Male Specimens Research Articles

Ecogeographic rules in a common Neotropical treefrog: No clinal variation along a mountain range

AbstractBody and limb size are associated with many aspects of the biology of animals. Geographic variation in morphological traits has often been investigated through ecogeographical rules. Bergmann's rule posits an inverse relationship between body size and temperature in homeotherms, while Allen's rule posits that endothermic animals inhabiting colder climates have relatively shorter protruding parts (e.g., limbs) in comparison to populations from warmer climates. However, the applicability and validity of these rules in poikilotherms are currently contentious. In this study, we aimed to test predictions of Bergmann's and Allen's rules in populations of the Neotropical frog Boana platanera. We analysed 142 adult male museum specimens from 17 localities along a mountain range in western Venezuela. We obtained six external morphological measurements and assessed the correlation of body size and limb size with temperature data for each locality. Our results were contrary to the expectations but consistent with previous studies. All this together indicates that exceptions to the Bergmann's and Allen's rules are frequent and idiosyncratic in anurans. We discuss alternative hypotheses that could explain geographic variation of body and limb size in future studies.

Sexual dimorphism in the genus Acothrura Melichar, 1915 (Hemiptera: Lophopidae) and description of male and female specimens of A. impunctata (Jacobi, 1905)

The sexual dimorphism of Acothrura impunctata (Jacobi, 1905) is confirmed by molecular analysis. Its male morphological characteristics are firstly reported. A key to species of Acothrura is provided.  

The mylohyoid line is highly variable but does not affect the microarchitecture of the edentulous alveolar bone – an anatomical micro-CT study

ObjectivesTo evaluate in the absence of teeth the variability of the mylohyoid line (ML), the microarchitecture of the adjacent bone, and whether the variable prominence/width of the ML is associated with the quality of the adjacent bone.MethodsµCT scans of 28 human mandibles from anatomical specimens were analyzed. The following parameters were assessed in four edentulous areas (first and second premolar (PM), first, second, and third molar (M1/2/3)): ML width, cortical thickness (CtTh), average cortical- (Avg.Ct.BV/TV), and trabecular bone volume fraction (Avg.Tb.BV/TV).ResultsThe ML width increased from the PM towards the M2 region, which also showed the highest variance (range: 0.4–10.2 mm). The CtTh showed a decrease in the M3 region, while Avg.Ct.BV/TV and Avg.Tb.BV/TV hardly differed among the regions. In the multivariable model on the effect of the various parameters on the ML width, only gender and tooth region were significant. Specifically, male specimens were associated with a wider ML width compared to female specimens and the M2 region was associated with a wider ML width compared to the other tooth regions.ConclusionThe ML width was not associated with the cortical and trabecular bone quality in the adjacent bone, while gender and tooth region had a significant effect. Specifically, the ML width was lower in female, but peaked in the M2 region with a median width of 3–4 mm.Clinical relevanceFrom a clinical point of view, it was confirmed that the ML is in general a highly variable structure, especially in the M2 region, but the ML width does not allow any conclusions on the bone quality. Altogether, this underlines the need for an individual and accurate diagnostic prior to any surgical intervention.

Nueva localidad de registro del cangrejo de agua dulce Pseudothelphusa terrestris (Decapoda: Pseudothelphusidae) para Jalisco, México

The freshwater crab Pseudothelphusa terres-tris is one of the 29 species of the genus Pseudothelphusa recorded in Mexico. The spe-cies was first described and recorded on Atemajac de Brizuela (type locality), Jalisco in 1893. Until now, the species is only known from six localities: one in Jalisco, and five in Nayarit. Herein, a new locality record of P. terrestris from Jalisco (second state record) is presen-ted based on a revision of adult male specimen (cara-pace width = 28.63 mm, carapace length = 17.12 mm) collected in San Sebastián del Oeste.

Histological aspects of the renal sexual segment of Brazilian snakes of the Boidae family.

