Nine new species of Dichogaster (Oligochaeta, Megascolecidae) from Guadeloupe (French West Indies)

Nine species belonging to two distinct groups within the genus Dichogaster Beddard, 1888 are described from material collected on the volcanic section of the island of Guadeloupe. The species Dichogaster arborea, D. caesitifusca, D. callaina, D. girija and D. basseterrensis all inhabit the leaf tanks of bromeliads and share the following anatomical characteristics: spermathecal pores on the trailing edges of segments, spermathecal axis differentiated into ampulla, internally fluted central chamber and duct, penial setae long and slender, testes and funnels free, prostomium undivided or divided by two grooves, simple single typhlosole and a pair of dorsal caeca on the mid-intestine. Dichogaster athena also inhabits bromeliads, but lacks the above characteristics and male reproductive organs, and is more similar to the remaining species. The three remaining species, D. guadeloupensis, D. matoubensis and D. musciphila , with lateral typhlosoles, no intestinal caeca, simpler spermathecal structure, prostomiums divided by a single groove and short penial setae, all inhabit soils of montane forests. The division of Dichogaster based on muscularity of the proventriculus wall is shown to be unsupportable, since thickness of the wall is size-related.     

Level,content, and caloric equivalents of the lipid,carbohydrate, and protein in the body components of Luidia clathrata (echinodermata: asteroidea: platyasterida) in Tampa bay

The body components of the primitive platyasterid starfish, Luidia clathrata (Say) have been characterized according to season, reproductive, and nutritional condition. The animal has been ‘reconstructed’ in terms of the wet and dry weights, the weight of organic matter, and the caloric equivalents of the body components in early summer (when there are no gonads and the pyloric caeca are small), in autumn (just prior to initiation of gonadal development and at maximal caeca size), and in early spring (at maximal gonad size). The body wall is always the most significant component in terms of wet and dry weights. In terms of organic matter and calories, the pyloric caeca are the most significant compartment in the fall and, together with the gonads, in the spring. On starvation for one month, the decrease in the size of the pyloric caeca is calculated to have produced 2.048 kcal. The energy requirement over the period, calculated from Q_o2 values, is 2.112 kcal. There was no change in biochemical composition of the pyloric caeca with starvation, suggesting that energy production came about through cell destruction rather than preferential utilization of cellular nutrient stores. Lack of extreme change in the composition of the pyloric caeca with size through the year also suggests that energy deposition in the organ is primarily by change in cell number and not by cell size.     

The ontogeny of shell secretion in Terebratalia transversa (Brachiopoda, Articulata). II. Formation of the protegulum and juvenile shell

The fine structure of the shell and underlying mantle in young juveniles of the articulate brachiopod Terebratalia transversa has been examined by electron microscopy. The first shell produced by the mantle consists of a nonhinged protegulum that lacks concentric growth lines. The protegulum is secreted within a day after larval metamorphosis and typically measures 140-150 micron long. A thin organic periostracum constitutes the outer layer of the protegulum, and finely granular shell material occurs beneath the periostracum. Protegula resist digestion in sodium hypochlorite and are refractory to sectioning, suggesting that the subperiostracal portion of the primordial shell is mineralized. The juvenile shell at 4 days postmetamorphosis possesses incomplete sockets and rudimentary teeth that consist of nonfibrous material. The secondary layer occuring in the inner part of the juvenile shell contains imbricated fibers, whereas the outer portion of the shell comprises a bipartite periostracum and an underlying primary layer of nonfibrous shell. Deposition of the periostracum takes place within a slot that is situated between the so-called lobate and vesicular cells of the outer mantle lobe. Vesicular cells deposit the basal layer of the periostracum, while lobate cells contribute materials to the overlying periostracal superstructure. Cells with numerous tonofibrils and hemidesmosomes differentiate in the outer mantle epithelium at sites of muscle attachments, and unbranched punctae that surround mantle caeca develop throughout the subperiostracal portion of the shell. Three weeks after metamorphosis, the juvenile shell averages about 320 micron in length and is similar in ultrastructure to the shells secreted by adult articulates.     

