First observation of the courtship behaviour of the giant devil ray Mobula mobular (Myliobatiformes: Mobulidae)

Courtship behaviour of the giant devil ray Mobula mobular is described from northern New Zealand, temperate southwest Pacific Ocean, for the first time. A mating train consisting of a full-term pregnant female and up to four males was observed over a period of 147 minutes. Their behaviour was similar to courtship behaviour observed in other large mobulids. Biting of the female was not observed, possibly due to the female’s use of the surface to prevent males positioning themselves above her. However, the lead male pressed the female’s abdomen and underside each time the female reached or stopped at the surface. The occurrence of pregnant females and mating behaviour off northern North Island confirms breeding occurs in New Zealand waters.     

Global distribution of Risso's dolphin Grampus griseus: a review and critical evaluation

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Apparently contradictory routes in the expansion of two fish species in the Eastern Atlantic

One specimen of the boreal Clupea harengus (Clupeidae) was caught southerly, in the Gulf of Cádiz (southern Spain), whereas a specimen of the subtropical Epinephelus aeneus (Serranidae) was caught northerly, in Galician waters (north-west of Spain). These catches represent a new southernmost record in the eastern Atlantic for C. harengus and the second northernmost for E. aeneus. The co-occurrence of warm and cold affinity fishes in temperate latitudes is unusual, but the existence of anomalies in the temperature of the Atlantic waters could be behind these findings.     

The occurrence and ecology of a marine hydrobiid mudsnail in the southern hemisphere: the Knysna Estuary, South Africa

Earlier published records of the gastropod Hydrobia from the warm temperate Knysna Lagoon on the Indian Ocean coast of South Africa are in error. Nevertheless, an animal hitherto identified as an Assiminea (Assimineidae) or as a Tomichia (Pomatiopsidae) is in fact a Hydrobia s.l., and it does occur intertidally within the Knysna system. The same species also occurs in salt pans in the cool temperate Great Berg Estuary on the Atlantic coast of South Africa. This extends the distribution of confirmed species of the dominant coastal hydrobiid mudsnails of the northern hemisphere into the southern hemisphere. H. knysnaensis (Krauss) occurs patchily at low density near the head of the Knysna Estuary in waters of low salinity. This appears to be a suboptimal habitat, and it is suggested that Hydrobia is restricted to this zone as a result of interference competition from potamidid mudwhelks and ocypodid crabs. The prevalence of potamidids and ocypodids in the tropics and in the temperate southern hemisphere may account for the rareness or absence of hydrobiids in these areas. Unlike its equally intertidal relative, the widespread North Atlantic/Arctic H. ulvae, H. knysnaensis develops directly like other Hydrobia.     

First reports of Pseudo‐nitzschia micropora and P. hasleana (Bacillariaceae) from the Southern Hemisphere: Morphological,molecular and toxicological characterization

Pseudo‐nitzschia H. Peragallo is a marine diatom genus found worldwide in polar, temperate, subtropical and tropical waters. It includes toxigenic representatives that produce domoic acid (DA), a neurotoxin responsible for Amnesic Shellfish Poisoning. In this study we characterized two species of Pseudo‐nitzschia collected from Port Stephens and the Hawkesbury River (south eastern Australia) previously unreported from Australian waters. Clonal isolates were sub‐sampled for (i) light and transmission electron microscopy; (ii) DNA sequencing, based on the nuclear‐encoded partial large subunit ribosomal RNA gene and internal transcribed spacer (ITS)‐ITS1, 5.8S and ITS2 rDNA regions and, (iii) DA production as measured by liquid chromatography‐mass spectrometry. Morphological and molecular data unambiguously revealed the species to be Pseudo‐nitzschia micropora Priisholm, Moestrup & Lundholm (Port Stephens) and Pseudo‐nitzschia hasleana Lundholm (Hawkesbury River). This is the first report of the occurrence of these species from the Southern Hemisphere and the first report of P. micropora in warm‐temperate waters. Cultures of P. micropora, tested for DA production for the first time, proved to be non‐toxic. Similarly, no detectable toxin concentrations were observed for P. hasleana. Species resolution and knowledge on the toxicity of local Pseudo‐nitzschia species has important implications for harmful algal bloom monitoring and management.     