Snakes represent a wide and diverse group of species and have anatomical particularities, such as the renal sexual segment (RSS), a structure located in the kidneys and formed from the hypertrophy of the urinary ducts and nephrons. This study aims at describing the histological aspects of the RSS of Boa constrictor, Epicrates cenchria and Corallus hortulanus, all of which are Brazilian snake species from the Boidae family. The reproductive system and kidneys of five male specimens of E. cenchria, three male specimens of C. hortulanus and two male specimens of B. constrictor were obtained. Tissue samples were processed histologically and different stains used (Toluidine Blue, Alcian Blue and Periodic Acid Schiff). The histological evaluation of the RSS of E. cenchria, C. hortulanus and B. constrictor shows that the RSS in these species varies when comparing individuals in the reproductive period with those which are not. It also allows for the observation of the segment's secretory activity in animals in the reproductive stage (mature sperm in the lumen of the seminiferous tubules) as well as in those which are not. Finally, the histological evaluation also reveals the variation of the secretion product in individuals in the reproductive period, in those which are not, and also among individuals within the same reproductive stage.

The Gould’s Toucanet Selenidera gouldii (Natterer, 1837) (Aves: Ramphastidae) as a monotypic species

The Gould’s Toucanet Selenidera gouldii (Natterer, 1837) occurs mainly in eastern Amazonia, with a geographically isolated population in the northeast Brazilian state of Ceará. Based on two male specimens from the latter population that appeared to have a smaller body and bill with a relatively large black patch, Pinto & Camargo (1961) described the subspecies S. g. baturitensis. This taxon has long been known in museum collections only by the two male specimens mentioned in its description, but recently obtained specimens have now permitted a test of its validity with larger sample sizes. Here, I examined the largest sample of S. g. baturitensis studied to date to show that S. g. gouldii and S. g. baturitensis are just the east and west ends of a broad geographic pattern of smoothly clinal differences in morphometrics that were categorized as subspecies taxa.

New records of Micromegistus bakeri, Trägårdh 1948 (Acari: Mesostigmata: Parantennulidae), a mite symbiotic on carabid beetles, and notes on the species’ distribution and host specificity

Micromegistus bakeri is a purported commensal mite that spends most of its life on the ground beetle Scarites subterraneus. It is thought to sustain itself by feeding on the beetle’s dermal fluids and opportunistically scavenging on nearby organic debris, although the nature of this relationship, and whether it’s beneficial, detrimental or neutral to the host, is unclear. This species has previously been recorded in Mississippi, Texas, and Kansas. This study reports the first record of M. bakeri in Pennsylvania based on our collecting, as well as the first records for Ohio, Michigan, Missouri, Arizona, and Canada, based on previously unpublished museum records. The literature and our own survey of carabid beetles indicate that M. bakeri has a strong preference for S. subterraneus as a host and is not common on other carabids. Our own data shows a prevalence of 27% of S. subterraneus (10 out of 37) carrying M. bakeri, with an average of 3.1 (range 1–8) mites per infested beetle; none of the other 31 carabid species collected during this study carried M. bakeri. This study represents the first publicly available COI barcode sequence for this taxon. We also provide photographs of live mites and summarize suspected sightings from additional locations across North America obtained via the citizen science websites BugGuide and iNaturalist. These records indicate that M. bakeri is present throughout the known distribution of its beetle host. Suspected M. bakeri were observed on other Scarites species in North America, but their presence on these hosts needs to be confirmed via examination of physical specimens. It should be noted that the westernmost record for the species is in Arizona, based on a male specimen that exhibits 6.6% divergence in COI barcode sequence with specimens from Pennsylvania. The specimen is otherwise essentially morphologically identical to males of eastern USA, and it is therefore uncertain whether it represents a cryptic species or merely high intraspecific genetic divergence over a large geographic distance.

A new Psammitis species (Araneae, Thomisidae) from an extinct volcano in Georgia with reevaluation of the generic position of Xysticus marmoratus Thorell, 1875

A new species, Psammitis abuliensissp. nov., from Didi Abuli Mt. (Georgia, Samtskhe-Javakheti region), is described based on two male specimens. Diagnostic drawings, measurements, collecting data, diagnosis, and DNA barcodes are given. A new combination, Psammitis marmoratus (Thorell, 1875), comb. nov. (ex. Xysticus), is proposed based on the COI subunit barcode results and morphological characters.

