scholarly journals STUDIES ON THE HELMINTH FAUNA OF ALASKA: XLI. OBSERVATIONS ON CESTODES OF THE GENUS DIPLOGONOPORUS LÖNNBERG, 1892 (DIPHYLLOBOTHRIIDAE)

1964 ◽  
Vol 42 (6) ◽  
pp. 1049-1069 ◽  
Author(s):  
Robert L. Rausch
Keyword(s):  
Marine Mammals ◽  
Taxonomic Status ◽  
Domestic Dog ◽  
Steller Sea Lion ◽  
Sea Otter ◽  
Sea Lion ◽  
Marine Habitat ◽  
Von Siebold ◽  
First Time ◽  
Common Parasite

The study of a collection of cestodes assigned to the genus Diplogonoporus Lönnberg, 1892 disclosed but two species, D. balaenopterae Lönnberg, 1892, and D. tetrapterus (von Siebold, 1848) (provis.). These cestodes occur characteristically in marine mammals but occasionally are found in terrestrial hosts; D. balaenopterae is recorded for the first time from the domestic dog, and it is concluded that D. grandis (Blanchard, 1894), from man, is conspecific with D. balaenopterae. The latter species is recorded for the first time from the humpback whale, Megaptera novaeangliae (Borowski), The relatively small D. tetrapterus, a common parasite of the Steller sea lion, Eumetopias jubata (Schreber), is reported for the first time from the sea otter, Enhydra lutris Linnaeus, and from the domestic mink, Mustela vison Schreber. Descriptions of representative specimens are presented, and the taxonomic status of other species assigned to Diplogonoporus is discussed. Although the diplogonadic organization of these cestodes is somewhat variable, it is nevertheless constant and serves to characterize the genus Diplogonoporus. The process of asexual reproduction by means of transverse subdivision of primary segments is described. This ability and the diplogonadic structure of these cestodes are considered to be adaptations that increase the production of eggs and thereby the probability of reproductive success in the marine habitat.

The Abundance and Distribution of the Northern Sea Lion (Eumetopias jubata) on the Coast of British Columbia

1958 ◽  
Vol 15 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Gordon C. Pike ◽  
Brian E. Maxwell
Keyword(s):  
British Columbia ◽  
Local Population ◽  
Sea Otter ◽  
Sea Lion ◽  
Sea Lions ◽  
One Year ◽  
Abundance And Distribution ◽  
Pup Mortality ◽  
First Time ◽  
Sexually Mature

The abundance and distribution of the northern sea lion, Eumetopias jubata, in British Columbia are described chiefly on the basis of a survey conducted during the summer of 1956. Results of surveys and censuses made in the years 1913, 1916, 1938 and 1955 are included for comparison. Most major rookeries and hauling-out sites were visited in 1956. Some which were missed were surveyed by aircraft in 1957.The numbers of sea lions in British Columbia are estimated to be 11,000–12,000 in 1956–57. They have apparently changed little since 1913 and 1916 when the population is estimated less reliably to have been 12,000–13,000. Some changes have occurred in their distribution, mainly as a result of organized destruction of concentrations centred near to fishing areas. Numbers in the Sea Otter Group have been reduced to about one-quarter of their former abundance. Numbers on the Cape St. James rookery, where the population has seldom been molested, have doubled.Present rookeries include: Triangle, Sartine, and Beresford Islands, in the Scott Island group; Kerouard Islands off Cape St. James; and North Danger Rocks. The Virgin and Pearl Rocks in the Sea Otter Group are no longer rookeries. Sartine Island and North Danger Rocks are recorded for the first time as rookeries. The Scott Islands and Kerouard Islands rookeries accommodate approximately 70% of the entire population, and 90% of the pups during the summer breeding season.Destruction of approximately 1,000 sea lions annually, when many of these are pups, is shown to be ineffective in substantially reducing the total population. Where efforts are concentrated in one area such as the Sea Otter Group, however, a local population can be greatly reduced and pupping curtailed or stopped.Pups are born from late May until late June. Soon after giving birth, the cows are serviced by the harem bulls. The harem structure, which averages about 10 cows per harem bull on the rookeries, begins to disintegrate near the end of July when pups take to the water and dominant bulls are replaced by reserve bulls. Some cows, probably not more than 25% at any one time, may forgo the normal annual pregnancy and continue to nurse a pup for more than a year.It is calculated that more than 70% of the sexually mature females in this population are pregnant in any one year. Natural mortality among the pups appears to be slight, but severe storms in some years may cause heavy pup mortality and constitute an important check on population growth.