Increased intrusion of warming Atlantic water leads to rapid expansion of temperate phytoplankton in the Arctic

The Arctic Ocean and its surrounding shelf seas are warming much faster than the global average, which potentially opens up new distribution areas for temperate‐origin marine phytoplankton. Using over three decades of continuous satellite observations, we show that increased inflow and temperature of Atlantic waters in the Barents Sea resulted in a striking poleward shift in the distribution of blooms of Emiliania huxleyi, a marine calcifying phytoplankton species. This species' blooms are typically associated with temperate waters and have expanded north to 76°N, five degrees further north of its first bloom occurrence in 1989. E. huxleyi's blooms keep pace with the changing climate of the Barents Sea, namely ocean warming and shifts in the position of the Polar Front, resulting in an exceptionally rapid range shift compared to what is generally detected in the marine realm. We propose that as the Eurasian Basin of the Arctic Ocean further atlantifies and ocean temperatures continue to rise, E. huxleyi and other temperate‐origin phytoplankton could well become resident bloom formers in the Arctic Ocean.     

First report of three benthic dinoflagellates,Gambierdiscus pacificus,G. australes and G. caribaeus (Dinophyceae), from Hainan Island,South China Sea

Species of the marine benthic dinoflagellate genus Gambierdiscus are the principal cause of Ciguatera fish poisoning. This genus has been recorded from tropical to temperate oceans, although Gambierdiscus species have rarely been found in Chinese waters. Our work revealed the morphological and genetic characteristics of three potentially toxic Gambierdiscus species observed in the temperate to subtropical waters of China. The fine thecal morphology was determined based on light microscopy and scanning electron microscopy analyses, and these species were also characterized by sequencing the D1–D3 and D8–D10 regions of the LSU rDNA. The morphological and genetic data indicated that these three Gambierdiscus species were G. pacificus, G. australes and G. caribaeus. This work provides the first report of these species in Chinese waters, which increases the known species distribution of this genus.     

Northernmost record of a whale shark Rhincodon typus from the Sea of Okhotsk

The whale shark Rhincodon typus is the world's largest fish and it occurs in tropical, subtropical and warm temperate waters. Here, the northernmost record of R. typus is reported, when it was found in the Sea of Okhotsk for the first time. This occurrence can be explained by the unusually high sea surface temperature during the summer of 2012.     

New and historical records of the ocean sunfish Mola mola in Icelandic waters

The ocean sunfish Mola mola is considered to be globally distributed in both temperate and tropical waters, but there are many gaps in the knowledge of this species' distribution. A total of 31 records of M. mola from Icelandic waters, dating from 1845 to 2014, are presented and georeferenced. An increase in the number of records at the beginning of this century and particularly in 2012, is suggested to be a consequence of both an increase in ocean temperature on the Icelandic shelf and changes in large scale temperature variations in the North Atlantic Ocean.     

The first record of Sirenia (Mammalia) from the early Oligocene of the Paratethys

Abstract

Sirenians have been extensively recorded from the Mediterranean and west European localities but there are only few finds to the east of it, from the area covered by the Paratethys. For the early Oligocene, to our knowledge, there are no published records of sirenians from inner seas of the Old World. Here we report a specimen of Dugongidae indet., consisting of two partial vertebrae and 12 fragments of ribs, collected in a manganese ore mine in Ukraine and dated as the earliest Oligocene (33–32 Ma). The specimens, as preserved, did not differ in morphology and size from ‘Halitherium schinzii’ and therefore can belong to Kaupitherium, at present the single early Oligocene genus recorded from Europe. However, its vertebral and rib anatomy is not specific for Kaupitherium, so we identify it only by family level. The marks of scavenging on a rib possibly are due to gastropod or bivalve mollusks. The sea, as suggested from biotic data, had a temperate or subtropical climate, relatively cold waters and high diversity of pelagic and deep-water habitats. Thus, the onset of the Oligocene was a period when sirenians could enter temperate inner Eurasian waters, a marginal area in their worldwide dispersal.     

