Rostrum Width Research Articles

Sex difference, growth pattern, and cephalic index of Turi ducks at different ages based on head morphometry

This study aims to determine the morphometric differences in the head of male and female Turi ducks. Ten male and ten female day-old ducks (DOD) were randomly selected by a lottery system from the population, raised, and had their head morphology measured using a digital caliper with an accuracy of 0.01 mm on the first day, and at the age of 2, 4, 6, and 8weeks. The result showed that male Turi duck had wider (p <0.05) head at the ages of 1 day, 2 and 6 weeks, head length and head height at the ages of 1 day, 2, 4, 6, and 8 weeks, rostrum width at the ages of 1 day, 4, 6, and 8 weeks, and rostrum length at the age of 2, 4, 6 and 8 weeks. There were no significant differences (p >0.05) in the head width at the ages of 4 and 8 weeks, rostrum width at 2 weeks, and rostrum length at 1day old male and female Turi ducks. Morphometric growth pattern showed that older Turi ducks (at a range of 1 day to 8 weeks) had larger (p <0.05) head morphometry. However, the cephalic index in male and female Turi ducks was not significantly different (p > 0.05) at all ages. It could be concluded that in general head morphometry was useful for determining male and female Turi ducks at the ages of 1 day, 2, 4, 6, and 8 weeks

Factors affecting the location of sphenoid sinus ostium: a binary logistic regression analysis.

Sphenoid sinus is a type of sinus surrounded by critical structures so that its injury potential to induce complications during surgery. The purpose of this study was to investigate the factors affecting the location of the sphenoid sinus natural ostium (SSO) to provide valuable data for endoscopic sinus surgery. Ostiomeatal unit (OMU) computerized tomography (CT) was performed on 198 subjects. Across the left and right sides, 396 evaluation results were obtained. The vertical distance to determine the location of the SSO was analyzed based on Lines 1, 2 and 3 on the sagittal image. The horizontal distance was analyzed based on Lines 4 and 5 on the axial image. The upper, lower, medial and non-medial borders were defined according to the location of the SSO. The presellar, sellar and postsellar types were categorized according to the level of sphenoid sinus pneumatization (SSP) on the sagittal image. The presence and absence of Onodi cells were defined on the coronal image. Binary logistic regression analysis was performed to investigate each factor. As the rostrum width of the SSO on the horizontal position increased, the position toward non-medial boarder increased by 4.902 times so that the natural ostium showed a trend of lateralization. For the postsellar type, compared to the presellar type, the position toward the non-medial boarder decreased by 0.223 times, indicating that the postsellar type had the natural ostium showing a trend of medialization. In the presence of Onodi cells, the position toward the lower boarder increased by 2.599 times with a significant association. The results in this study indicated that the presellar type of SSP had the natural ostium exhibiting lateralization with an increase in the rostrum width, whereas the postsellar type had the natural ostium exhibiting medialization with a decrease in the rostrum width. Based on these findings, the methods to widen the natural ostium may be diversified.

Morphometric characteristics and condition indices of stone crayfish Austropotamobius torrentium (Shrank, 1803) from the Mlinska River