Length-weight relationships and biometry analysis of saddled seabream, Oblada melanurus (Linnaeus, 1758) in İzmir Bay (Central Aegean Sea of Türkiye)

The present study presents length-weight, length-length, length-girth relationships, and biometry of male and female specimens of saddled seabream, Oblada melanurus(Linnaeus, 1758), in the Turkish Aegean Sea. The length-length and length-weight relationships were calculated by measuring 516 individuals. The total length values of all male and female O. melanurus specimens were in the range of 17.2-30.7 and 18.5-30.0 cm, respectively, and the mean values were 21.84±2.04 and 22.44±2.12 cm, respectively. The length-weight relationships were W=0.0110TL3.057 for males, W=0.0114TL3.043 for females, and W=0.0089TL3.122 for all the specimens. The results denoted a high correlation (r²=0.966; p<0.001) in the length-length relationships. Furthermore, 287 individuals (105 females and 182 males) were examined for length-girth relationships and biometric analyses. Ten morphometric characters were analyzed to analyze biometry. In conclusion, no statistically significant differences were determined in morphology between the sexes (p<0.05).

Redescription and a significant range extension of Rhacophorus napoensis Li, Liu, Yu & Sun, 2022 (Amphibia, Anura, Rhacophorinae) with the first record from Vietnam

The Napo Treefrog Rhacophorus napoensis was described based on five male specimens from Napo County, Baise City, Guangxi Autonomous Region, China. Herein, we report on new findings and a range extension of this species based on an examination of preserved specimens collected from Bac Giang and Nghe An provinces, Vietnam. Futhermore, molecular analyses of specimens Rhacophorus spp. previously identified as R. rhodopus that were reported in Bac Giang, Nghe An as well as Thanh Hoa, and Ha Tinh provinces based on mitochondrial DNA supported the morphological findings. The Vietnam specimens have a pairwise divergence of less than 2% from those of the type series of Rhacophorus napoensis (based on the 16s rRNA mtDNA gene). Based on the new information, we confirm the presence of R. napoensis in Vietnam and update the diagnostic characters of this species and distribution. We suggest the species should be considered as of Least Concern (LC) following the IUCN’s Red List categories. Further studies reassessing the populations of the Rhacophorus bipunctatus complex are required.

From sabers to spikes: A newfangled reconstruction of the ancient, giant, sexually dimorphic Pacific salmon, †Oncorhynchus rastrosus (SALMONINAE: SALMONINI).

The impressive †Oncorhynchus rastrosus of the Pacific Northwest's Miocene and Pliocene eras was the largest salmonid ever to live. It sported a hypertrophied premaxilla with a pair of enlarged teeth which the original describers reconstructed as projecting ventrally into the mouth, leading them to assign the species to "Smilodonichthys," a genus now in synonymy. Through CT reconstruction of the holotype and newly collected specimens, we demonstrate that the famed teeth projected laterally like tusks, not ventrally like sabers or fangs. We also expand the original description to characterize sexual dimorphism in mature, breeding individuals. Male and female †Oncorhynchus rastrosus differ in the form of the vomer, rostro-dermethmoid-supraethmoid, and dentary, much as do other extant species of Oncorhynchus. Male specimens possess a more elongate vomer than do females, and female vomers have concave ventral surfaces and prominent median dorsal keels. The dentary of females has no evidence of a kype, though some specimens of †O. rastrosus have a non-uniform density mesial to the tooth bed, which we interpret as a male kype. Unlike extant Oncorhynchus, male and female †O. rastrosus do not differ in premaxilla shape. Because male and females possess hypertrophied premaxillae and lateral premaxillary spikes, the former common name "Sabertoothed Salmon" no longer reflects our understanding of the species' morphology. Accordingly, we redub †O. rastrosus the Spike-Toothed Salmon and postulate that its spikes were multifunctional, serving as defense against predators, in agonism against conspecifics, and as a practical aid to nest construction.

