Description of a new species of giant guitarfish, Glaucostegus younholeei sp. nov. (Rhinopristiformes: Glaucostegidae) from the northern Bay of Bengal, Bangladesh

A new species of giant guitarfish, Glaucostegus younholeei sp. nov., is described from 13 specimens, 730–933 mm total length, collected from fish landing center of Bangladesh Fisheries Development Corporation in Cox’s Bazar district of Bangladesh. The new species is distinguished from congeners in having the following combination of characters: Body brownish or greyish in color with a narrowly wedge-shaped disc, and long narrow bluntly pointed snout (angle 31–40°), and broad oblique nostrils with the narrow anterior opening. Nostrils about half of the mouth width, subequal (0.98–1.33) to internasal width; ~55–57 nasal lamellae; anterior nasal flaps slightly penetrating into internasal space, their interspace 2.20– 2.61 in length of the posterior nasal aperture. Orbit very small in adults, diameter 8.19–11.62 in preorbital length, 2.25–2.69 in interorbital space. Rostral ridges almost joined along their entire length; margin of cranium sharply demarcated before eyes. Spiracular folds very short and widely separated. Skin rough, densely covered with small denticles, more coarsely granular on the dorsal surface than ventrally, enlarged between orbits and in a distinct band between nape and first dorsal fin. Tail relatively longer, length 1.15–1.48 in disc length; dorsal fins narrowly spaced, interspace 1.32–2.11 in base length of the first dorsal fin. Clasper length in adult male 4.37–5.70 in total length. Phylogenetic analysis of DNA barcode sequences also shows the clear divergence of Glaucostegus younholeei from other congeneric species obtained from GenBank. A key is provided to the 8 known members including new species of the genus Glaucostegus.

Proper positioning of mice for Cobb angle radiographic measurements

Background There is no recommended standard for positioning of a mouse for radiographic assessment of the spine. This is necessary to have reproducible radiographic data and avoid false positive results. The objective of this study was to investigate the impact of various postures on Cobb angle measurements and to set up a positioning standard for imaging mouse spines. Methods This study was conducted in three parts. Firstly, we identified the problem of lack of posture standardization for radiographs. We collected 77 C57BL/6 J mice for spine radiographs and found a scoliosis prevalence of 28.6% with large variations in curve magnitude. Secondly, 24 C57BL/6 J mice underwent 4 consecutive weekly radiographs and observed high variations (relative standard deviation: 125.3%) between radiographs. Thirdly, we collected another 82 C57BL/6 J mice and designed 14 different postures that could take place during imaging. These postures were related to curling of the limbs, and head, pelvic and tail tilting. Results The results showed that head and pelvic tilting significantly affects the curve magnitude with effect size (Glass’s delta) over 1.50. Avoiding these incorrect positions during radiographs is warranted. The standard recommended posture for mouse imaging entails positioning the snout, interorbital space, neck and whole spine in one line, and with the limbs placed symmetrical to the trunk, whilst avoiding stretching the body of the mouse. Conclusions Our work exemplified the importance of standard protocol during imaging when using an animal model in the scoliosis study. We recommend utilizing this standard in studying various disorders of the spine to avoid technical causes for the appearance of a curve.

Proper positioning of mice for Cobb angle radiographic measurements

BackgroundThere is no recommended standard for positioning of a mouse for radiographic assessment of the spine. This is necessary to have reproducible radiographic data and avoid false positive results. The objective of this study was to investigate the impact of various postures on Cobb angle measurements and to set up a positioning standard for imaging mouse spines. MethodsThis study was conducted in three parts. Firstly, we identified the problem of lack of posture standardization for radiographs. We collected 77 C57BL/6J mice for spine radiographs and found a scoliosis prevalence of 28.6% with large variations in curve magnitude. Secondly, 24 C57BL/6J mice underwent 4 consecutive weekly radiographs and observed high variations (relative standard deviation: 125.3%) between radiographs. Thirdly, we collected another 82 C57BL/6J mice and designed 14 different postures that could take place during imaging. These postures were related to curling of the limbs, and head, pelvic and tail tilting. ResultsThe results showed that head and pelvic tilting significantly affects the curve magnitude with effect size (Glass’s delta) over 1.50. Avoiding these incorrect positions during radiographs is warranted. The standard recommended posture for mouse imaging entails positioning the snout, interorbital space, neck and whole spine in one line, and with the limbs placed symmetrical to the trunk, whilst avoiding stretching the body of the mouse. ConclusionsOur work exemplified the importance of standard protocol during imaging when using animal model in the scoliosis study. We recommend utilizing this standard in studying various disorders of the spine.

