each cell of a coupled cell pair was impaled with two micro-electrodes, one to pass rectangular current pulses and the other to monitor the resulting voltage deflexions. Internal consistency tests revealed that the experimental data under steady-state conditions may be described accurately by an equivalent circuit consisting of a delta configuration of three resistive elements: the resistances of the non-junctional membrane of cell 1 and cell 2 (r1 and r2), and the resistance of the gap junctional membrane connecting the two cells (rg). The current-voltage relation of the non-junctional membrane was found ohmic over a membrane potential ranging from -40 mV to + 10 mV. The mean value of Rm was 2020 omega cm2. The resistance function of the gap junctional membrane was also ohmic. There was no dependence of gap junctional resistance on voltage or direction of current flow, at least over the relatively narrow range of potentials tested (approximately +/- 10 mV). Individual values of rg varied from 20 to 3800 k omega, with an over-all mean of 1100 k omega. The lower values are thought to represent the physiological state of cellular coupling, whereas the higher ones may reflect partial uncoupling caused by local damage. The proposed cell pair is a suitable preparation for studying problems related to intercellular coupling.

Secretory characteristics of the rat nasal glands.

The distribution of the secretory elements in the nasal mucosa and the nature of their secretory products were studied with the use of light- and electronmicroscopical techniques and radioisotopes. Unicellular glands showed a varying density at different sites of the nasal cavity and their distribution appeared to depend on environmental conditions. In contrast to the human nose, the multicellular glands are concentrated in two large glandular masses, which appeared to consist of various glands. They differed in producing either a glycoprotein or a nonglycoprotein containing secretion, in the character of the secretory granules and in the nature of the glycoproteins. The secretions are drained at different sites in the nasal cavity. Uptake and release of radioisotopes suggest a rather high activity of the glandular tissue.

ULTRASTRUCTURE AND FUNCTIONAL MORPHOLOGY OF FEEDING AND ASSOCIATED APPENDAGES IN THE TROPICAL FRESH-WATER SHRIMP ATYA INNOCOUS (HERBST) WITH NOTES ON ITS ECOLOGY

ABSTRACT Atya innocous (Atyidae) occurs in permanent and temporary fresh-water streams in Panama. Its microhabitat distribution depends in part on the presence of congeners. The propodus and dactylus of each cheliped of A. innocous bear about 300 setae modified for specific functions in food collection. These setae may be divided into three basic types: chemoreceptors, scrapers, and filtering setae. The latter two types also function as mechanoreceptors. The cheliped setae are probably extended by an increase in hemocoelic pressure, producing an efficient filtering fan. Mechanosensory and chemosensory bipolar neurons innervate the cheliped setae, presumably providing the shrimp with the ability to detect current velocity, particulate load, and quality of the food source. The external morphology and ulrastructure of these sensilla are described. No dually innervated receptors (mechanochemoreceptors) were found. In addition to food collection and sensory functions, the pereiopods are used to groom body parts and brooded embryos. Super-8 eine films show the important role mouthparts play in grooming. The third maxillipeds groom the antennae and antennules, while the ultimate segment of the second maxillipeds frees lodged debris from the chelipeds. The dactylar pectinate comb of the fifth pereopod grooms the dorsal surface of the abdomen and pleopods. Scanning electron microscopy showed pores in the cuticle leading to unicellular and multicellular glands within the epidermis. Three gland types were observed and their respective functions are described. Adaptations for a lotic habitat seem to be important to species of Atya, which have a wide array of morphological modifications for life in running water.