Identification of the enigmatic Deraniyagala's beaked whale.

It is essential to discover and identify animals in species level in the wild to achieve the collection of baseline data and benefit better understanding and conservation of the rare species. However, this is far from being realized for many beaked whales in the deep sea, including the Deraniyagala's beaked whale (), which is one of the least-known whales with no confirmed live sightings at sea yet all over the world. Here, we provide the first robust field identification of , by integrating DNA sequencing of skin biopsies, acoustic data, and photographs.

Statins Combined with AAV8-TBG-LOX-1 Reduce the Vascular Lipid-driven Inflammatory Response and Inhibit Atherosclerosis.

Objective: Imbalances in liver lipid metabolism and inflammatory reactions driven by oxidized lipid deposition in blood vessels constitute the core of atherosclerosis. Insufficient degradation of cholesterol in the liver promotes oxidative modification of lipid particles and their deposition on the blood vessel wall in the peripheral circulation. The blood vessel wall engulfs and processes oxidized low-density lipoprotein (Ox-LDL) as foreign matter through pattern recognition receptors, ultimately forming lipid-encapsulated plaques.

Interactions between cetaceans and aquatic debris in Chinese waters: A study based on social media data.

Aquatic debris is considered a major threat to cetaceans. China is subject to severe marine plastic waste that may threaten cetaceans. However, the impact of aquatic debris on cetaceans in Chinese waters has remained poorly studied.

Taxonomic composition and functional potentials of gastrointestinal microbiota in 12 wild-stranded cetaceans.

Cetaceans play a crucial role in marine ecosystems; however, research on their gastrointestinal microbiota remains limited due to sampling constraints. In this study, we collected hindgut samples from 12 stranded cetaceans and performed 16S rRNA gene amplicon sequencing to investigate microbial composition and functional potentials. Analysis of ZOTUs profiles revealed that the phyla Firmicutes, Proteobacteria, and Bacteroidetes dominated all hindgut samples.

Genomics of post-bottleneck recovery in the northern elephant seal.

Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence.

Skinny dolphins: Can poor body condition explain population decline in Indo-Pacific humpback dolphins (Sousa chinensis)?

Indo-Pacific humpback dolphins (IPHDs) who form resident populations along the Chinese coastline are facing a wide range of anthropogenic disturbances including intense fishing and some populations have been shown to experience a severe decline. Body condition is thought to be a good indicator of health since it is linked to survival and reproductive success. In order to better understand population trends, we investigated whether the body condition of IPHDs is poorer in populations whose status is alarming than in other populations.

Echolocation clicks of free-ranging Indo-Pacific finless porpoises (Neophocaena phocaenoides) in Hainan waters.

The echolocation clicks of free-ranging Indo-Pacific finless porpoises (IPFPs, Neophocaena phocaenoides) have been rarely studied in the wild. This paper aims at describing the echolocation-click characteristics of IPFPs and examining whether IPFPs adapt their sonar system to the habitats in Hainan waters, China. The echolocation clicks were recorded using a 13 elements star-shaped array of hydrophones.

Inbreeding depression explains killer whale population dynamics.

Understanding the factors that cause endangered populations to either grow or decline is crucial for preserving biodiversity. Conservation efforts often address extrinsic threats, such as environmental degradation and overexploitation, that can limit the recovery of endangered populations. Genetic factors such as inbreeding depression can also affect population dynamics but these effects are rarely measured in the wild and thus often neglected in conservation efforts.

A genome and single-nucleus cerebral cortex transcriptome atlas of the short-finned pilot whale Globicephala macrorhynchus.

Cetaceans (dolphins, whales, and porpoises) have large and anatomically sophisticated brains. To expand our understanding of the cellular makeup of cetacean brains and the similarities and divergence between the brains of cetaceans and terrestrial mammals, we report a short-finned pilot whale (Globicephala macrorhynchus) single-nucleus transcriptome atlas. To achieve this goal, we assembled a chromosome-scale reference genome spanning 2.

Ranging pattern development of a declining delphinid population: A potential cascade effect of vessel activities.