Regarded as a protected species on the IUCN list of endangered species, and classified as data deficient species, the stone crayfish (Austropotamobius torrentium) is one of the five European species from the Astacidae family that lives in freshwater ecosystems across Bosnia and Herzegovina. The aim of this study was to investigate the variability of selected morphometric characteristics of male and female crayfish of the A. torrentium species from the upper reaches of the Mlinska River. The crayfish were sampled in June 2021 when 62 individuals (22 males and 40 females) were caught. They were analyzed fresh in the field and in the laboratory. The treatment included the measurement of 12 morphometric features: total body length (TBL), weight (W), claw length (CLL), claw width (CLW), carapace length (CPL), carapace width (CPW), rostrum length (ROL), rostrum width (ROW), abdominal length and width (ABL, ABW) and telson length and width (TEL, TEW). The mean body length ± SD was 79.05 ± 7.35 in males and 60.54 ± 10.03 mm in females. The mean recorded body weight ± SD was 17.51 ± 8.3 g in males and 7.02 ± 4.41 g in females. Using the linear regression method, a positive correlation was found between body length and weight (♂ R2=0.7644; ♀ R2=0.8222), body weight and claws length (♂ R2=0.876; ♀ R2=0.9661), as well as carapace width and body length (♂ R2=0.7216; ♀ R2=0.8411). Using the T-test, a statistically significant difference of the analyzed morphometric parameters was found between the sexes, which is explained by the pronounced sexual dimorphism of stone crayfish. The calculated values for Condition factor and the Crayfish constant indicate that the males are of better fitness, which is in line with the results of previous research in Europe. Data presented in this paper can serve as a basis for further research of A. torrentium in this area.

O vorvaních (Physeter macrocephalus) ve sbírce Národního muzea v Praze (Mammalia: Artiodactyla)

A complete skeleton of the sperm whale (Physeter macrocephalus) from an animal ca. 13–14 m long is here reported as a new acquisition to the collection of mammals of the National Museum in Prague. This large new specimen was transferred to Prague museum from the Zoological museum of Senckenberg Natural History Collection Dresden, Germany, where a space enough was not available in the collection depositary rooms for its storage (the skull was stored outdoors, the rest of the skeleton in a taxidermy workshop). The skeleton originates from a stranded individual of the sperm whale discovered (along with two others) on the North Sea shore at Friedrichskoog (Holstein, Germany) on 15 January 2002. Selected measurements of the skull of this sperm whale are as follows: condylobasal length of skull 418 cm, orbital width of skull 196 cm, basal width of rostrum 144 cm, length of left mandible 374 cm, mandible height at the ramus mandibulae 58 cm. An annotated review of museum specimens of the great whales (= baleen whales and the sperm whale) in collections in the Czech Republic and a detailed description of the sperm whale specimens in the National Museum are added.

Morphology and Morphometry of Foetal Corpus Callosum Using MRI – A Retrospective Study

Introduction: Corpus callosum (CC) is the largest commissural white fibres interconnecting cerebral hemispheres. The corpus callosum is responsible for interhemispheric transfer of information which is essential for cognitive function. The foetal corpus callosum serves as sensitive indicator for normal brain development and maturation. As the corpus callosum is a part of the highest order latest maturing mental network of the brain, its measurements are important to assess normal brain development and to locate structural changes. A comprehensive evaluation of normal human foetal corpus callosal development is essential to detect and understand the congenital anomalies of the brain. Thus, the prenatal diagnosis of partial or complete agenesis of the corpus callosum is important for predicting the normal development of the foetus. Foetal neural anomalies that are suspected on prenatal ultrasonography (USG) can be detected in early stage using foetal MRI. This imaging technique is highly useful for detailed visualization of normal neural development. Certain conditions like colpocephaly and widening of interhemispheric fissure can be clearly visualized using foetal MRI when compared to prenatal ultrasonography. Aim and objective: Was to establish the normal reference values for the measurement of foetal corpus callosum. The length and thickness of the foetal CC was measured corresponding to gestational age (GA) between 18-36weeks. Materials and methods: A retrospective MRI study was carried out in Radiology department of Sri Ramachandra Hospital. The study was conducted on 50 pregnant women with GA of 18-32 weeks and morphology of foetal corpus callosum was measured using MRI. The corpus callosum was visualized in a mid-sagittal plane as an anechoic structure, delimited by two echogenic lines superiorly by sulcus of the corpus callosum and inferiorly by the septum pellucidum. The length of corpus callosum was measured from the anterior most aspect of genu to the posterior most aspect of the splenium and the width of individual parts were measured and correlated with gestational age. The values obtained from the study were statistically calculated using regression coefficient method. Results: In the present study following parameters were observed such as length and width of diverse parts of Corpus callosum. The length of foetal CC ranged from 25.96 to 47.2 mm in 18 to 32 weeks of gestational age. The range of width of rostrum, genu, body and splenium were 1.2 to 2.2 mm, 1.2-2.8mm, 1.3-3.1mm and 1.36-3.2mm respectively. Conclusion: The periodic development of nervous system can be calculated more effectively with the morphometric measurement of foetal CC and its correlation with BPD. It is considered to be accurate than using BPD measurement of head circumference in USG. Hence, with the normative data of foetal CC measurements correlated with gestational age would give us accurate details of neuronal growth rather than measuring biparietal diameter (BPD) alone using USG. This knowledge will be highly helpful for the gynaecologists to predict the abnormal development of the foetus and it is advised to include foetal CC parameters as a one of the tools for early detection of CNS anomalies.