臭腹腺蝗（直翅目：锥头蝗科）胃盲囊的异速生长和功能特性

通过对臭腹腺蝗Zonocerus variegatus（直翅目：锥头蝗科）6个若虫期及成虫期主消化道和胃盲囊分段进行解剖和测量,对其胃盲囊的异速生长和功能特性进行了研究。结果表明,胃盲囊和主消化道的生长是不同速的。胃盲囊前段较后段生长速率更高,但两者生长速率显著相关。消化道和胃盲囊的平均长度亦显著相关。随年龄增长,消化道的生长速率降低,而胃盲囊的生长速率上升。与胃盲囊前段功能相同,胃盲囊后段亦具有消化和吸收功能,被认为能在营养缺乏的旱季起到增加肠胃吸收面的功能。     

双蜺腔蚓的生殖器官多态现象（寡毛纲：巨蚓科）

报道腔蚓属Ｍｅｔａｐｈｉｒｅ蚯蚓Ｍｅｔａｐｈｉｒｅｆａｎｇｉ（Ｃｈｅｎ,１９３６）及Ｍｅｔａｐｈｉｒｅｂｉｐａｐｉｌｌａｔａ（Ｃｈｅｎ,１９３６）应作为Ｍｅｔａｐｈｉｒｅｂｕｃｃｕｌｅｎｔａ（Ｇａｔｅｓ,１９３５）的同种异名,并记述该种的生殖器官多态现象。     

The relationship of pores and mammillae on the inner surface of the eggshell of the alligator (Alligator mississippiensis)

The morphology of the eggshell of the alligator, Alligator mississippiensis, is similar to that of birds. In many avian species there is a positive linear correlation between the numbers of pores and mammillae on the inner surfaces of eggshells, indicating that the distribution and density of mammillae may determine the porosity of the shell. It is not known, however, if a relationship exists between pores and mammillae on the shell of the alligator. Using a scanning electron microscope, we counted pores and mammillae on the inner surfaces of pieces of shell from the middle of fertile and infertile eggs from wild and captive, pen-reared alligators. Data were analyzed by ANOVA, Duncan's multiple range tests and linear regression equations. Results demonstrate a positive linear correlation between the numbers of pores and mammillae on the shells of unincubated fertile and infertile eggs from wild and captive alligators; however, there is no correlation between pores and mammillae on shells of eggs that were incubated for 55 days. It is suggested that initially the porosity of the eggshell of the alligator is related to the density of mammillae on the inner surface of the shell and that erosion of the shell during incubation destroys the original relationship between pores and mammillae.     

Structural analysis of CsoS1A and the protein shell of the Halothiobacillus neapolitanus carboxysome

The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO₂ fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/oxygenase (RuBisCO) and carbonic anhydrase. The outer shell of the carboxysome is reminiscent of a viral capsid, being constructed from many copies of a few small proteins. Here we describe the structure of the shell protein CsoS1A from the chemoautotrophic bacterium Halothiobacillus neapolitanus. The CsoS1A protein forms hexameric units that pack tightly together to form a molecular layer, which is perforated by narrow pores. Sulfate ions, soaked into crystals of CsoS1A, are observed in the pores of the molecular layer, supporting the idea that the pores could be the conduit for negatively charged metabolites such as bicarbonate, which must cross the shell. The problem of diffusion across a semiporous protein shell is discussed, with the conclusion that the shell is sufficiently porous to allow adequate transport of small molecules. The molecular layer formed by CsoS1A is similar to the recently observed layers formed by cyanobacterial carboxysome shell proteins. This similarity supports the argument that the layers observed represent the natural structure of the facets of the carboxysome shell. Insights into carboxysome function are provided by comparisons of the carboxysome shell to viral capsids, and a comparison of its pores to the pores of transmembrane protein channels.     

