Mesozoic origin and ‘out-of-India’ radiation of ricefishes (Adrianichthyidae)

The Indian subcontinent has an origin geologically different from Eurasia, but many terrestrial animal and plant species on it have congeneric or sister species in other parts of Asia, especially in the Southeast. This faunal and floral similarity between India and Southeast Asia is explained by either of the two biogeographic scenarios, ‘into-India’ or ‘out-of-India’. Phylogenies based on complete mitochondrial genomes and five nuclear genes were undertaken for ricefishes (Adrianichthyidae) to examine which of these two biogeographic scenarios fits better. We found that Oryzias setnai, the only adrianichthyid distributed in and endemic to the Western Ghats, a mountain range running parallel to the western coast of the Indian subcontinent, is sister to all other adrianichthyids from eastern India and Southeast–East Asia. Divergence time estimates and ancestral area reconstructions reveal that this western Indian species diverged in the late Mesozoic during the northward drift of the Indian subcontinent. These findings indicate that adrianichthyids dispersed eastward ‘out-of-India’ after the collision of the Indian subcontinent with Eurasia, and subsequently diversified in Southeast–East Asia. A review of geographic distributions of ‘out-of-India’ taxa reveals that they may have largely fuelled or modified the biodiversity of Eurasia.journal articl

Mitochondrial and nuclear phylogenetic trees and divergence time estimations of Sulawesi endemic Adrianichthyidae

This data article is related to the research article entitled “Origin and intra-island diversification of Sulawesi endemic Adrianichthyidae” by Mokodongan and Yamahira [1]. In this data article, we present phylogenetic trees of Sulawesi adrianichthyids separately reconstructed using mitochondrial (cytochrome b: cyt b and NADH dehydrogenase subunit 2: ND2) and nuclear (tyrosinase) sequences. We also present Bayesian chronograms of Sulawesi adrianichthyids separately estimated using a substitution rate for cyt b and for ND2

Data from: Genetic architecture of the variation in male-specific ossified processes on the anal fins of Japanese medaka

Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTLs with previously identified QTLs controlling anal fin length. First, we found that only a few QTLs were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays were often controlled by different QTLs. Finally, we produced another independent cross and found that some QTLs were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTLs that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTLs and have the potential for independent evolution

Data from: Evidence for hybridisation-driven heteroplasmy maintained across generations in a ricefish endemic to a Wallacean ancient lake

<p><span>Heteroplasmy, </span><span>the presence of multiple mitochondrial DNA (mtDNA) haplotypes within cells of an individual,</span><span> is caused by mutation or paternal leakage. However, heteroplasmy is usually resolved to homoplasmy within a few generations because of germ-line bottlenecks; therefore, instances of heteroplasmy are limited in nature. Here, we report </span><span>heteroplasmy in the ricefish species <em>Oryzias matanensis</em>, endemic to Lake Matano, an ancient lake in Sulawesi Island, in which one individual was known to have many heterozygous sites in the <span class="shorttext">mitochondrial NADH dehydrogenase subunit 2 (ND2) gene</span>. </span><span>In this study, </span><span>we cloned the ND2 gene for some additional individuals with heterozygous sites and demonstrated that they are truly heteroplasmic. Phylogenetic analysis revealed that the extra haplotype within the heteroplasmic <em>O. matanensis</em> individuals clustered with haplotypes of </span><em><span>O. marmoratus</span></em><span>, a congeneric species inhabiting adjacent lakes. This indicated that the heteroplasmy originated from paternal leakage due to interspecific hybridisation. </span><span>The extra haplotype was unique and contained </span><span>t</span><span>wo</span><span> nonsynonymous substitutions. </span><span>These findings demonstrate that this hybridisation-driven heteroplasmy was maintained across generations for a long time to the extent that the extra mitochondria evolved within the new host.</span></p><p>Funding provided by: Japan Society for the Promotion of Science<br>Crossref Funder Registry ID: https://ror.org/00hhkn466<br>Award Number: KAKENHI 17H01675</p><p>Funding provided by: Japan Society for the Promotion of Science<br>Crossref Funder Registry ID: https://ror.org/00hhkn466<br>Award Number: KAKENHI 22K18370</p><p>Funding provided by: Japan Science and Technology Agency<br>Crossref Funder Registry ID: https://ror.org/00097mb19<br>Award Number: CREST JPMJCR20S2</p&gt

Bloodmeal host identification with inferences to feeding habits of a fish-fed mosquito, Aedes baisasi

Abstract The mosquito, Aedes baisasi, which inhabits brackish mangrove swamps, is known to feed on fish. However, its host assemblage has not been investigated at the species level. We amplified and sequenced the cytochrome oxidase subunit I barcoding regions as well as some other regions from blood-fed females to identify host assemblages in the natural populations from four islands in the Ryukyu Archipelago. Hosts were identified from 230 females. We identified 15 host fish species belonging to eight families and four orders. Contrary to expectations from previous observations, mudskippers were detected from only 3% of blood-engorged females. The dominant host was a four-eyed sleeper, Bostrychus sinensis (Butidae, Gobiiformes), in Iriomote-jima Island (61%), while it was a snake eel, Pisodonophis boro (Ophichthidae, Anguilliformes), in Amami-oshima and Okinawa-jima islands (78% and 79%, respectively). Most of the identified hosts were known as air-breathing or amphibious fishes that inhabit mangroves or lagoons. Our results suggest that A. baisasi females locate the bloodmeal hosts within the mangrove forests and sometimes in the adjacent lagoons and land on the surface of available amphibious or other air-breathing fishes exposed in the air to feed on their blood