Some new and known species of Bomolochidae (Copepoda, Cyclopoida) parasitic on Japanese actinopterygian fishes, 1 — with discussion on sexually dimorphic features in the family

Crustaceana ◽  
2020 ◽  
Vol 93 (8) ◽  
pp. 891-929
Author(s):  
Kunihiko Izawa
Keyword(s):  
Sexual Dimorphism ◽  
Sexually Dimorphic ◽  
The Family ◽  
Actinopterygian Fishes ◽  
Copepoda Cyclopoida

Abstract Three new and five known species of Bomolochidae Claus, 1875, parasitic on Japanese actinopterygian fishes, are (re)described. They are Bomolochus bellones Burmeister, 1835, B. decapteri Yamaguti, 1936, B. hoi sp. nov., Naricolax sphyraenae sp. nov., Nothobomolochus cypseluri (Yamaguti, 1953), Orbitacolax brevispinus Moon, Choi & Venmathi Maran, 2018, O. scombropsi sp. nov., and O. unguifer Kim & Moon, 2013. The copepodid IV female of B. bellones, the male and copepodid IV female of Na. sphyraenae, the male and copepodid IV and V female of No. cypseluri and O. unguifer are herein described. Sexual dimorphism is found in the antennule, maxilliped, and legs in the family.

An interesting sexually dimorphic species, Neoribates isabelaensis sp. nov. (Acari, Oribatida, Parakalummidae) with remarks on sexual dimorphism in Oripodoidea 

Zootaxa ◽  
2017 ◽  
Vol 4347 (1) ◽  
pp. 94
Author(s):  
BADAMDORJ BAYARTOGTOKH ◽  
SERGEY G. ERMILOV ◽  
LEONILA CORPUZ-RAROS
Keyword(s):  
Sexual Dimorphism ◽  
Posterior Part ◽  
The Philippines ◽  
Similar Species ◽  
Sexually Dimorphic ◽  
The Family ◽  
Pheromonal Communication ◽  
Large Round ◽  
Dimorphic Species ◽  
A New Species

A new species Neoribates isabelaensis sp. nov. showing an interesting sexual dimorphism is described from bamboo litter on Luzon Island in the Philippines. This species is unique among other species of Neoribates in the structure of the posterior part of notogaster in males, which has a large round concavity bearing a pair of large sacculi S3. The specific function of this structure is not yet known, but the found sexual dimorphism is presumably involved in pheromonal communication allowing rapid sperm transfer. This is the fourth Neoribates species displaying sexually dimorphic characters. Additionally, Neoribates isabelaensis sp. nov. differs from the morphologically most similar species, Neoribates barbatus Hammer, 1968, by its smaller body size, pointed rostrum, long and setiform bothridial setae and the localization of notogastral setae h1 and h2, which insert close to each other. Further, we discussed all cases of sexual dimorphism in the family Parakalummidae as well as other related groups of Oripodoidea, and the possible function of these modifications. 

Diverse Texas beetles (Coleoptera: Elateroidea: Brachypsectridae) in mid-Cretaceous Burmese amber: sexual dimorphism and palaeoecology

2019 ◽  
Vol 2 (5) ◽  
pp. 523-531 ◽  
Author(s):  
ERIK TIHELKA ◽  
DIYING HUANG ◽  
CHENYANG CAI
Keyword(s):  
Sexual Dimorphism ◽  
Posterior Margin ◽  
New Genus ◽  
Distribution Range ◽  
Disjunct Distribution ◽  
Sexually Dimorphic ◽  
Fossil Species ◽  
Burmese Amber ◽  
The Family

Brachypsectridae is a species-poor elateroid family containing two extant genera with a disjunct distribution range spanning the Nearctic, Palaearctic, Oriental, and Australian regions. Here we describe a second Texas beetle from mid-Cretaceous Burmese amber, Hongipsectra electrella gen. et sp. nov. The new genus can be distinguished from all hitherto known brachypsectrids by the 11-segmented sexually dimorphic antennae with antennomeres 6–10 bilamellate in males and serrate in females, pronotum with a pair of posterolateral carinae and an M-shaped notch in the posterior margin for the reception of a cordiform scutellum. The present discovery adds a fourth genus and eleventh species to Brachypsectridae. Given that two of the known Texas beetle genera are from the Cretaceous Burmese amber, the family probably have been much more widespread and diverse in the Mesozoic than it is today. A key to the extant and fossil genera of Brachypsectridae is provided, along with a list of fossil species.

