Printability and properties of 3D-printed poplar fiber/polylactic acid biocomposite

To efficiently and economically utilize a wood-plastic biocomposite, an eco-friendly biocomposite was prepared using modified poplar fiber and polylactic acid (PLA) via 3D printing technology for the first time. First, the effects of poplar fiber (0, 1, 3, 5, 7, and 9%) on the mechanical and rheological properties of the printed biocomposites were investigated. Subsequently, the printing parameters, including printing temperature, speed, and layer thickness, were optimized to obtain the biocomposite with superior properties. Finally, four printing orientations were applied to the biocomposite based on the optimized printing parameters to study the effect of filament orientation on the properties of the biocomposite. Favorable printability and mechanical properties of the biocomposite were obtained at 5% poplar fiber. The optimal printing temperature of 220 °C, speed of 40 mm/s, and layer thickness of 0.2 mm were obtained to produce the desired mechanical properties of the biocomposite with the printing orientation in a longitudinal stripe. However, the printing parameters should be chosen according to the applications, where different physical and mechanical properties are needed to achieve efficient and economical utilization of the biocomposites.

A new Hyphessobrycon (Characiformes: Characidae) of the Hyphessobrycon heterorhabdus species-group from the lower Amazon basin, Brazil

ABSTRACT A new species of Hyphessobrycon belonging to the Hyphessobrycon heterorhabdus species-group from the lower rio Tapajós, state of Pará, Brazil, is described. The new species is allocated into the Hyphessobrycon heterorhabdus species-group due to its color pattern, composed by an anteriorly well-defined, horizontally elongated humeral blotch that becomes diffuse and blurred posteriorly, where it overlaps with a conspicuous midlateral dark stripe that becomes blurred towards the caudal peduncle and the presence, in living specimens, of a tricolored longitudinal pattern composed by a dorsal red or reddish longitudinal stripe, a middle iridescent, golden or silvery longitudinal stripe, and a more ventrally-lying longitudinal dark pattern composed by the humeral blotch and dark midlateral stripe. It can be distinguished from all other species of the group by possessing humeral blotch with a straight or slightly rounded ventral profile, lacking a ventral expansion present in all other species of the group. The new species is also distinguished from Hyphessobrycon heterorhabdus by a 9.6% genetic distance in the cytochrome c oxidase I gene. The little morphological distinction of the new species when compared with its most similar congener, H. heterorhabdus, indicates that the new species is one of the first truly cryptic fish species described from the Amazon basin.

A new Hyphessobrycon (Characiformes: Characidae) of the Hyphessobrycon heterorhabdus species-group from the Central Amazon basin, Brazil

A new species of Hyphessobrycon Durbin from the Paraná do Urariá system in Central Amazon region, Amazonas state, Brazil, is described. The new species is allocated into the Hyphessobrycon heterorhabdus species-group due to its color pattern, composed by a well-defined, horizontally elongated humeral blotch continuous with a conspicuous midlateral dark stripe that becomes blurred towards the caudal peduncle, and can be distinguished from all other species of the group by possessing humeral blotch and continuous midlateral stripe broad, occupying vertical height equivalent of two scale rows. A tricolored pattern composed dorsally by a red or reddish longitudinal stripe, a middle iridescent, golden or silvery longitudinal stripe, and ventrally by a variably-developed longitudinal dark stripe is identified as a putative additional character shared by the species of the Hyphessobrycon heterorhabdus species-group. The presence of bony hooks in all fins in mature males of some species of the Hyphessobrycon heterorhabdus species-group is also discussed.

A new species of Hemiodus Müller (Characiformes: Hemiodontidae) from the lower Rio Xingu, Brazil

A new species of Hemiodus is described from the Rio Xingu basin, Pará, Brazil. It is distinguished from congeners by the combination of presence of a dark longitudinal stripe extending from head to tip of lower caudal-fin lobe, an oblique blotch on dorsal-fin, 9–11 scale rows above lateral line, 58–66 perforated lateral line scales, and 17–20 circumpeduncular scales. Comments on the conservation status of the new species, as well as its relationships among Hemiodus species, are made.

Redescription of Moenkhausia melogramma (Characiformes: Characidae), a poorly known tetra from the western Amazon basin

ABSTRACT Moenkhausia melogramma is herein redescribed, based on the examination of the holotype plus additional specimens from the western Amazon basin in Brazil, Colombia, Peru, and Ecuador. Moenkhausia melogramma shares with M. collettii, M. conspicua, M. copei, M. venerei, and M. flava a broad dark longitudinal stripe across the eye, and a well-defined dark stripe on the anal-fin base. It can be promptly distinguished from these species by having two humeral blotches. Additionally, we provide comments on the putative relationships of Moenkhausia melogramma with the aforementioned congeners and the Hemigrammus lunatus species-group.