Structural Analysis of CsoS1A and the Protein Shell of the Halothiobacillus neapolitanus Carboxysome

The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO₂ fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/oxygenase (RuBisCO) and carbonic anhydrase. The outer shell of the carboxysome is reminiscent of a viral capsid, being constructed from many copies of a few small proteins. Here we describe the structure of the shell protein CsoS1A from the chemoautotrophic bacterium Halothiobacillus neapolitanus. The CsoS1A protein forms hexameric units that pack tightly together to form a molecular layer, which is perforated by narrow pores. Sulfate ions, soaked into crystals of CsoS1A, are observed in the pores of the molecular layer, supporting the idea that the pores could be the conduit for negatively charged metabolites such as bicarbonate, which must cross the shell. The problem of diffusion across a semiporous protein shell is discussed, with the conclusion that the shell is sufficiently porous to allow adequate transport of small molecules. The molecular layer formed by CsoS1A is similar to the recently observed layers formed by cyanobacterial carboxysome shell proteins. This similarity supports the argument that the layers observed represent the natural structure of the facets of the carboxysome shell. Insights into carboxysome function are provided by comparisons of the carboxysome shell to viral capsids, and a comparison of its pores to the pores of transmembrane protein channels.     

臭腹腺蝗（直翅目：锥头蝗科）消化道对食物储存、消化和吸收相适应的显微结构

显微观察发现臭腹腺蝗Zonocerus variegatus（直翅目：锥头蝗科）嗉囊、中肠和后肠的肠壁结构有所不同。嗉囊为空时纵向折叠。中肠上皮层的厚度随龄期有明显变化,1龄和2龄时明显大于3龄、4龄和5龄。后肠具有帮助消化和吸收的功能。     

Structure of the shell and tertiary membranes of eggs of softshell turtles (Trionyx spiniferus)

Eggs of the turtle Trionyx spiniferus are rigid, calcareous spheres averaging 2.5 cm in diameter. The eggshell is morphologically very similar to avian eggshells. The outer crystalline layer is composed of roughly columnar aggregates, or shell units, of calcium carbonate in the aragonite form. Each shell unit tapers to a somewhat conical tip at its base. Interior to the crystalline layer are two tertiary egg membranes: the outer shell membrane and the inner shell membrane. The outer shell membrane is firmly attached to the inner surface of the shell, and the two membranes are in contact except at the air cell, where the inner shell membrane separates from the outer shell membrane. Both membranes are multi-layered, with the inner shell membrane exhibiting a more fibrous structure than the outer shell membrane. Numerous pores are found in the eggshell, and these generally occur at the intersection of four or more shell units.     

Fine Structure of the Shell Wall in the Soil Testate Amoeba Cyclopyxis kahli (Rhizopoda)1

The common soil testate amoeba, Cyclopyxis kahli, is capable of building a complete organic shell when grown in culture in the absence of agglutinate material. Such shells are morphologically similar to agglutinate shells except in the structure and diameter of the aperture. Chemical analysis of organic shells suggests that the main inorganic elements present are calcium and iron. Comparisons are made with similar analyses of organic shells from other agglutinate species. This is the first report of a significant change in shell architecture due to agglutinate material.     

Body volumes and internal space constraints in articulate brachiopods

Brachiopods were once dominant in all the oceans of the world. but their distributions are non more restricted. There are few species which are found in shallow warm habitats and these are predominantly small. They have exceptionally low metabolic rates and exhibit low energy lifestyles. The majority of living articulate brachiopods are punctate (possessing mantle extensions. or caeca. which traverse the shell). Evidence produced hei-e suggests that the evolution of these phenomena may have been strongly affected by architectural constraints placed on articulate brachiopods by the use of the lophophore for feeding and respiration. They are essentially space limited because of the large volume needed for this organ. In some punctate brachiopods over 75% of their total body volume may be occupied by the lophophore and mantle cavity. This figure is only 60% in an impunctate (no caeca) species and may be only 20% in bivalve molluses. The implications are that caeca evolved to reduce pressure on space requirements, that maximum sizes may be set by the scaling patterns of space allocation and metabolic efficiency is a consequence of space constraints. Current distribution patterns may be strongly affected by the low metabolism and low energy lifestyles. The relative success of small brachiopods in warm shallow seas may have been facilitated by the scaling patterns of space allocations which show small specimens to have similar mantle cavity volumes to bivalve molluscs.     