Present-Day Assemblage of Birds and Mammals in the Islands of Four Mountains, Eastern Aleutians, Alaska

2018 ◽  
Vol 91 (03) ◽  
pp. 1059-1074 ◽  
Author(s):  
Nora A. Rojek ◽  
Jeffrey C. Williams
Keyword(s):  
Marine Mammals ◽  
Red Fox ◽  
Bird Species ◽  
Harbor Seal ◽  
Sea Otter ◽  
Archaeological Record ◽  
Sea Lion ◽  
Mammal Fauna ◽  
Land Mammal ◽  
Insight Into

AbstractWe compiled present-day observations and survey data of the avian and mammal fauna in the Islands of Four Mountains, Alaska, which primarily consist of marine-adapted species, to provide insight into the prehistoric fauna found in the archaeological record. We documented 63 bird species, mainly seabirds (67%). The majority (71%) of the estimated number of breeding birds are ledge nesters, predominately murres, and most (68%) spend the majority of their lives in the offshore environment. We lack good estimates for burrow and crevice nesters, which were impacted by and are still recovering from a period of arctic fox farming in the twentieth century. Marine mammals, predominately Steller sea lion, harbor seal, and sea otter, primarily use accessible land as haul-outs and are found in low numbers compared with the rest of the Aleutians. Red fox, the only land mammal, presently only reside on Chuginadak Island. While the present-day fauna is similar to the fauna recorded in the archaeological record, we found no indication of nesting by ancient murrelets and northern fulmars in the Island of Four Mountains, whereas both species were present in midden sites on Carlisle and Chuginadak Islands, with the possibility of prehistoric breeding colonies on Carlisle Island.

scholarly journals Sea Otter, Enhydra lutris, Sightings off Haida Gwaii / Queen Charlotte Islands, British Columbia, 1972-2002

2004 ◽  
Vol 118 (2) ◽  
pp. 270
Author(s):  
Kimberly Raum-Suryan ◽  
Kenneth Pitcher ◽  
Richard Lamy
Keyword(s):  
British Columbia ◽  
Steller Sea Lion ◽  
Sea Otter ◽  
Eumetopias Jubatus ◽  
Enhydra Lutris ◽  
Haida Gwaii ◽  
Sea Lion ◽  
Sea Otters ◽  
The Past ◽  
Queen Charlotte Islands

On 27 June 2001 we observed and photographed a Sea Otter (Enhydra lutris) adjacent to a Steller Sea Lion (Eumetopias jubatus) haulout near Sgang Gwaay (Anthony Island), Haida Gwaii / Queen Charlotte Islands. This is one of only eight documented sightings of Sea Otters in these waters during the past 30 years. These sightings may represent the beginning of the expansion of Sea Otters to their former range off Haida Gwaii.

Atlas of Marine Mammal Distribution and Abundance in Mexican Waters

2020 ◽  
Author(s):  
Gisela Heckel ◽  
◽  
M.G. Ruiz Mar ◽  
Y. Schramm ◽  
U. Gorter
Keyword(s):  
Marine Mammals ◽  
Sea Otter ◽  
Baleen Whale ◽  
Sea Lion ◽  
Sea Otters ◽  
Cetacean Species ◽  
Sea Lions ◽  
The World ◽  
Toothed Whale ◽  
Mammal Distribution

Marine mammals are a group of charismatic megafauna, capable of awakening fascination in most people, which makes them especially visible when natural resources or ecosystems are exploited, as is the case with the generation of energy using the sea. There are 131 species of marine mammals in the world, including whales, dolphins, sea lions, seals, walruses, sea otters, polar bears, manatees and dugongs. Mexico’s marine environment is megadiverse, with 38 cetacean species (eight mysticeti or baleen whale species, 30 odontoceti or toothed whale species, dolphins and porpoises), four pinnipeds (two seal species and two sea lion species), one sea otter sub-species and one manatee subspecies (

Evidence of a predation event on a tagged Mediterranean spearfish (Tetrapturus belone; Pisces, Istiophoridae), inferred from pop-up satellite tagging data

2020 ◽  
Vol 33 ◽  
pp. 23
Author(s):  
Danilo Malara ◽  
Pietro Battaglia ◽  
Pierpaolo Consoli ◽  
Erika Arcadi ◽  
Simonepietro Canese ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Research Group ◽  
Marine Mammals ◽  
Biodiversity Hotspot ◽  
Pelagic Species ◽  
Archival Tag ◽  
Abiotic Parameters ◽  
Predation Event ◽  
Satellite Tagging ◽  
First Time

The Strait of Messina is located at the centre of the Mediterranean Sea and is considered a biodiversity hotspot and an obligatory seasonal passage for different pelagic species such as sharks, marine mammals, and billfishes. For the first time, in the Strait of Messina, our research group tagged a Mediterranean spearfish (Tetrapturus belone) using a pop-up satellite archival tag (PSAT). The observation of abiotic parameters (depth, light, and temperature) recorded by the PSAT confirmed that the tagged specimen was predated after about nine hours. The tag was then regurgitated 14 days after the tag deployment date. The analysis of collected data seems to indicate that the predator may be an ectothermic shark, most likely the bluntnose sixgill shark (Hexanchus griseus).