MORPHOLOGICAL VARIABILITY AND SEXUAL DIMORPHISM OF NOBLE CRAYFISH Astacus astacus FROM THE BALKANA LAKE

This paper presents the information about morphological variability and sex dimorphism of the Noble crayfish (Astacus astacus) in the area of the Balkana Lake in Mrkonjic Grad. The crayfish were caught by hand made baited traps from October 9nd 2018. until May 31th 2019. A total of 58 crayfish were caught, of which 38 males and 20 females. The eight morphometric characteristics: body weight (W), body length (TBL), claw length (CLL), cephalothorax length (CFL), carapace width (CPW), abdomen length (ABL), rostrum length (ROL) and rostrum width (ROW) were measured, both in males and females. Also, the body condition was determined for all specimens. The results of morphometric characteristics partially matched into the already known range of variations. These data represent first ones for the observed area. The t-test showed that there were significant differences between the sexes in W, TBL, CLL, CFL and CPW which are explained by the emphasized sex dimorphism of the noble crayfish.

Investigations of Variability of Morphometric Characteristics in Stone Crayfish in Order to Preserve Autochthonous Genome

This paper presents the information about morphological variability and sexual dimorphism of the stone crayfish (Austropotamobius torrentium) in the area of Korana River in Mrkonjic Grad. The crayfish were caught by hand made baited traps from October 2018 to May 2019. A total of 46 crayfish were caught, of which 33 males and 13 females. The dimensions of eight morphometric characteristics: body weight (W), body length (TBL), rostrum length (ROL), rostrum width (ROW), claw length (CLL), carapace length (CPL), carapace width (CPW) and abdomen length (ABL), were analyzed, both in males and females. Also, the body condition was determined for all individuales. The measurements results of morphometric characteristics partially matched into the alredy known range of variations. These data presens first ones for the observed area. By using Mann-Whitey U-test, it was noted that there are significant differences between the sexes for W, TBL, CLL, CPL, CPW and ABL. These resuls could be explained by sexual dimorphism of the stone crayfish.

Morphological variability and sexual dimorphism of noble crayfish Astacus astacus from the Balkana Lake

This paper presents the information about morphological variability and sex dimorphism of the Noble crayfish (Astacus astacus) in the area of the Balkana Lake in Mrkonjic Grad. The crayfish were caught by hand made baited traps from October 9nd 2018. until May 31th 2019. A total of 58 crayfish were caught, of which 38 males and 20 females. The eight morphometric characteristics: body weight (W), body length (TBL), claw length (CLL), cephalothorax length (CFL), carapace width (CPW), abdomen length (ABL), rostrum length (ROL) and rostrum width (ROW) were measured, both in males and females. Also, the body condition was determined for all specimens. The results of morphometric characteristics partially matched into the already known range of variations. These data represent first ones for the observed area. The t-test showed that there were significant differences between the sexes in W, TBL, CLL, CFL and CPW which are explained by the emphasized sex dimorphism of the noble crayfish.