Cranial morphology and osteology of the sexually dimorphic electric fish, Compsaraia samueli Albert & Crampton (Apteronotidae, Gymnotiformes), with comparisons to C. compsa (Mago-Leccia)

Zootaxa ◽  
2019 ◽  
Vol 4555 (1) ◽  
pp. 101 ◽  
Author(s):  
RACHEL KEEFFE ◽  
ERIC J. HILTON ◽  
MÁRIO J. F. THOMÉ DE SOUZA ◽  
CRISTINA COX FERNANDES
Keyword(s):  
Sexual Dimorphism ◽  
The Body ◽  
Cranial Morphology ◽  
Sexually Dimorphic ◽  
Anterior Portion ◽  
Lower Jaw ◽  
Wide Range ◽  
The Family ◽  
Body Sizes ◽  
Cranial Osteology

Sexual dimorphism of the snout has evolved independently in at least four separate clades of the gymnotiform family Apteronotidae. This phenomenon may help identify sex, except in the absence of mature individuals, and has led to confused taxonomy for several species. We examined a large collection of Compsaraia samueli collected during the breeding season from a remote stream in the Rio Negro drainage. This collection contains a wide range of sizes of both sexes, but most individuals were easily identified as mature. To quantify the sexual dimorphism of these specimens, 15 measurements were taken from the head and the body. In addition, some specimens were cleared-and-stained to study cranial osteology. We found that long-snouted males of C. samueli span a wide range of body sizes. As the snout length increases the distance between the eye and the occiput does not increase at the same rate, suggesting that it is only the anterior portion of the head that has an increased allometry. Skeletal anatomy differs between the sexes in that the lower jaw is more triangular in females and more linear in males. The coronomeckelian is small and round in females in contrast to being longer and pointed in males. There is strong interlacing of the dentary and anguloarticular bones in males, whereas this contact is not as extensive in females. We also discuss the implications of sexual dimorphism for identification of this species relative to its congener (C. compsa), and for the evolution of sexual dimorphism in the family. 

scholarly journals Morphology and ecology of a new sexually dimorphic species of Polydora (Polychaeta: Spionidae) associated with hermit crabs from Jamaica, West Indies

Zoosymposia ◽  
2009 ◽  
Vol 2 (1) ◽  
pp. 229-240 ◽  
Author(s):  
LARA D. ORENSKY ◽  
JASON D. WILLIAMS
Keyword(s):  
Sexual Dimorphism ◽  
West Indies ◽  
Hermit Crabs ◽  
Large Female ◽  
Sexually Dimorphic ◽  
The Third ◽  
Commensal Species ◽  
The Family ◽  
Shallow Subtidal ◽  
Dimorphic Species

A new commensal species of Polydora was found associated with hermit crabs from shallow subtidal coral reefs in Jamaica, West Indies, in 2005 and 2006. Polydora nanomon sp. nov. is the third known obligate commensal polydorid of hermit crabs. The species is found in approximately 20% of the gastropod shells, most commonly Leucozonia nassa leucozonalis (Lamarck, 1822), inhabited by Calcinus tibicen (Herbst, 1791) and other hermit crab hosts. P. nanomon sp. nov. produces a hole in the apex of the shell, enters the lumen of the uppermost whorl, and connects to the columella with a tube of mucus and detritus. One large female (up to 70 setigers) is found in the apex with up to four smaller males (generally <30 setigers). Females are distinguished from other species of Polydora by the morphology of the major spines of setiger 5. In addition to a horizontal row of major spines with two lateral teeth, companion setae, and ventral capillaries, setiger 5 contains a group of superior accessory spines, including one large falcate spine with a channel extending down the shaft, one spine with a low rounded tooth, and one companion seta. P. nanomon sp. nov. exhibits sexual dimorphism with the males being much smaller than females, having a reduced first segment, and lacking accessory spines on setiger 4 (= setiger 5 on females). The occurrence of sexual dimorphism within the family Spionidae is reviewed.