Morphometric Studies of Tobacco Caterpillar, [Spodoptera litura (Fabricius)] on Different Host Plants

Tobacco caterpillar, Spodoptera litura (Fabricius) is an economically important polyphagous pest inflicting significant economic damage to numerous field and horticultural crops. Research was conducted at the Department of Entomology, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, in laboratory settings to validate the presence of this pest. The investigation involved detailed measurements of the various larval stages, pupa, adult male, and female, of tobacco caterpillar including the wingspan. The first to sixth instars of S. litura exhibited significantly greater length and width as well as width of head capsule, when reared on the tomato as a host. The pupae of S. litura reached at their maximum length and width when raised on marigold (16.75 mm and 4.36 mm), while the minimum pupal measurements (14.10 mm and 4.42 mm) was observed in case of maize. In regards to the adult moths, both male and female specimens displayed the longest length and wing span when associated with tomato (16.71 mm and 18.22 mm for length, 38.47 mm and 38.73 mm for wingspan, respectively), whereas the smallest measurements were recorded for those associated with maize (14.35 mm and 16.95 mm for length, 35.10 mm and 35.12 mm wingspan respectively). The present study confirmed the presence of S. litura that require immense attention to prepare the management strategy against it.

Rare case of divided phrenic nerve variation: a cadaveric case report.

The phrenic nerve innervates the respiratory diaphragm, the primary muscle active during ventilation. The canonical path of the phrenic nerve originates from the cervical spine at C3-C5 spinal nerves and travels inferiorly through the neck and thoracic cavity to reach the diaphragm. During a cadaver dissection, a variation of the phrenic nerve was discovered in a 93-year-old male specimen. A traditional origin of the phrenic nerve was noted; however, the nerve branched into medial and lateral components at the level of the superior trunk of the brachial plexus. The branches reconnected at the apex of the aortic arch and continued inferiorly to innervate the ipsilateral diaphragm. This case study describes a rare type of branching of the phrenic nerve and explores its potential impact on clinical procedures.

An enigmatic Anthophorine bee from the south of France revealed as a new species: Anthophora (Paramegilla) ahlamae n. sp. (Hymenoptera: Apidae)

Summary A bee specimen identified as Anthophora planca Pérez, 1895, from France, was discovered in collections of Museum für Naturkunde, Berlin. This male specimen presents a morphology that does not conform to any of the Anthophora Latreille, 1803 species known from France, or indeed from Europe. After careful examination, it cannot be identified as Anthophora planca Pérez which is considered to be a nomen dubium (type lost), but furthermore it does not belong to any currently described species. Additional specimens of this species were collected in Morocco, Spain (Melilla) and Algeria. The new species is named Anthophora (Paramegilla) ahlamae Rasmont & Wood, n. sp. The new species is documented by numerous high-resolution photographs. Its diagnosis is compared with the near species Anthophora (Paramegilla) gallica (Dalla Torre & Friese, 1895) and A. (Paramegilla) podagra Lepeletier, 1841. DNA barcodes data are presented, allowing for confirmation of placement within the subgenus Paramegilla Friese, 1897. A detailed distribution map is provided along with ecological observations. Anthophora ahlamae n. sp. may be specialised on flowers of the genus Ballota L. (Lamiaceae).

A new species of Pristerophora Harold, 1869 (Coleoptera: Scarabaeidae: Melolonthinae) from Chile

A new species of Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae), Pristerophora rothmanni new species, is described and illustrated based on male and female specimens collected in southern Chile. Natural history, habitat, and distributional data are given. An identification key for Pristerophora species is included.

Primer registro de Bisaltes (Bisaltes) brevicornis Breuning, 1939 (Coleoptera: Cerambycidae: Lamiinae: Apomecynini) en Perú, con notas sobre otras especies peruanas de Bisaltes (s. str.) Thomson, 1868

We present the first record of Bisaltes (Bisaltes) brevicornis Breuning, 1939 in Peru, based on one male specimen collected in an urban locality of the Lambayeque region in northwestern Peru. A diagnosis for recognition of the species and differentiate it from other similar taxa are provided. Additionally, notes regarding other species of Bisaltes (Bisaltes) Thomson, 1868 recorded to Peru are given.