Not all fish are equal: functional biodiversity of cartilaginous fishes (Elasmobranchii and Holocephali) in Chile

A review of the primary literature on the cartilaginous fishes (sharks, skates, rays and chimaeras), together with new information suggests that 106 species occur in Chilean waters, comprising 58 sharks, 30 skates, 13 rays and five chimaeras. The presence of 93 species was confirmed, although 30 species were encountered rarely, through validated catch records and sightings made in artisanal and commercial fisheries and on specific research cruises. Overall, only 63 species appear to have a range distribution that normally includes Chilean waters. Actual reliable records of occurrence are lacking for 13 species. Chile has a cartilaginous fish fauna that is relatively impoverished compared with the global species inventory, but conservative compared with countries in South America with warm‐temperate waters. The region of highest species richness occurs in the mid‐Chilean latitudes of c. 30–40° S. This region represents a transition zone with a mix of species related to both the warm‐temperate Peruvian province to the north and cold‐temperate Magellan province to the south. This study provides clarification of species occurrence and the functional biodiversity of Chile's cartilaginous fish fauna.     

Genomics for conservation: a case study of behavioral genes in the Tasmanian devil

The increased availability of genomic resources for many species has expanded perspectives on problems in conservation by helping to design management strategies for threatened species. Tasmanian devils (Sarcophilus harrisii) are an iconic and endangered marsupial with an intensively managed breeding program aimed at preventing extinction in the wild caused by devil facial tumour disease. Between 2015 and 2017, 85 devils from this program were released to three sites in Tasmania to support wild populations. Of these, 26 were known to have been killed by vehicles shortly after release. A previous analysis indicated that increased generations in captivity was a positive predictor of vehicle strike, with possible behavioural change hypothesised. Here we use 39 resequenced devil genomes to characterise diversity at 35 behaviour-associated genes, which contained 826 single nucleotide polymorphisms (24 were non-synonymous). We tested for a predictor of survival by examining three genes (AVPR1B, OXT and SLC6A4) in 62 released devils with known fates (survived, N?=?39; died, N?=?23), and genome-wide associations via reduced-representation sequencing (1727 single nucleotide polymorphisms [SNPs]), in 55 devils with known fates (survived, N?=?38; died, N?=?17). Overall, there was little evidence of an association between genetic profile and probability of being struck by a vehicle. Despite previous evidence of low genetic diversity in devils, the 35 behaviour-associated genes contained variation that may influence their functions. Our dataset can be used for future research into devil behavioural ecology, and adds to the increasing body of research applying genomics to conservation problems.

     

Three species of Pycnadenoides Yamaguti, 1938 (Digenea: Opecoelidae), including two new species from temperate marine fishes of Australia

Pycnadenoides pagrosomi Yamaguti, 1938 and P. reversati n. sp. from Pagrus auratus (Sparidae) and P. invenustus n. sp. from Nemadactylus valenciennesi (Cheilodactylidae) are described from the temperate marine waters off south-west Western Australia and south-east Queensland. The difference in the anterior extent of the vitelline follicles observed in P. reversati n. sp. recovered from off south-east Queensland waters and the material from off Western Australia is discussed. P. reversati n. sp. is distinguished from P. pagrosomi mainly in the position of the genital pore and in the arrangement of the testes, and from P. invenustus n. sp. in the posterior extent of the cirrus-sac. P. reversati belongs to the group of species with a short cirrus-sac and P. invenustus to the group with the cirrus-sac reaching into the anterior hindbody.     

First record of a rare pelagic octopod,Ocythoe tuberculata (Cephalopoda: Ocythoidae), in Korea

The family Ocythoidae is found throughout the temperate and subtropical waters of the world’s ocean and contains a single species, Ocythoe tuberculata. Recently, a single female specimen of the rare pelagic species O. tuberculata was collected off Uljin in the East Sea/Sea of Japan of Korea by squid jigging for the first time. The appearance of this species could be considered as evidence of the changes in species distribution of sea surface. However, further studies are required to investigate whether this phenomenon is temporary or continuous.     