Taxonomic revision of the genus Anostomoides (Characiformes: Anostomidae)

A taxonomic revision of Anostomoides is herein presented based on a comprehensive revision of specimens deposited in fish collections and the literature. The present revision proposes that A. laticeps is a junior synonym of A. atrianalis, while A. passionis is a junior synonym of Leporinus nattereri, and the latter is thus transferred to Anostomoides, forming the new combination Anostomoides nattereri. Principal Components Analysis (PCA) showed that examined specimens form two distinct morphotypes, corroborating the validity of both A. atrianalis and A. nattereri. Anostomoides nattereri is distinguished from A. atrianalis by having four branchiostegal rays (vs. three), three pores in infraorbital one (vs. four), 37–39 pored lateral-line scales (vs. 41–44), lower lip with rounded dermal papillae (vs. forming ridges), three dark rounded midlateral blotches (vs. three or four vertically elongated blotches and/or a faded dark longitudinal stripe), dark lines between scale series on posterior half of body on specimens smaller than 150 mm SL (vs. dark lines absent), a greater body depth (27.6–36.2 % vs. 24.5–38.7% of SL) and smaller interorbital distance (34.4–53.8 % vs. 42.6–67.3 % of HL). Anostomoides nattereri is distributed across several tributaries of the Amazon and Orinoco rivers, whereas A. atrianalis is widespread throughout the Amazon, Orinoco, and Essequibo basins. The genus Anostomoides is currently diagnosed based on a combination of non-exclusive characters: upturned or slightly upturned mouth with four premaxillary teeth including symphyseal tooth bicuspid or with blunt cutting edge, remaining teeth slightly tricuspid (with medial cuspid distinctly larger); four dentary teeth, symphyseal tooth with truncate cutting edge (without cusps); second tooth with a single large cusp, and two lateral teeth with three or slightly more small cusps.

New species of Eupalaestrus from Argentina (Araneae, Theraphosidae, Theraphosinae)

A new species of Eupalaestrus Pocock, 1901 from northern Argentina is described and illustrated. Males and females of Eupalaestrus larae sp. nov. differ from those all other species of the genus by the color with distinct two parallel longitudinal stripes on the femora, patellae, tibiae and one longitudinal stripe reaching half of metatarsi; the presence of a thickened femur and tibia IV; a straight embolus of the male palpal bulb and retrolateral keel pronounced. Specimens were captured in Chaco province, inhabiting unflooded flat grasslands open areas inside forest in transitional Chaco eco-region.

Two new species of striped Pseudochromis from the Philippine Islands and Indonesia, with a redescription of P. colei (Perciformes: Pseudochromidae)

Pseudochromis ammeri sp. nov. and P. eichleri sp. nov. are described from Indonesia (Raja Ampat Islands, West Irian andHalmahera) and the Philippines (Calamianes Group, Boracay and northern Palawan), respectively. In having in combina-tion a dark longitudinal stripe on the body and the anterior tip of the palatine tooth patch directed medially behind poste-rolateral arm of vomerine tooth patch, the two species closely resemble P. colei Herre from the Philippines. The latterspecies is redescribed on the basis of the holotype from Culion and two specimens recently collected in northern Palawan. The three species closely resemble each other but differ in live coloration and several scale count characters.

Taxonomic notes, new species and identification key to the New World species of Toxophora Meigen (Diptera, Bombyliidae, Toxophorinae)

Two new species of Toxophora Meigen are described and illustrated—T. paulistana sp. nov. (Neotropical) and T. azteca sp. nov. (Nearctic and Neotropical). An identification key to the New World species is also presented. Morphological differences between populations of T. aurea Macquart (1848) are recorded, illustrated and added to the key. The new species are easily recognized by: scape with long, yellow scales laterally; presence of yellow scales on mesonotum margins; posterior margin of mesonotum with a pre-scutellar pair of setae; and yellow scales forming thin bands on posterior margins of abdominal tergites in T. paulistana sp. nov., and scape entirely covered with long dark-brown scales and yellow scales forming a broad, longitudinal stripe on center of abdominal tergites III-VII in T. azteca sp. nov.

Two new species of Moenkhausia Eigenmann (Characiformes: Characidae) from Serra do Cachimbo, Pará, Northern Brazil

Two new species of Moenkhausia, one from the rio Tapajós and the other from the rio Xingu basins are described as apparently endemics of the Serra do Cachimbo. Both species, along with M. petymbuaba, share a distinct color pattern composed of large conspicuous dark blotches on the base of the body scales. Moenkhausia chlorophthalma, from rio Treze de Maio, a tributary to rio Curuá (rio Xingu basin), is distinguished by the presence of a proximal well delimited black area on the adipose fin and a green eye in life. Moenkhausia plumbea of the headwaters of tributaries of the rio Braço Norte, rio Tapajós basin is diagnosed by the presence of a dark longitudinal stripe across the eye and six branched pelvic-fin rays (vs. seven). Relationships of the new species with other Moenkhausia are discussed.