Dolphins - Science topic
Mammals of the families Delphinidae (ocean dolphins), Iniidae, Lipotidae, Pontoporiidae, and Platanistidae (all river dolphins). Among the most well-known species are the bottle-nosed dolphin and the killer whale (a dolphin). The common name dolphin is applied to small cetaceans having a beaklike snout and a slender, streamlined body, whereas porpoises are small cetaceans with a blunt snout and rather stocky body. (From Walker's Mammals of the World, 5th ed, pp978-9)
Questions related to Dolphins
Hello, I run Kruskal-Wallis to test if there are statistical significant differences between the occurrence of dolphin sightings for two fishing season. There is not. I have to explain this graph, but I don't know how should be the correct caption.
I am new to the world of Artemia and I am running into some troubles I hope someone might be able to help with :) I grow A. franciscana nauplii in the lab (starting salinity : 45g.l) in glass tanks, at 23 degrees C and feed them with dry spirulina (1g diluted in 200 ml of RO water, and then I dispense ~1-2 drops of this solution per individual). I use Red Sea Salt diluted in RO water but I do not proceeded at any water change between the moment they are naupli instar 1 and to the moment they form pairs. I incrementally increase the salinity by 5% every other day when the larvae are 10 days old to reach a salinity of 90g/l. I noticed from the literature that my Artemia are growing slowly: ~4weeks to reach adulthood. Not sure why, could be density, but this is not my biggest issue. See below...
When pairs form in the tanks, I isolate them into individual containers (so far, I have tried plastic cups, plastic drosophila vials, and glass beakers) in a volume of 150 ml of freshly made 90g/l salt water, give the pairs a drop of food. Within 48-72 hours, all of these isolated pairs die whereas those in the main tank, at the same salinity, with the same diet, exposed to the same photoperiod regime and the same air, are just fine. Does any one have any idea as to why the isolated pairs die when the others are fine?
Worth noting: in the isolated pairs, males develop very quickly some black spots on their legs are claspers. I do not know what this is, I can't really find any info on this potential (?) issue, but suggestions on what that might be are welcome :)
Many thanks in advance for your help and your time
These pictures were taken in French Polynesia by a talented friend with whom I disagree on the species' identification.
I won't mention what I think it is, but I would gladly receive your opinions. He says the dark patches were enhanced by the photo.
Thank you very much in advance
I have been told that with an average dorsal fin height measurement I can then estimate the space between tooth rakes. I am in the process of retrieving this piece of information from some colleagues, but I am then wondering how to calculate the actual space with only a mean DH measurement? Any suggestion? Many thanks
The bottlenose dolphin (Tursiops truncatus) in the Alboran Sea is known to feed on the catch retained in gillnets and also in small pelagic purse seines. At the same time an invasive alga, Rugulopteris okamurae, has recently appeared in Alboran, which is occupying the entire coastline and clogging the fishing gear. We do not know how the presence of the algae will affect the abundance and distribution of the dolphins, nor do we know whether the bottlenose dolphins left the waters of Alboran or suffered feeding problems as the fishing nets were less accessible.
Is there any other marine area where something similar is happening? Are there any areas where the appearance of invasive algae has negatively affected dolphin populations?
I am building four seasonal habitat models for dolphins using sightings from boat surveys. For training presences (count) I have: dry season = 53, pre-monsoon = 10, monsoon = 48, and post-monsoon = 15 after removing multiple occurrences per grid cell.
To reduce sample selection bias, I am using the SWD ("samples with data") option in Maxent. This allows me to draw the environmental samples from a distribution of locations with the same selection bias as the occurrence data. I will draw environmental samples from randomly chosen boat track vessel points.
Given the number of dolphin sightings available for each season, what is the recommended sample size for background data (no sightings) to build a model for each of the four seasons using the SWD option? I am thinking of including at least one sample point per grid cell that the survey boat traveled through during each season. Thanks for sharing any suggestions.
Hi segmentation experts,
I want to segment and measure the volume of the masseter muscles from CBCT data. I read Gupta et al. (2016) but am unsure how to do so in Dolphin. I read Pan et al. (2020) and can get some results from ITK-SNAP, however the segmentation is quite rough and if I make it smooth it may easily leak into adjacent muscles (see attached screenshot). Also, I do not have access to the AI algorithm used by Pan et al. (2020).
Your advice and help on ITK-SNAP is much appreciated. Thank you!
Animal self-awareness usually be tested with the classical mirror test ( The mirror test is a measure of self-awareness developed by Gordon Gallup Jr in 1970, and animals which have passed the mirror test are common chimpanzees, bonobos, orangutans, dolphins, elephants, humans and possibly pigeons. ). However, the mirror test may not appropriate for test the self-awareness for invertebrates , especially arthropods, as visual signals usually be not crucial for these creatures, or they may not care about some marked points on their body etc. Is there any possible methods to test the self-awareness of these organisms?