A new species of Proterhinus Sharp, 1878 (Coleoptera: Curculionoidea: Belidae)from Miti'aro, Cook Islands, South Pacific.

Proterhinus tauai Brown, new species is described from specimens collected on the island of Miti'aro in the Cook Islands, South Pacific. It differs from congeners by the combination of having a dorsal vestiture of decumbent brown clavate scales, lacking erect elongate setae, anterior pronotal angles projecting forwards, and having short antennae that do not reach the posterior margin of the pronotum. This species shows strong sexual dimorphism in the shape of the rostrum, with males having a large semicircular rostrum, compared with a stout subrectangular rostrum in females. Fitting allometric models to the relationship of morphometric variables with body length show that rostrum width and area have significantly different allometric relationships between the sexes, consistent with hypotheses of sexual selection. Proterhinus tauai was collected from coastal scrub vegetation. Collection data and observation of captive specimens indicate a host relationship with the parasitic vine Cassytha filiformis L. (Lauraceae).

Using Different Standardized Methods for Species Identification: A Case Study Using Beaks from Three Ommastrephid Species

The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method for identifying different species by measuring 12 morphological variables of the beaks of Illex argentinus, Ommastrephes bartramii, and Dosidicus gigas that were collected by Chinese jigging vessels. To remove the effects of size, these morphometric variables were standardized using three methods. The average ratios of the upper beak morphological variables and upper crest length of O. bartramii and D. gigas were found to be greater than those of I. argentinus. However, for lower beaks, only the average of LRL (lower rostrum length)/LCL (lower crest length), LRW (lower rostrum width)/LCL, and LLWL (lower lateral wall length)/LCL of O. bartramii and D. gigas were greater than those of I. argentinus. The ratios of beak morphological variables and crest length were found to be all significantly different among the three species (P < 0.001). Among the three standardization methods, the correct classification rate of stepwise discriminant analysis (SDA) was the highest using the ratios of beak morphological variables and crest length. Compared with hood length, the correct classification rate was slightly higher when using beak variables standardized by crest length using an allometric model. The correct classification rate of the lower beak was also found to be greater than that of the upper beak. This study indicates that the ratios of beak morphological variables to crest length could be used for interspecies and intraspecies identification. Meanwhile, the lower beak variables were found to be more effective than upper beak variables in classifying beaks found in the stomachs of predators.

Morphometric variations among Astacus astacus populations from different regions of the Balkan Peninsula

The morphometric variation among several populations of Astacus astacus from different regions of the Balkan Peninsula was studied based on a large set of morphometric parameters per crayfish. Differences in morphometry among populations from ten water bodies in Serbia, Slovenia and Albania were tested using a multiple discriminant analysis. Analyses included twenty-two morphometric parameters per crayfish. The most discriminant characteristics for separating males among populations were weight, head width (HEW), width of the carapace at the hind edges (CEW) and claw length (CLL), and for female populations those were abdomen length (ABL), rostrum width (ROW), total length (TL), claw length (CLL) and claw width (CLW). Our results improve the existing knowledge about the noble crayfish morphology, show clear differentiation between populations from various aquatic ecosystems and reflect geographical separation.

Cambarus (P) theepiensis, a new species of crayfish (Decapoda:Cambaridae) from the coalfields region of Eastern Kentucky and Southwestern West Virginia, USA.