Morphology of the digestive tract of the Whitemouth croaker Micropogonias furnieri (Desmarest, 1823) (Perciformes: Sciaenidae)

Studies have shown the feeding diversity of teleostean fish, which is conditioned by environmental characteristics or the biology of the different species. Analysis on the morphology of the digestive system (DS) of fish made it possible for researchers to know the food regimen of several species at different stages of life. On the other hand, it is known that food habits may lead to morphological changes in the DS the same way that different food habits may be imposed by morphological limitations of this system. Among the species of greater commercial importance in Brazil, Micropogonias furnieri is highly representative of fish in south‐eastern Brazil. Therefore, the objective of this study was to analyse the morphology of the DS of M. furnieri. Results on the morphology of the DS observed in this study were similar to the patterns determined for the morphology of teleostean fish. In this study, it was observed that the DS of the Whitemouth croaker is directly related with the shape of the peritoneal cavity; these fish showed oesophagus, stomach, pyloric caeca and intestines. The pyloric caeca showed morphological adaptations in relation to sexual maturation, with well‐developed caeca found in sexually mature animals.     

Histological description of the midgut and the pyloric valve of Tropidacris collaris (Stoll, 1813) (Orthopetera: Romaleidae).

The present research describes the histology of the midgut, gastric caeca, and pyloric valve of Tropidacris collaris (Stoll, 1813), (Orthopetera: Romaleidae). We used light microscopy, staining (Gomori's trichrome and periodic acid-Schiff (PAS)), and a routine histological analysis method (hematoxilin-eosin). The insects were obtained from, and also bred in, the Laboratory of Entomology, Department of Biology, of the Rural Federal University of Pernambuco (UFRPE). The collected material was fixed in alcoholic Botüin and embedded in paraplast. The results demonstrated that the midgut wall is composed of an inner epithelial layer and two outer layers of striate muscles: one internal (circular) and the other external (longitudinal), with connective tissue between the muscle fibers. The epithelium is single-layered, with two cell types: regenerative and elongated columnar. The gastric caeca presents muscle layers similar to those of the midgut. Simple columnar epithelium lines the gastric caeca, which presents villi and projects towards the lumen. The pyloric valve is of striate muscle tissue, covered by a single epithelial-cell layer.     

Description of a new blood-fluke,Cruoricola lates n. g., n. sp. (Digenea: Sanguinicolidae), from sea-bass Lates calcarifer (Bloch, 1790) (Centropomidae)

A new blood-fluke, Cruoricola lates n. g., n. sp., is described from sea-bass Lates calcarifer cultured in Malaysia. It is also found in Thailand and Australia. All fish examined over 15 cm in length were infected in the type-locality. This sanguinicolid is differentiated from other genera by: the spherical seminal vesicle; the large, single testis extending beyond the intestinal caeca; the medial, bi-lobed ovary; and the single column of sub-marginal, laterally directed, evenly spaced spines. It has separate genital pores which are close together. Adults are found predominantly in the mesenteric venules of the venous circulation. Juveniles are commonest in the caudal kidney.     

Ultrastructure of the digestive tract in Acarus siro (Acari: Acaridida)

The gut of the mite Acarus siro is characterized on the ultrastructural level. It consists of the foregut (pharynx, esophagus), midgut (ventriculus, caeca, colon, intercolon, postcolonic diverticula, postcolon), and hindgut (anal atrium). The gut wall is formed by a single-layered epithelium; only regenerative cells are located basally and these have no contact with the lumen. Eight cell types form the whole gut: (i) simple epithelial cells forming fore- and hindgut; (ii) cells that probably produce the peritrophic membrane; (iii) regenerative cells occurring in the ventriculus, caeca, colon, and intercolon; (iv) spherite cells and (v) digestive cells forming the ventriculus and caeca; (vi) colonic cells and (vii) intercolonic cells; and (viii) cells forming the walls of postcolonic diverticula and postcolon. Spherite and digestive cells change in structure during secretory cycles, which are described and discussed. The cycle of spherite, colonic, and intercolonic cells is terminated by apoptosis. Ingested food is packed into a food bolus surrounded by a single homogeneous peritrophic membrane formed by addition of lamellae that subsequently fuse together. The postcolonic diverticula serve as a shelter for filamentous bacteria, which also are abundant in the intercolon.     