Recent studies show that sand mining is seriously affecting our environment, more than fossil fuel use. Some species are facing extinction as a result of sand mining on the ocean floor; the Yangtze River dolphin is already extinct. Traditionally, sand is used to manufacture glass. Today, huge skyscrapers erected in two years outnumber those constructed in the U.S. in a 20-year period due to accelerated rates of concrete-making in more populous and / or wealthier nations.
Sand, like coal and oil, is exhaustible, and a lot more plentiful.
In your opinion, is inevitable loss of all of the sand on Earth harmful?
If you think that because of their well researched communication (people try now to create a dolphin dictionary), their individual and emotional behaviour, their social skills and intelligence, their sense of self awareness, they (all kinds of whales and dolphins) are second most intelligent species on earth, ..-- so can we go on kill them?
How about international laws to forbid this?
Should You agree and want to support, so give a positive vote to:
I was wondering if anyone could give some suggestions about:1) methods to use for mapping distribution of dolphins (and modelling using benthic habitat data) when there were no track effort recorded. The only information is a vague location (possibly GPS locations but not as accurate as today). Note, I'm referencing to data collected in the 1990s; 2) whether there is a way to compare those data with other collected in the last decade (i.e., track effort available; accurate location)...
For a project, I have been researching the common ancestor of the short beaked dolphin and the domestic pig. Any other evidence of their relation (homologous structures or nucleotide sequences) is also much appreciated.
I wish to determine pairwise relatedness and eventually reconstruct pedigrees for a population of dolphins using high-density microsatellites (>2000 loci/individual). However, most genome-wide estimators of IBD are optimized for SNPs. Is anyone aware of a program that can compute IBD/kinship coefficients from multiallelic genome sequence data? Alternately, does anyone have experience entering microsats into PLINK or KING?
Ideally I would like to be able to use a program like PRIMUS or CLAPPER to reconstruct pedigrees.
Two species of coastal dolphins, whose groups of females-calves are annual residents and with a similar habitat use that leads them to interact in almost 75% of the time they are sighted, can establish stable social ties despite being different species?
I have received project reports Lazar et al. 2017 and Pabi et al. 2014
evaluating recent stocks of small pelagics (Sardinella aurita, S. maderensis, Engraulis encrasicaulis, Scomber colias) off Ghana, but I search published information on long-term seasonal presence and reproductive biology, as to correctly interprete dolphin (predator) presence. Anyone can suggest/provide papers? Thanks.
Some animals like whales, dolphins, bats, and ants can produce ultra or infra sounds. Can we use these waves to cure diseases like cancer?
The question relates to a steel hollow pile that is driven into a (sandy) soil. The pile is meant to function as a dolphin pile. From current literature I can find a structural damping coefficient for steel structures of c=0,007.
For this research however I'm looking for the (positive) effect on the dampingcoefficient c or dampingratio (zeta) that is caused by the surrounding soil.
You may consider to add these papers to your reference list. They document the presence and epidemiology of lobomycosis-like disease in common bottlenose dolphins from the Gulf of Guayaquil.
Van Bressem MF, Van Waerebeek K, Reyes JC, Felix F and
others (2007) A preliminary overview of skin and skeletal
diseases and traumata in small cetaceans from South
American waters. Lat Am J Aquat Mamm 6: 7−42
Van Bressem MF, Simões-Lopes PC, Félix F, Kiszka JJ and others (2015) Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa. Dis Aquat Org 117:59-75. https://doi.org/10.3354/dao02932
Before posting this question, I'd like to state that the following must not be regarded by any means to a discussion on catching marine mammals in EU seas.
Why are marine mammals (namely very common species of dolphins and pinnipeds) strictly protected in EU waters while Bluefin tunas, rare and collapsing as they are, are still apparently overfished mainly in the Mediterranean's W basin? Do you think that this has something to do with the "cuteness" of marine mammals and the fact that Thunnus thynnus is "just a fish"?
Many thanks for your contributions.
Flower, W.H. (1870) Description of the skeleton of the Chinese white dolphin (Delphinus sinensis). Transactions of the Zoological Society of London 7: 151-160.
Zoological Society of London (ZSL) who formerly published Trans. (now J. Zoology), through Wiley Online Library charges USD 38.0 for this 147 yr old paper on dolphin anatomy, all the while brandishing the motto "Let's Work for Wildlife", no less. ZSL should be ashamed: many genuine Workers for Wildlife are volunteers in developing countries and cannot afford paying for 2 centuries-old scientific papers. Author W.H. Flower would surely turn in his grave if he knew.