Cambarus (Puncticambarus) theepiensis is a stream-dwelling crayfish that appears to be endemic to the junction of the Cumberland Mountains with the Appalachian Plateau in West Virginia and Kentucky. Within this region, it is prevalent in the Guyandotte and Twelvepole basins of West Virginia, the Little Sandy River and Levisa Fork basins of Kentucky, and tributaries of the Big Sandy River shared by both states. The new species is morphologically most similar to Cambarus robustus and Cambarus sciotensis. It can be differentiated from C. robustus by its broad rostrum, with subparallel, thick-ened margins compared to the narrow, converging rostrum with reduced rostral margins of C. robustus.; larger areola width/length ratio (26 %) than C. robustus (22 %); and mottled color pattern compared to the monotypic color pattern of C. robustus. Canibarus theepiensis can be differentiated from C. sciotensis by the presence of a distinct lateral impression on the chelae compared to the absence of a lateral impression in C. sciotensis; constant thickness of the rostral margin compared to the gradation of rostral thickness in C. sciotensis; greater rostrum width/ length ratio in C. theepiensis (63.1 %) compared to C. sciotensis (57.2 %); and a central projection on the gonopod that is the same length as the mesial process, compared to a central projection that extends past the tip of the mesial process in C. sciotensis.

THE MORFOMETRICS CHARACTERICS AND CONDITION INDEX OF AUSTROPOTAMOBIUS PALLIPES IN THE NERETVA RIVER BASIN

UDK 595.384.1:591.134(282.249 Neretva)&#x0D; Specimens of white-clawed crayfish have been cought during from May to August 2011. The specimens were fished out from the tributaries of the river Neretva: Neretvica, Sistica and Kraljuscica. The study was done on 100 m of waterstream, where an unequal numbers of individuals was determined. 31 individuals was found in river Neretvica, 10 individuals in river Sistica and 4 in river Kraljuscica. Different hydromorphological characteristics of the waterstream have largely contributed to the different population abundance of this crayfish. Morphometric analysis included six parameters: (TL) total length [cm], (W) weight (gr), (ARL) carapace length [cm], (CPW) carapace width [cm], (ROL) rostrum length [cm], (ROW) rostrum width [cm], (CLL) claws length [cm] and (TEL) tail length [cm]. Total body length of the white- clawed crayfish varied from 4.3 to 8. 6cm, while the individual with maximum length was found in river Neretvica. Weight of the individuals varied from 5g to 26g. Weight is the parameter with the highest coefficient of variation where differences in weight were found in the individuals of equal length. According to the shape (length and width) of the rostrum, crayfish from river Neretvica and Kraljuscica had higher similarity than recripocally than with the individuals cought in river Sistica (isosceles triangle). The connection between body length and carapax width had been determined by linear regression, as well as the connection between body length and claws length. Condition index values are higher in males than in females and the male domination was express in all three watercourses, as well as in the overall sample (28males and 17 females).