Phenotypic flexibility of digestive system in Atlantic cod (Gadus morhua)

This study examined the restoration of the digestive capacity of Atlantic cod (Gadus morhua Linnaeus) following a long period of food deprivation. Fifty cod (48 cm, 1 kg) were food-deprived for 68 days and then fed in excess with capelin (Mallotus villosus Müller) on alternate days. Ten fish were sampled after 0, 2, 6, 14 and 28 days and the mass of the pyloric caeca, intestine and carcass determined. Two metabolic enzymes (cytochrome c oxidase and citrate synthase) were assayed in white muscle, pyloric caeca and intestine, and trypsin activity was measured in the pyloric caeca. A delay of 14 days was required before body mass started to increase markedly, whereas most of the increase in mass of both the pyloric caeca and intestine relative to fish length occurred earlier in the experiment. By day 14, the activities of trypsin and citrate synthase in the pyloric caeca as well as citrate synthase in the intestine had reached maxima. The growth of the digestive tissues and restoration of their metabolic capacities thus occur early upon refeeding and are likely required for recovery growth to take place. The phenotypic flexibility of the cod digestive system is therefore remarkable: increases in trypsin activity and size of pyloric caeca resulted in a combined 29-fold increase in digestive capacity of the fish during the refeeding period. Our study suggests that Atlantic cod are able to cope with marked fluctuations in food availability in their environment by making a rapid adjustment of their digestive capacity as soon as food availability increases.     

Description of two new species of Santelmoa (Teleostei, Zoarcidae) from the Southern Ocean

Detailed examination of eelpouts in collected material from the Gerlache Strait and the Bellingshausen Sea, during the Spanish Antarctic Expeditions Bentart 03 and Bentart 06, and from the Bransfield Strait, during the Danish Galathea 3 Expedition, at depths between 1,056 and 1,837?m, revealed two undescribed species of Santelmoa Matallanas 2010. Herein, Santelmoa fusca sp. nov. and Santelmoa antarctica sp. nov. are described on the basis of twelve specimens. Santelmoa fusca can be separated from all other Santelmoa species by the following characters: mouth terminal; two posterior nasal pores; lateral line double; two irregular rows of palatine teeth; dorsal fin rays 109–113; anal fin rays 88–94; vertebrae 27–29?+?87–91?=?114–118; two pyloric caeca well developed; scales reduced to tail; pelvic fins and vomerine teeth present. Santelmoa antarctica can be separated from all other Santelmoa species by the following characters: mouth subterminal; two posterior nasal pores; suborbital pores seven (6?+?1); lateral line double; single row of palatine teeth; supraoccipital dividing the posterior end of frontals; central radials notched; dorsal fin rays 109–112; anal fin rays 89–93; vertebrae 27?+?89–92?=?116–119; two pyloric caeca well developed; scales, ventral fins and vomerine teeth present. Santelmoa fusca and S. antarctica can readily be separated from each other by squamation (reduced to tail vs. on the tail and on the posterior part of body); suborbital pore pattern (6?+?0 vs. 6?+?1), as well as several morphometric characters. The relationships of the two new species with congeners are discussed.     

Helobdella nilae sp. nov. (Hirudinoidea: Glossiphoniidae), from the Nile Delta,Egypt

A new freshwater leech species, Helobdella nilae, is described with diagnostically a dorsal nuchal gland (scute) on somite VII, five pairs of simple crop caeca, the last pair extending posteriorly as postcaeca, five pairs of compact spherical testisacs, an unpigmented dorsal surface lacking both papillae and sensilla. The mouth is subapical and surrounded by numerous single or paired pits (pores).     

Description of two new genera, Santelmoa and Bentartia and two new species of Zoarcidae (Teleostei, Perciformes) from the Southern Ocean

Two new genera of lycodine zoarcid fish, Santelmoa and Bentartia, and two new species, Santelmoa carmenae and Bentartia cinerea, are described from 13 specimens collected from the Gerlache Strait, Southern Ocean, at 1,056-m depth. Santelmoa can be distinguished from all other lycodine genera by the combination of the following characters: anterior portion of frontals fused; scapular foramen open; ceratohyal–epihyal articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; parasphenoid wing well developed; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. Bentartia differs from the remaining lycodine genera by the following combination of characters: basioccipital and exoccipitals fused; supraoccipital–exoccipital articulation broadly contacting; ceratohyal–epihyal articulation interdigitating; post-temporal ventral ramus weak; two posterior nasal pores; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar set posteriorly; palatal arch well developed; posterior hyomandibular ramus not elongate; parasphenoid wing high; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. The relationships of the two new genera are discussed.