I am working on the interaction of Irrawaddy Dolphins and fishing gears in a bay in the Philippines. Too much number and kinds of gears sometime accidentally entangle and kill dolphins. I need suggestions from experience on management approach that would keep dolphins from entangling in nets and ropes at the same time will not greatly affect the source of income of the fishers?
First photo is electron micrograph of dolphin stomach infected with a digenean parasite, and the other two are electron micrographs of intestine of Sprague-Dawley rat experimentally infected with Anisakis spp.
I was told that females of Atlantic Spotted Dolphin tend to get more spots after going through pregnancy, due to hormonal variation, in the same way some women notice changes in pigmentation during pregnancy.
Any opinions on this?
I´ve been looking for papers regarding this topic but found none myself...
I would like to know if any of you have a good experience with the pop-up tags from Desert Star, particularly GEO 3D. I intend to use them with dolphinfish. Thanks
how the meaning of these images?
This images is result from processing with Software Matlab with Syntax FFT to Specgram
Thank You For Attention
Whether the Software Raven pro 64 bit 1.5 (Bioacoustics Cornell Lab of Ornithology USA) is able to analyze the spectrum of dolphins with specific?
logarithms, frequency range, and the range of intensity ??
Thank You ,..
I'm looking for references to vocalizations of Stenella attenuata. If anyone has any references, please let me know!
As for whistles we have the visual inspection method and others quantitative ones to classify them in sub-types, I am looking for any already published method to do the same with burst-pulse vocalizations in dolphins.
I need to find a program that can track the movements of a bottlenose dolphin in Belize. The video was taken from drone from a moving boat. The program would need to have the capability to track the movements of a video that is not fixed on one location such as a tank. The program would need to be able to follow the movement of the animal in the video, move with the video, and create a downloadable track.
About 20 percent of the bottlenose dolphin's body weight is blubber, Since one of its function is to insulate the body in an aquatic environment, I was wondering if anyone has studied the correlation between blubber tickness and water temperature ? Or is their any study on body shape variation vs water temperature?
I have run across a number of anecdotes of this growth affecting some Tursiops aduncus bottlenose in/around the Broadwater estuary on the Gold Coast, Australia, around 10-15 years ago (2000-2005). No-one has been able to provide me with pictures. The growth protruding from their mouth made it impossible to accept food from boaters who tried to provision them. Not surprisingly, they disappeared fairly quickly.
I've found one passing reference to a similar condition but the study simply made mention of a male, on its own, with the growth, and didn't study or investigate further.
I'd be interested of any other sightings of such a condition, any thoughts on what it might be, or any photos.
I am extracting hormones from sea lion lipids and most of my samples have solids precipitating out, which I haven't seen with dolphins. I'm wondering if there is some property of sea lion fat that would cause this? I haven't come across a paper that explains what I am seeing. Thanks!
I have attached the picture of the humpback dolphin taken past November in the Persian Gulf as part of my research there. I am not really sure if this type of mark could be caused by a propeller as it looks like that there are marks on the body. Has someone observed something similar in other dolphins?
I have attached the picture of the humpback dolphin taken past November in the Persian Gulf as part of my research there. I am not really sure if this type of mark could be caused by a entanglement in a gillnet. Has someone observed something similar in other cetaceans?
My Sp1K since their purchase at passage 8 have been very slow in growing, but now they stopped. We used all medium and reagents as raccomended, they are Mycoplasma free, but they are stopped from about 10 days, now they are at passage 13 is senescence possible already in this cell line?
I observed horseflies (Tabaniidae) biting bottlenose dolphins (Tursiops truncatus) in a caribbean mangrove area. I can't find reports on bloodsucking insects predating on completely aquatic mammals (dolphins, whales, manatees). Does anyone have any information/paper about the subject?
Am devising a campaign for project, any extra info would be greatly appreciated, especially surrounding their dietary requirements/habits and techniques used to assess this. Thank you
I am trying to categorize burst-pulse sounds of dolphins within a data set, and am having trouble figuring out how to determine the pulse repetition rate of a sound. Raven (Cornell software) does not seem to have any instructions on how to do it in their software, but is this something another software can do? Can you count the number of pulses visually? Do I need a code, for example in Matlab? Any help would be greatly appreciated!
Does anyone have photos of malformations on the fluke of bottlenose dolphins and is interested in discussing it? Last year there was a stranding of a young bottlenose with a malformation on its fluke. Since then I have been trying to gather information and references that might help in order to prepare a short note (hopefully!). Does anyone want to share information and be involved in the publication?