阿根廷滑柔鱼两个群体间耳石和角质颚的形态差异

头足类硬组织具有稳定的形态特征、良好的信息储存以及抗腐蚀性等特点。根据2007年2-5月和2010年1-3月我国鱿钓船采集的阿根廷滑柔鱼样品,提取出625对耳石和787对角质颚,测量耳石10个形态数据和角质颚12个形态数据,通过除以胴长(Mantle Length, ML)校正后,对南巴塔哥尼亚群体(South Patagonic Stock, SPS)和布宜诺斯艾利斯-巴塔哥尼亚群体(Bonaerensis-Northpatagonic Stock, BNS)形态差异进行分析,并建立不同群体的判别函数。结果表明,BNS群体耳石和角质颚外形参数雌性大于雄性,而SPS群体则为雄性大于雌性。均数差异性检验认为,同一群体不同性别的耳石总长(Total Statolith Length, TSL)、最大宽度(Maximum Width, MW)、侧区长(Lateral Dome Length, LDL)、翼区长(Wing Length, WL)、翼区宽(Wing Width, WW)存在显著差异(<em>P</em><0.05),同性别不同群体的MW、背侧区长(Dorsal Lateral Length, DLL)、吻侧区长(Rostrum Lateral Length, RLL)和WW存在显著差异(<em>P</em><0.05)。而同一群体不同性别间角质颚的上头盖长(Upper Hood length,UHL)、上脊突长(Upper Crest length,UCL)、上喙长(Upper Rostrum length,URL)、上喙宽(Upper rostrum width,URW)、上侧壁长(Upper Lateral wall length,ULWL)、下喙长(Lower Rostrum length, LRL)存在显著差异(<em>P</em><0.01),同一性别不同群体角质颚的下头盖长(Lower Hood length, LHL)、下脊突长(Lower crest length, LCL)、LRL、下喙宽(Lower Rostrum width,LRW)、下侧壁长(Lower Lateral wall length,LLWL)、下翼长(Lower Wing length, LWL)存在显著差异(<em>P</em><0.01)。耳石形态参数经主成分分析,认为BNS群体雌雄的主成分因子主要集中在TSL/ML、DLL/ML、RW/ML和MW/ML,SPS群体主要集中于TSL/ML、RW/ML、WW/ML和DDL/ML;角质颚形态参数经主成分分析,认为BNS群体主成分因子主要集中在UHL/ML、UCL/ML、ULWL/ML和 LRW/ML,SPS群体主要集中在UHL/ML、UCL/ML、ULWL/ML、URL/ML、LWL/ML和LRL/ML。利用角质颚和耳石对两群体样本分性别建立了判别函数,判别正确率均高于60%,所划分群体在部分形态指标上差异明显,具有一定的可信度。今后应加强样本采集个体大小和时间跨度,以更好的分析其群体变化规律。;The Argentinean short-finned squid,<em> Illex argenginus</em>, is a common neritic specie with a wide distribution from approximately 22°S to 54°S along the continental shelf and slope waters and around the Falkland/Malvinas Islands in the Southwest Atlantic Ocean. It is a cepholopod species of great commercial importance targeted by international fishing fleets consisting of both jigging fleets from Asian countries and trawelers from European countries. This species also plays a crucial role in its marine ecosystem in the southwest Atlantic Ocean. The Argentinean short-finned squid had a complicated intrapopulation structrue. At least five major intraspecific stocks are defined based on length at maturity, spawning, hatching time and distribution of animals in early life history stages. Its hard structures, including beaks and statoliths, have stable morphological characteristics, and are resistance to corrosion to a certain extent and suitable for life history information storage. They are often used separately in previous studies, and few studies have used both hard structures in studying squid life history. In this study, using specimens of Argentinean short-finned squid collected by the Chinese squid Jigging fishery fleet during February to May in 2007 and from January to March in 2010, we extracted 625 pairs of statolith from statocysts and 787 pairs of beaks from buccal masses.Ten morphological variables were measured for statoliths and 12 morphological variables were measured for beaks. These morphological variable measurements were standardized using mantle length (ML), which were then used to compare differences among the stocks (i.e., South Patagonic Stock, SPS; and Bonaerensis-Northpatagonic Stock, BNS)and between the sexes. This study showed that the morphological variables of statolith and beak for BNS females were larger than those of males. However, for the SPS cohort, male morphological variables tended to be larger than those of females. A Student's t-test showed that for a given stock the statoliths had significant differences between the sexes in the following morphological variables: Total Statolith Length (TSL), Maximum Width (MW), Lateral Dome Length (LDL), Wing Length (WL), and Wing Width (WW) (<em>P</em><0.05). For a given sex, significant differences between the two stocks were found in MW, Dorsal Lateral Length (DLL), Rostrum Lateral Length (RLL), and Wing Width (WW) <em>(P</em><0.05). Student's t- test also showed that for a given stock beaks had significant differences between the sexes in Upper Hood length (UHL), Upper Crest length (UCL), Upper Rostrum length (URL), Upper rostrum width (URW), Upper Lateral Wall Length (ULWL), Lower Rostrum length (LRL) (<em>P</em><0.01).For a given sex, significant differences were found in Lower Hood length (LHL), Lower crest length (LCL), LRL, Lower Rostrum width (LRW), Lower Lateral Wall Length (LLWL), Lower Wing Length (LWL) between the two stocks (<em>P</em><0.01). The majority of data variability in principal component analysis of statolith could be explained by TSL/ML, DLL/ML, RW/ML, MW/ML for the BNS and by TSL/ML, RW/ML, WW/ML, DDL/ML for the SPS. The majority of data variability in principal component analysis of beaks could be explained by UHL/ML, UCL/ML, ULWL/ML and LRW/ML for the BNS and by UHL/ML,UCL/ML, ULWL/ML, URL/ML, LWL/ML, LRL/ML for the SPS. When statolith and beaks were used to establish the discrimination function, accuracy rates in distinguishing the two cohorts were above 60%. These findings suggested that the cohorts of <em>Illex argentinus</em> in the Southwest Atlantic Ocean could be morphologically indentified. However, more samples and longer time series of data may be needed for further validation of this approach and evaluation of uncertainty associated with the results.