Two new marine cyclopinids (Crustacea: Copepoda: Cyclopoida) from interstitial habitats in Korea

Zootaxa ◽  
2021 ◽  
Vol 5051 (1) ◽  
pp. 319-345
Author(s):  
TOMISLAV KARANOVIC
Keyword(s):  
Sandy Beaches ◽  
Sexually Dimorphic ◽  
Exopodal Segment ◽  
The Family ◽  
Anchialine Caves ◽  
The Antarctic ◽  
First Time ◽  
Marginal Habitats ◽  
Copepoda Cyclopoida

Marine cyclopoids, and especially cyclopinids, are poorly studied because their diversity is highest in marginal habitats, such as intertidal interstitial and anchialine caves, or in highly inaccessible abyssal and hadal depths. Two new cyclopinids are described here, both from two different sandy beaches in Korea. Among four species currently recognized in the genus, Heterocyclopina koreaensis sp. nov. is most closely related to H. vietnamensis Pleşa, 1969 from similar habitats in Vietnam. Koreacyclopina wellsi gen. et sp. nov. shares its sexually dimorphic third exopodal segment of the second leg with the Antarctic genus Pseudocyclopina Lang, 1946, but differs from all six known species by numerous features, some of which are observed for the first time within cyclopinids. Both Korean species belong to the family Hemicyclopinidae, but the monophyly of this group has not yet been demonstrated.  

scholarly journals X chromosome escapee genes are involved in ischemic sexual dimorphism through epigenetic modification of inflammatory signals

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Shaohua Qi ◽  
Abdullah Al Mamun ◽  
Conelius Ngwa ◽  
Sharmeen Romana ◽  
Rodney Ritzel ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
X Chromosome ◽  
Epigenetic Modification ◽  
Artery Occlusion ◽  
Sexually Dimorphic ◽  
Mrna Levels ◽  
Young Females ◽  
Human Stroke ◽  
Histone H3k4 ◽  
Cerebral Artery Occlusion

Abstract Background Stroke is a sexually dimorphic disease. Previous studies have found that young females are protected against ischemia compared to males, partially due to the protective effect of ovarian hormones, particularly estrogen (E2). However, there are also genetic and epigenetic effects of X chromosome dosage that contribute to stroke sensitivity and neuroinflammation after injury, especially in the aged. Genes that escape from X chromosome inactivation (XCI) contribute to sex-specific phenotypes in many disorders. Kdm5c and kdm6a are X escapee genes that demethylate H3K4me3 and H3K27me3, respectively. We hypothesized that the two demethylases play critical roles in mediating the stroke sensitivity. Methods To identify the X escapee genes involved in stroke, we performed RNA-seq in flow-sorted microglia from aged male and female wild type (WT) mice subjected to middle cerebral artery occlusion (MCAO). The expression of these genes (kdm5c/kdm6a) were confirmed in four core genotypes (FCG) mice and in post-mortem human stroke brains by immunohistochemistry (IHC), Western blot, and RT-PCR. Chromatin immunoprecipitation (ChIP) assays were conducted to detect DNA levels of inflammatory interferon regulatory factor (IRF) 4/5 precipitated by histone H3K4 and H3K27 antibodies. Manipulation of kdm5c/kdm6a expression with siRNA or lentivirus was performed in microglial culture, to determine downstream pathways and examine the regulatory roles in inflammatory cytokine production. Results Kdm5c and kdm6a mRNA levels were significantly higher in aged WT female vs. male microglia, and the sex difference also existed in ischemic brains from FCG mice and human stroke patients. The ChIP assay showed the IRF 4/5 had higher binding levels to demethylated H3K4 or H3K27, respectively, in female vs. male ischemic microglia. Knockdown or over expression of kdm5c/kdm6a with siRNA or lentivirus altered the methylation of H3K4 or H3K27 at the IRF4/5 genes, which in turn, impacted the production of inflammatory cytokines. Conclusions The KDM-Histone-IRF pathways are suggested to mediate sex differences in cerebral ischemia. Epigenetic modification of stroke-related genes constitutes an important mechanism underlying the ischemic sexual dimorphism.

Some new and known species of Bomolochidae (Copepoda, Cyclopoida) parasitic on Japanese actinopterygian fishes, 3

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 447-465
Author(s):  
Kunihiko Izawa
Keyword(s):  
Male Specimen ◽  
Actinopterygian Fishes ◽  
Dorsal Process ◽  
First Time ◽  
Respective Species ◽  
Copepoda Cyclopoida

Abstract Orbitacolax bispinus sp. nov., Orbitacolax leptoscari (Yamaguti, 1953), Paraorbitacolax sphyraenae Izawa, 2021, and one male specimen of a Bomolochidae sp. are (re)described. The male and copepodid V female of O. leptoscari, and the male and copepodid V male of P. sphyraenae are described for the first time for the respective species. A description performed in Izawa (2020, 2021) that the maxilliped of the female bears a dorsal process in Orbitacolax and Paraorbitacolax spp., was wrong and is herein corrected.