Sexual dimorphism in Scutiger boulengeri, an endemic toad from the Tibetan Plateau

The evolution of sexual dimorphism has long fascinated evolutionary biologists and theory suggests that variation in sexual dimorphism is a consequence of selective forces acting differently on morphological traits in males versus females. Here, we analyzed sexual differences in size and shape of the Boulenger’s lazy toad, Scutiger boulengeri, based on the intersex variation pattern of sixteen morphometric traits including body size. The results suggested that sexual dimorphism was apparent in body size and some body shapes (e.g., head length and width, internasal space, interorbital space, diameter of lower arm and tibia width) of this toad. The bigger body size in females may be relevant to fecundity selection, a larger head in males as well as a broader internasal and interorbital space may be subject to male-male competition in combination with ecological selection, and both robust forelimbs and hindlimbs in males may be related to mating and competitive behaviors. These results are discussed with respect to the above selection procedures and possible sex differences in life history traits.

The method of trophy assessment of capercaillies

The capercaillie as one of the most important hunting objects in Russia has not yet been included in the list of esti-mated hunting trophies due to the lack of an acceptable assessment methodology. The aim of the work is to develop a method for assessing the trophy advantages of a capercaillie. The objects of the study were morphological indicators which expressed the size and the age of the birds caught. The study involved 39 stuffed animals of capercaillie, 47 carcasses of freshly caught birds and 105 skulls from research collections. Measurement of taxidermy products (stuffed animals and museum carcasses) gives inaccurate information about the fowl caught. It is preferable to use the skull of a male capercaillie as a trophy. In the system of the International Council for the Hunting and Preservation of the Wildlife (CIC) the traditional measurements of the skull are the maximum length and width. In trophy animals, the scull size sufficiently reflects the sum of these indicators, therefore they are chosen for trophy assessment. For capercaillie, the correlation of similar pro-meters with body weight was not so close r = 0.489. In authors’ opinion, the assessment method should include the size of the interorbital space as an addi-tional parameter. This measurement is used in methods for determining the age of capercaillies caught. The formula for scoring is the product of the interorbital space by the sum of the maximum length and width of the skull. The correlation coeffi-cient between the trophy rating by this formula and the bird weight in this study is rm = 0.931, and the trophy rating and age rv = 0.920. The intervals of the final points for awarding the medals are: bronze  55-59.99 points, silver  60-64.99, gold  more than 65 points. This assessment system was successfully tested at two exhibitions of hunting trophies held in the Kirov region in 2017, and was approved by expert commissions.

Description of New Illinois Fishes

A sunfish of the Xenotis of average proportions, rather thin in front, the dorsal outline before the fin well arched, with a decided depression at the nape. Length 4 inches, depth 2.25 ill length. Color dark, with a purplish tint; sides striped with rows of bronze blotches, one to each scale, about seven rows below the lateral line. Sides of the head in alcoholic specimens with an appearance of irregular lines. Opercular flap large, about two-thirds the length of the eye. bordered above and below, but not posteriorly with pale. Head 2.75 to 2.9 in length: nose 3.9 to 4.25: interorbital space slightly greater than length of eye.—3.4 to 3.75 in head. Mouth normal, moderate; rudimentary maxillary bone minute; upper jaw below the middle of the pupil; maxillary 2.85 to 3.1 in head, scarcely reaching the front of the pupil; lower jaw 2 to 2.4; teeth on vomer, not on palatines.