Sexual dimorphism in Trachylepis aurata transcaucasica Chernov, 1926 (Reptilia: Scincidae) in the Zagros Mountains, western Iran

Forty-nine preserved specimens (31 male and 18 female) of Trachylepis aurata transcaucsasica were examined with respect to metric and meristic features and dry skull anatomy to assess sexual dimorphism. Thirty-one morphological characters and 36 anatomical characters in dry skulls were examined. Subdigital lamellae under the forth toe, neck length, neck length/snout vent length, and six skull characters (skull length, condylobasal length, anterior rostrum width, eye width, and ratios of maxilla length to skull length and pterygoid length to skull length) were significantly different in males and females (P < 0.05). Other observed differences were in the base of the tail, which was thicker in males than in females, and in the structure of the anus. The sexes did not show dimorphism in color or pattern.

Rhynchophorus ferrugineus and Rhynchophorus palmarum

<i>Rhynchophorus ferrugineus </i>and<i> Rhynchophorus palmarum</i>

Contribution to the taxonomic status of the Chinese rats Niviventer confucianus and N. fulvescens

The status of Niviventer confucianus and N. fulvescens as separate species or color variants of the same species has been debated for a long time. A detailed study of 157 specimens (119 N. confucianus and 34 N. fulvescens) collected 1937/1938 in Fukien, South East China, was conducted in order to shed more light on the taxonomic status of the two taxa. Because all measured skull parameters strongly correlate with age, age classes were formed on the basis of tooth wear. Student's t-tests for differences between N. confucianus and N. fulvescens were performed using age-independent unstandardized residuals. These were derived from linear regressions of each measured parameter against age class. Statistical significant differences between the taxa were revealed in residuals based on interorbital constriction, length and width of incisive foramen, length of bulla, diastema, width of rostrum and width of nasal. Discriminant analysis using the unstandardized residuals shows a clear separation between N. confucianus and N. fulvescens on the basis of the first discriminant function mainly influenced by interorbital width and length of incisive foramen. Additionally, qualitative morphological differences in the skulls are described, concerning the anterior rim of the zygomatic plate, the mandible and the maxillary teeth. The differences in outer morphology including the brighter, more reddish and more shiny pelage of N. fulvescens, white tail tip occurring in N. confucianus only, the relatively longer tail in N. confucianus, and the higher frequency of a fulvous marking on the chest in N. confucianus are supported.

Sexual dimorphism of craniological characters in Eurasian badgers, Meles spp. (Carnivora, Mustelidae)