Comparisons between the biology of two co-occurring species of whiting (Sillaginidae) in a large marine embayment

Synopsis We compare the biology of the tropical species Sillago analis and the temperate species Sillago schomburgkii in Shark Bay, a large subtropical marine embayment on the west coast of Australia. This environment constitutes approximately the southernmost and northernmost limits of the distributions of these two species, respectively. The annuli visible in sectioned otoliths of S. analis and S. schomburgkii form annually. Their numbers were thus used to age the individuals of these two species, which are morphologically very similar and live in the same habitats. Although the growth rates of S. analis and S. schomburgkii are very similar until maturity is attained, they subsequently diverge, with S. schomburgkii investing relatively more energy into somatic growth. The maximum total lengths and ages of both the females (320 mm, 6 years) and males (283 mm, 8 years) of S. analis were not as great as those of the females (383 mm, 9 years) and males (302 mm, 9 years) of S. schomburgkii. In Shark Bay, S. schomburgkii spawns earlier and longer than S. analis, i.e. August–December vs. January–March, which would result in the juveniles of these two species recruiting into nursery areas at different times. In addition, S. schomburgkii spawns earlier and for longer in Shark Bay than in temperate marine waters 800 km further south, presumably reflecting the fact that, in that subtropical embayment, water temperatures over which this species typically spawns are attained earlier and last for longer. However, although environmental conditions in Shark Bay and those temperate marine waters differ markedly, the growth of the corresponding sexes of S. schomburgkii in these two water bodies is similar.     

Vocal activity of tropical dolphins is inhibited by the presence of killer whales,Orcinus orca

Research has suggested killer whale (Orcinus orca) predation may affect cetacean vocal behavior; however, few data exist to test this hypothesis. Data collected during 40,976 km of visual and acoustic shipboard surveys in the tropical Pacific Ocean, including 1,232 detections of 13 species, were examined to determine if changes in dolphin vocal activity could be attributed to the presence of killer whales. Generalized linear models and Random Forest analyses were used to test the hypothesis that dolphin vocal activity was related to the distance and time to the nearest killer whale sighting. Both results show that dolphin vocalizations were inversely correlated with the temporal proximity of killer whales (P < 0.05). Despite the relative rarity of killer whales in the tropics, they appear to influence vocal behavior of nearby dolphin schools. This disruption in communication may not significantly impact interactions necessary for survival in tropical waters where killer whale density is low. However, in temperate climates, where increased productivity supports a greater abundance of killer whales, this interruption in communication may have a greater impact. The lower incidence of whistling dolphins in temperate waters may be related to the greater abundance of killer whales in these areas.     

Multi-locus phylogeny of dolphins in the subfamily Lissodelphininae: character synergy improves phylogenetic resolution

Background  

Dolphins of the genus Lagenorhynchus are anti-tropically distributed in temperate to cool waters. Phylogenetic analyses of cytochrome b sequences have suggested that the genus is polyphyletic; however, many relationships were poorly resolved. In this study, we present a combined-analysis phylogenetic hypothesis for Lagenorhynchus and members of the subfamily Lissodelphininae, which is derived from two nuclear and two mitochondrial data sets and the addition of 34 individuals representing 9 species. In addition, we characterize with parsimony and Bayesian analyses the phylogenetic utility and interaction of characters with statistical measures, including the utility of highly consistent (non-homoplasious) characters as a conservative measure of phylogenetic robustness. We also explore the effects of removing sources of character conflict on phylogenetic resolution.     