The melanocortin-3 receptor is a pharmacological target for the regulation of anorexia

2021 ◽  
Vol 13 (590) ◽  
pp. eabd6434
Author(s):  
Patrick Sweeney ◽  
Michelle N. Bedenbaugh ◽  
Jose Maldonado ◽  
Pauline Pan ◽  
Katelyn Fowler ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Feeding Behavior ◽  
Critical Role ◽  
Brain Regions ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Female Mice ◽  
Bidirectional Regulation ◽  
Fear And Anxiety ◽  
Agouti Related Protein

Ablation of hypothalamic AgRP (Agouti-related protein) neurons is known to lead to fatal anorexia, whereas their activation stimulates voracious feeding and suppresses other motivational states including fear and anxiety. Despite the critical role of AgRP neurons in bidirectionally controlling feeding, there are currently no therapeutics available specifically targeting this circuitry. The melanocortin-3 receptor (MC3R) is expressed in multiple brain regions and exhibits sexual dimorphism of expression in some of those regions in both mice and humans. MC3R deletion produced multiple forms of sexually dimorphic anorexia that resembled aspects of human anorexia nervosa. However, there was no sexual dimorphism in the expression of MC3R in AgRP neurons, 97% of which expressed MC3R. Chemogenetic manipulation of arcuate MC3R neurons and pharmacologic manipulation of MC3R each exerted potent bidirectional regulation over feeding behavior in male and female mice, whereas global ablation of MC3R-expressing cells produced fatal anorexia. Pharmacological effects of MC3R compounds on feeding were dependent on intact AgRP circuitry in the mice. Thus, the dominant effect of MC3R appears to be the regulation of the AgRP circuitry in both male and female mice, with sexually dimorphic sites playing specialized and subordinate roles in feeding behavior. Therefore, MC3R is a potential therapeutic target for disorders characterized by anorexia, as well as a potential target for weight loss therapeutics.

scholarly journals A new species of sexually dimorphic Pareiorhaphis Miranda Ribeiro, 1918 (Siluriformes: Loricariidae) from the rio Doce basin, Brazil

2007 ◽  
Vol 5 (4) ◽  
pp. 443-448 ◽  
Author(s):  
Edson H. L. Pereira ◽  
Fábio Vieira ◽  
Roberto E. Reis
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Minas Gerais ◽  
Sexually Dimorphic ◽  
The Family ◽  
A New Species

Pareiorhaphis nasuta, a new neoplecostomine catfish of the family Loricariidae is described. The species was collected from headwaters of the rio Matipó, tributary of the upper rio Doce basin in State of Minas Gerais, Brazil. The new species is readily diagnosed from all remaining congeners by the longer snout and by the smaller orbital diameter. The new species is the first representative of the genus Pareiorhaphis discovered in the rio Doce basin, thus expanding its geographic distribution. A phylogenetic diagnosis for Pareiorhaphis is presented.

Sexual dimorphism in the antennae of terrestrial isopods: a result of male contests or scramble competition?

2000 ◽  
Vol 78 (11) ◽  
pp. 1987-1993 ◽  
Author(s):  
F Lefebvre ◽  
M Limousin ◽  
Y Caubet
Keyword(s):  
Sexual Dimorphism ◽  
Negative Correlation ◽  
Morphological Analysis ◽  
Scramble Competition ◽  
Behavioral Analysis ◽  
Sexually Dimorphic ◽  
Selection Pressures ◽  
Terrestrial Isopods ◽  
Male Contests

In Oniscidea (terrestrial crustaceans), males are known to have longer antennae than females. This sexual dimorphism may result from a variety of selection pressures. However, some species are well known for their highly aggressive males, which use their antennae as weapons. We tested the hypothesis that longer antennae in males have been selected for by means of antennal contests. Morphological analysis of the antennae and behavioral analysis of male dyads were performed in parallel on 7 species. We demonstrate significant sexual dimorphism of the antennae in 6 of the 7 species, and various forms of male aggressiveness depending on the species. Our hypothesis was rejected because we found a negative correlation between the use of the antennae in contests and the magnitude of sexual dimorphism. Furthermore, some species are sexually dimorphic but the males never compete using their antennae. We propose and argue that scramble competition to be the first to find receptive females could explain why males have longer chemoreceptive antennae.

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