An analysis of 30 craniological characters of Eurasian badgers ( Meles spp.) revealed different levels of sexual size dimorphism (SSD) and geographic variation in the three different species. SSD is displayed mostly in the general size of the skull (condylobasal length, zygomatic width, width of rostrum, and cranial height) and mandible (height of the vertical mandibular ramus, total length of the mandible, and length between the angular process and infradentale), and in some dental characters (length of the upper molar M 1). The most stable size dimorphism is manifested in the size of the canines, which is pronounced in all studied samples. SSD is not apparent in the length of the auditory bulla, the postorbital width, the minimum palatal width, the length of the lower molar M 2, and the talonid length of the lower carnassial tooth M 1. In both the European badgers, Meles meles, and the Asian badgers, Meles leucurus, two geographic forms that differ in the degree of SSD have been found. The most pronounced SSD of cranial characters is found in the Transcaucasian form of Meles meles and the Far-Eastern form of Meles leucurus. In the large European form of Meles meles, SSD is less pronounced in both absolute and relative criteria than in the smaller Transcaucasian form. An analogous situation is observed in the larger Siberian and smaller Far-Eastern forms of Meles leucurus. In the Japanese badgers, Meles anakuma, a downsizing of the skull is accompanied by a decrease in SSD (except in canine size) in comparison to the continental species. The significant differences in the manifestation of SSD in the Eurasian badgers support an earlier hypothesis (Abramov, 2001. Proc. Zool. Inst. Russ. Acad. Sci. 288, 221–233; Abramov, 2002. Russ. J. Theriol. 1 (1), 57–60; Abramov, 2003. Small Carnivore Conserv. 29, 5–7) that Meles meles, Meles leucurus, and Meles anakuma are separate species. The differences in the level of SSD among and within these three species of badgers may be attributed not to differences in the diet or social structure, but to the history of speciation events and formation of intraspecific distribution ranges.

Redescription of a rare deep-sea batfish, Halieutopsis bathyoreos (Lophiiformes: Ogcocephalidae)

Halieutopsis bathyoreos Bradbury, 1988 (Lophiiformes: Ogcocephalidae), previously described only on the basis of the holotype (62.6 mm in standard length) from the central North Pacific, is redescribed on the basis of the holotype and six additional specimens (41.2–68.7 mm in standard length) collected from the western South Pacific, off Papua New Guinea, and the western North Pacific, including the Japanese Archipelago. Halieutopsis bathyoreos is distinguished from its congeners by having a shelflike rostrum extending anteriorly well beyond the mouth, a dorsal escal lobe slightly bisected ventrally, an illicial cavity square in outline and completely visible in ventral view, and lacking tubercles on the ventral surface of the disk. The following characters are newly added to the diagnoses of this species: rostrum width 21–29% of head length, tubercles on the dorsal surface of the disk about half the diameter of those on the lateral margin, and 13–15 large lateral-line scales on the tail.

TOWARDS IDENTIFICATION OF THE ECOLOGICAL LIFESTYLE IN NEKTONIC SQUID USING STATOLITH MORPHOMETRY

Nine morphometric parameters of statolith parts were studied in eight nektonic squid having different lifestyles: Berryteuthis magister, Berryteuthis anonychus, Gonatus berryi, Gonatus fabricii, Gonatopsis borealis (all Gonatidae), Loligo gahi (Loliginidae), Todarodes sagittatus (Ommastrephidae) and Moroteuthis ingens (Onychoteuthidae). Five parameters (indices of the free part of the rostrum, wing length and width, rostrum width relative to total statolith length and total statolith length relative to mantle length) were found to be specific for near-bottom versus pelagic species in all families studied; one parameter (index of dorsal dome length) was highly conservative among all gonatids. Possible reasons for such patterns among the indices are discussed based on current understanding of statolith function. Analysis of both morphological and morphometric parameters of statoliths allows inferences to be made about the ecological lifestyle of both Recent and extinct species of squid belonging to the same family. Using these parameters, it is suggested that an extinct species of Berryteuthis identified from Pliocene deposits in California had a lifestyle intermediate between the near-bottom B. magister and its more pelagic counterpart B. anonychus. Statoliths of another extinct squid, Moroteuthis addicotti, resembled both in shape and size those of young B. magister, suggesting the possibility that M. addicotti is a synonym of Berryteuthis sp.