A new species of the Amolops monticola group (Anura: Ranidae) from southwestern Yunnan, China

We describe the new species Amolops mengdingensis sp. nov. from southwestern Yunnan, China. It belongs to the Amolops monticola species group and phylogenetically clusters together with Amolops akhaorum and Amolops archotaphus with strong support, although the relationships between these three species are not resolved. Distance between the new species and A. akhaorum is 4.7% and distance between the new species and A. archotaphus is 5.2% for 16S rRNA sequences. The new species is characterized by the following characters: distinct dorsolateral folds; side of the head dark brown with a white upper lip stripe extending to the axilla; dorsal surface smooth, except white spinules on posterior part of dorsolateral folds and above vent; top of head and dorsum green with dark spots in life; loreal region dark brown and flanks brown without any coloration of green; SVL 36.9–40.2 mm in males and 64.3 mm in female; two external subgular vocal sacs in males; vomerine teeth in two oblique ridges, separated by a small distance; pineal body absent; snout longer than eye diameter; internarial space broader than interorbital space; tympanum distinct, smaller than half of eye diameter; all fingertips expanded; two palmar tubercles; outer metatarsal tubercle absent; tibiotarsal articulation reaching beyond snout tip; near immaculate venter; limbs dorsally grayish brown with clear dark brown bars on hindlimbs; and velvety nuptial pads.

Extension in distribution of Raorchestes parvulus (Boulenger, 1893) (Anura: Rhacophoridae) to China

We record Raorchestes parvulus (Boulenger, 1893) for the first time from China based on six specimens collected from southern Yunnan. Phylogenetically these individuals were placed in a clade with R. parvulus from Southeast Asia and pairwise genetic distances in DNA sequences of the mitochondrial 16S rRNA gene ranged from 0 to 3.1% within the clade. Morphologically these specimens agree with R. parvulus in a series of characters including body size small, a large external vocal sac, vomerine teeth absent, snout slightly shorter than the diameter of the orbit, canthus rostralis indistinct, interorbital space broader than the upper eyelid, tympanum indistinct, fingers free, toes webbed at the base, an inner metatarsal tubercle, tibio-tarsal articulation reaches eye, small warts on the dorsal surfaces of body and limbs, throat smooth, belly granular, a dark triangular blotch between the eyes, a butterfly-like dark band on the back, a dark blotch on each side of lumbar region, and more or less distinct dark bars across limbs. Obvious intraspecific variation in the color pattern occurs within the population. It is possible that previous records of Raorchestes longchuanensis (Yang and Li, 1979) from southern Yunnan might be misidentification of R. parvulus.

Squalus clarkae sp. nov., a new dogfish shark from the Northwest Atlantic and Gulf of Mexico, with comments on the Squalus mitsukurii species complex

Sharks of the genus Squalus have slow reproductive rates coupled with low genetic diversity, as is typical of deep-water sharks, making this group slow to rebound from depletion due to overfishing. The number of species within Squalus has been expanding recently due to increased attention on taxonomic revision, and a growing research focus on little-known deep-water sharks in general. Here we use genetics and morphology to describe a new species of dogfish shark, Squalus clarkae sp. nov. from the Gulf of Mexico (GoM) which replaces Squalus mitsukurii in this region, and place it in the context of congeners from the Atlantic and elsewhere. Previously, S. clarkae sp. nov. was considered a part of the Squalus mitsukurii species complex, a group of closely related but distinct species. We sequenced the mitochondrial cytochrome oxidase I and the NADH Dehydrogenase II gene of S. mitsukurii from the type location in Japan, S. clarkae sp. nov. from the GoM, as well as three closely related species (S. cubensis, S. blainville, and S. megalops) and S. cf. mitsukurii from Brazil. Squalus clarkae sp. nov. is genetically distinct from other species with significant statistical support (>98.6% bootstrap support/posterior probability), and 2.8% divergent from S. mitsukurii in the type location of Japan. Morphological estimates also revealed differences between S. clarkae sp. nov., S. mitsukurii, and other Atlantic Squalus species, with S. clarkae sp. nov. exhibiting a longer body, smaller interorbital space, shorter caudal fin, and a differently-proportioned first dorsal fin. In general, dogfish sharks in the Atlantic and GoM are characterized by similar but distinct morphology, significant genetic variation, and small species ranges.