It is generally accepted that vessel activity causes various behavioral responses of cetaceans and undermines individual fitness. Whether or how it can lead to a demographic response of populations remains rarely examined. In the northern Beibu Gulf, China, vessel activities have sharply increased in the past two decades, while abnormal demographic dynamics was recently noted for the resident Indo-Pacific humpback dolphins.

Floating macro-litter pollution in the northern South China Sea.

Marine litter pollution, particularly plastics pollution, is an increasing global concern. While various studies have contributed useful information on this topic, there has been a scarcity of data on floating marine macro-litter (FMML) in poorly monitored areas such as the South China Sea (SCS). This paper describes a large-scale FMML assessment research in the northern SCS.

Gut Microbial Characterization of Melon-Headed Whales () Stranded in China.

Although gut microbes are regarded as a significant component of many mammals and play a very important role, there is a paucity of knowledge around marine mammal gut microbes, which may be due to sampling difficulties. Moreover, to date, there are very few, if any, reports on the gut microbes of melon-headed whales. In this study, we opportunistically collected fecal samples from eight stranded melon-headed whales () in China.

Species diversity and spatiotemporal patterns based on cetacean stranding records in China, 1950-2018.

Stranding data can provide conservation-valuable information on cetaceans over long time and large space, representing a low-cost but useful approach to monitor these indicator species and their inhabiting environments. Here, we established a national dataset by collating all available records of cetacean strandings (CSs) along >30,000-km coastline of China over seven decades. Between 1950 and 2018, a total of 1763 CSs were recorded across 36 cetacean species from eight families.

Blubber fatty acid compositions in different geographic populations of finless porpoise in Chinese waters: implications for thermal adaptation.

The stratification of blubber fatty acids (FAs) is a widely used strategy in marine mammals and can be influenced by many factors, including their diet, environmental temperature, and physiological status. There are 3 distinct finless porpoise species/subspecies in Chinese coastal and inland waters in a wide range from 20°N to 40°N. The biochemical stratification of the blubbers of finless porpoises in different regions may provide valuable information for understanding their environmental adaptations.

Comparative Study of the Gut Microbiota Among Four Different Marine Mammals in an Aquarium.

Despite an increasing appreciation in the importance of host-microbe interactions in ecological and evolutionary processes, information on the gut microbial communities of some marine mammals is still lacking. Moreover, whether diet, environment, or host phylogeny has the greatest impact on microbial community structure is still unknown. To fill part of this knowledge gap, we exploited a natural experiment provided by an aquarium with belugas () affiliated with family Monodontidae, Pacific white-sided dolphins () and common bottlenose dolphin () affiliated with family Delphinidae, and Cape fur seals () affiliated with family Otariidae.

Identification and genome analysis of a novel picornavirus from captive belugas (Delphinapterus leucas) in China.

The discovery of new viruses is important for predicting their potential threats to the health of humans and other animals. A novel picornavirus was identified from oral, throat, and anal swab samples collected from belugas (Delphinapterus leucas), from Dalian Sun Asia Tourism Holding Co., China, between January and December 2018, using a metagenomics approach.

Comparative genomics provides insights into the aquatic adaptations of mammals.

The ancestors of marine mammals once roamed the land and independently committed to an aquatic lifestyle. These macroevolutionary transitions have intrigued scientists for centuries. Here, we generated high-quality genome assemblies of 17 marine mammals (11 cetaceans and six pinnipeds), including eight assemblies at the chromosome level.

Runs of homozygosity in killer whale genomes provide a global record of demographic histories.

Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale (Orcinus orca) demographic history is reflected in genome-wide heterozygosity and ROH length distributions, using a global data set of 26 genomes representative of geographic and ecotypic variation in this species, and two F1 admixed individuals with Pacific-Atlantic parentage.

Numerical-modeling-based investigation of sound transmission and reception in the short-finned pilot whale (Globicephala macrorhynchus).

The sound-transmission, beam-formation, and sound-reception processes of a short-finned pilot whale (Globicephala macrorhynchus) were investigated using computed tomography (CT) scanning and numerical simulation. The results showed that sound propagations in the forehead were modulated by the upper jaw, air components, and soft tissues, which attributed to the beam formation in the external acoustic field. These structures owned different acoustic impedance and formed a multiphasic sound transmission system that can modulate sounds into a beam.