The new Arctic side-gilled sea slug genus <Emphasis Type="Italic">Boreoberthella</Emphasis> (Gastropoda,Opisthobranchia): Pleurobranchoidean systematics and evolution revisited

Most of the ca. 100 known pleurobranchoid side gilled sea slug species are confined to temperate and warm coastal waters worldwide. Exceptions were five enigmatic Antarctic and southern deep sea species. Herein the first Arctic deep water pleurobranchid, Boreoberthella augusta gen. et spec. nov., is anatomically described. To reveal the origin, relationships and phylogeography of Boreoberthella, a cladistic analysis of 24 pleurobranchoid taxa representing all genera and traditional higher groups was prepared. The morphological data set includes 72 characters; many of them, such as details of the copulatory apparatus, were explored for the first time. The monophyly of both Pleurobranchoidea and Pleurobranchaeidae is confirmed. In contrast to an earlier study, the southern Ocean deep-water species Tomthompsonia antarctica results as basal offshoot of the monophyletic though poorly supported Pleurobranchidae which show a secondary, internal shell. The traditional genus Berthella with worldwide temperate and tropical members may represent an evolutionary grade rather than a clade. The monotypic genera Parabathyberthella and Polictenidia are synonymized with Bathyberthella according to taxonomic and phylogenetic evidence. The basal pleurobranchaeid genus Pleurobranchella, together with Tomthompsonia, Bathyberthella, and Boreoberthella are discussed as potential relics of a cold-water related early nudipleuran radiation in Antarctica, with subsequent dispersal through the depths of the world oceans. The ancestor of Pleurobranchus species, the closest relatives of Boreoberthella, colonized coastal and warmer waters and radiated there.     

THE INVASIVE GENUS ASPARAGOPSIS (BONNEMAISONIACEAE,RHODOPHYTA): MOLECULAR SYSTEMATICS,MORPHOLOGY, AND ECOPHYSIOLOGY OF FALKENBERGIA ISOLATES1

The genus Asparagopsis was studied using 25 Falkenbergia tetrasporophyte strains collected worldwide. Plastid (cp) DNA RFLP revealed three groups of isolates, which differed in their small subunit rRNA gene sequences, temperature responses, and tetrasporophytic morphology (cell sizes). Strains from Australia, Chile, San Diego, and Atlantic and Mediterranean Europe were identifiable as A. armata Harvey, the gametophyte of which has distinctive barbed spines. This species is believed to be endemic to cold‐temperate waters of Australia and New Zealand and was introduced into Europe in the 1920s. All isolates showed identical cpDNA RFLPs, consistent with a recent introduction from Australia. Asparagopsis taxiformis (Delile) Trevisan, the type and only other recognized species, which lacks spines, is cosmopolitan in warm‐temperate to tropical waters. Two clades differed morphologically and ecophysiologically and in the future could be recognized as sibling species or subspecies. A Pacific/Italian clade had 4–8° C lower survival minima and included a genetically distinct apomictic isolate from Western Australia that corresponded to the form of A. taxiformis originally described as A. sanfordiana Harvey. The second clade, from the Caribbean and the Canaries, is stenothermal (subtropical to tropical) with some ecotypic variation. The genus Asparagopsis consists of two or possibly three species, but a definitive taxonomic treatment of the two A. taxiformis clades requires study of field‐collected gametophytes.     

Larval development of bigmouth manefish Caristius macropus (Perciformes: Caristiidae) from the western North Pacific

Larvae of bigmouth manefish Caristius macropus are described and illustrated on the basis of seven specimens (4.2–10.5 mm in body length) from the Kuroshio waters (0–60 m depth) and the transition waters (surface) between the Kuroshio and Oyashio fronts of the western North Pacific. The present larvae of C. macropus are distinguished from those of Paracaristius maderensis that inhabit the North Pacific by having 39–40 myomeres, 34 dorsal-fin rays, and 22 anal-fin rays. The present study, along with previous studies of the early life stages of caristiids, shows that larvae of the family may be defined by the following characters: body elongate in preflexion stage but becoming deep bodied and hatchet shaped after notochord flexion; anus located near vertical through base of pectoral fin; head large, without spination or serration; a distinct vertical band on the posterior tail throughout the larval stages, and two bands gradually appearing on the tail and trunk during the flexion and postflexion stages; and melanophores present around the notochord tip by the flexion stage. Adult C. macropus are found in the subarctic and temperate waters of the North Pacific; however, the present study and other occurrences of early life stages of the species probably indicate that C. macropus may spawn over a wide area in the North Pacific.