scholarly journals Towards a Natural Classification of Hyphodontia Sensu Lato and the Trait Evolution of Basidiocarps within Hymenochaetales (Basidiomycota)

2021 ◽  
Vol 7 (6) ◽  
pp. 478
Author(s):  
Xue-Wei Wang ◽  
Tom W. May ◽  
Shi-Liang Liu ◽  
Li-Wei Zhou
Keyword(s):  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Ancestral State ◽  
Trait Evolution ◽  
Natural Classification ◽  
Multiple Loci ◽  
The Family ◽  
Phylogenetic Perspective ◽  
Taxonomic Framework ◽  
First Time

Hyphodontia sensu lato, belonging to Hymenochaetales, accommodates corticioid wood-inhabiting basidiomycetous fungi with resupinate basidiocarps and diverse hymenophoral characters. Species diversity of Hyphodontia sensu lato has been extensively explored worldwide, but in previous studies the six accepted genera in Hyphodontia sensu lato, viz. Fasciodontia, Hastodontia, Hyphodontia, Kneiffiella, Lyomyces and Xylodon were not all strongly supported from a phylogenetic perspective. Moreover, the relationships among these six genera in Hyphodontia sensu lato and other lineages within Hymenochaetales are not clear. In this study, we performed comprehensive phylogenetic analyses on the basis of multiple loci. For the first time, the independence of each of the six genera receives strong phylogenetic support. The six genera are separated in four clades within Hymenochaetales: Fasciodontia, Lyomyces and Xylodon are accepted as members of a previously known family Schizoporaceae, Kneiffiella and Hyphodontia are, respectively, placed in two monotypic families, viz. a previous name Chaetoporellaceae and a newly introduced name Hyphodontiaceae, and Hastodontia is considered to be a genus with an uncertain taxonomic position at the family rank within Hymenochaetales. The three families emerged between 61.51 and 195.87 million years ago. Compared to other families in the Hymenochaetales, these ages are more or less similar to those of Coltriciaceae, Hymenochaetaceae and Oxyporaceae, but much older than those of the two families Neoantrodiellaceae and Nigrofomitaceae. In regard to species, two, one, three and 10 species are newly described from Hyphodontia, Kneiffiella, Lyomyces and Xylodon, respectively. The taxonomic status of additional 30 species names from these four genera is briefly discussed; an epitype is designated for X. australis. The resupinate habit and poroid hymenophoral configuration were evaluated as the ancestral state of basidiocarps within Hymenochaetales. The resupinate habit mainly remains, while the hymenophoral configuration mainly evolves to the grandinioid-odontioid state and also back to the poroid state at the family level. Generally, a taxonomic framework for Hymenochaetales with an emphasis on members belonging to Hyphodontia sensu lato is constructed, and trait evolution of basidiocarps within Hymenochaetales is revealed accordingly.

Corneal anatomy of marine mammals

1993 ◽  
Vol 71 (11) ◽  
pp. 2282-2290 ◽  
Author(s):  
M. T. Pardue ◽  
J. G. Sivak ◽  
K. M. Kovacs
Keyword(s):  
Marine Mammals ◽  
Equatorial Region ◽  
Balaenoptera Acutorostrata ◽  
Marine Habitat ◽  
Corneal Surface ◽  
Balaenoptera Physalus ◽  
Phoca Groenlandica ◽  
Minke Whales ◽  
Transmission Electron ◽  
Ultrathin Sections

The corneal anatomy of fin whales (Balaenoptera physalus), minke whales (Balaenoptera acutorostrata), harp seals (Phoca groenlandica), ringed seals (Phoca hispida), and bearded seals (Eriganthus barbatus) was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat. One to seven eyes of each species were analyzed: paraffin sections stained with haematoxylin and eosin for light microscopy; and ultrathin sections for transmission electron microscopy. All corneas contain the five typical mammalian layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The corneas of these marine mammals are thicker than human corneas because of a thicker stromal layer. The other layers are thinner than those found in humans, except for the epithelial layer in the bearded seal and the cetaceans where it may provide extra protection for the eye during feeding behaviour. The epithelial cells in all corneas studied have an abundance of tonofilaments, which may strengthen the cells and distribute force across the corneal surface. No special organization of collagen fibrils was found in the stroma that would offer protection from ultraviolet radiation or glare for pinnipeds when on ice. The thickness of the sclera in the cetaceans may serve to hold the inner globe of the eye in an elliptical shape, while the thinning of the sclera in the equatorial region in pinnipeds may flatten the eye in air to reduce aerial myopia.

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