Complementary description of Lasioseius thermophilus Willmann, 1942 (Acari: Blattisociidae) based on the material collected from Iran

Lasioseius thermophilus Willmann, (Acari: Blattisociidae) was first described by Willmann in 1942 and then by Westeborer in 1963 based on one female specimen from Poland. Both descriptions are only based on female specimens and are not complete since they lack complete measurements of the setae, details of ventral shields, leg chaetotaxy and spermathecal apparatus. Therefore, the male specimen of this species is described and its female specimen is redescribed based on the materials collected from Guilan province, Iran.

First Description of Deutonymph Male of Eustigmaeus anauniensis (Canestrini) (Trombidiformes: Stigmaeidae)

With more than 130 species, Eustigmaeus Berlese is one of the most diverse genera in the family of Stigmaeidae.
 The genus has a worldwide distribution and is found in all zoogeographic regions with the exception of
 Antarctica. The adult female, adult male, deutonymph, protonymph, and larva of Eustigmaeus anauniensis
 (Canestrini) are known till now, but the immature male stage is unknown. In this study, five deutonymph male
 specimens of E. anauniensis were found in Türkiye. The description, illustrations of deutonymph males of E.
 anauniensis, and its measurements of some body parts were made. This is the first record of deutonymph male of E. anauniensis.

Phylogenetic evidence of a possible Trichuris globulosa species complex in Arabian camels from Kuwait.

During a 1-year study, Trichuris adults were obtained after necropsy of Arabian camels (Camelus dromedarius) from a slaughterhouse in Kuwait. Morphological and molecular identification was performed to confirm the identity of the Trichuris specimens obtained from C. dromedarius. Fifteen male Trichuris specimens were selected, and molecular identification was performed using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA, 16S ribosomal RNA genes and the nuclear internal transcribed spacer 2 (ITS2) region. Through phylogenetic analysis, 2 distinct groups were obtained using the mitochondrial genes, where group 1 showed a close relationship to Trichuris globulosa while group 2 showed a close relationship to Trichuris ovis, providing molecular evidence of a possible T. globulosa species complex. Additionally, the nuclear ITS2 region did not provide enough resolution to distinguish between the 2 groups of Trichuris specimens. Observation of morphological characters revealed variations in the shape of the male spicule sheath, where specimens present either a globular posteriorly truncated swelling or the absence of posteriorly truncated swelling. Moreover, the variations in male spicule sheath does not corroborate with the results of molecular data, suggesting the limited use of this character for identification of T. globulosa. In conclusion, molecular analysis suggests a possible species complex in T. globulosa, with the mitochondrial genetic markers successfully differentiating between the 2 groups. The limited use of the male spicule sheath as a diagnostic character for identification of T. globulosa is suggested.

Expansion of the Distribution Range and Size of the Invasive Blue Crab on the Turkish Coast of the Black Sea

The blue crab (Callinectes sapidus Rathbun, 1896) is an euryhaline species originally native to the western Atlantic Ocean. However, it has expanded its range into the Black Sea, including the Turkish coastal waters. Blue crab specimens were sampled along the Black Sea coast of Türkiye, covering the stretch from Cape Taşkana to the Georgian border. The monitoring studies spanned the period from 2017 to 2024. Analysis of the 16 specimens revealed a carapace width range of 14.8 to 20.3 cm, with males exhibiting larger sizes compared to females. Notably, two of the sampled females were observed to be carrying eggs, highlighting reproductive activity in the region. This study also reports the discovery of the largest blue crab ever recorded on the Turkish coasts of the Black Sea, with a male specimen measuring 20.33 cm in carapace width and weighing 565.1 g. Additionally, a male specimen sampled in the Rize region suggests the species has expanded its range to the easternmost part of the Black Sea. The findings contribute significantly to our understanding of the distribution and growth potential of the blue crab in the Black Sea. The larger sizes observed in males and the presence of ovigerous females indicate successful adaptation and potential establishment of a self-sustaining population. As invasive species, blue crabs can significantly influence benthic communities and food chains, highlighting the importance of a prudent management approach to fisheries biology and ecosystem management