The Instigator
Pro (for)
5 Points
The Contender
Con (against)
0 Points

Sea lions are seals

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Voting Style: Open Point System: 7 Point
Started: 7/23/2015 Category: Science
Updated: 1 year ago Status: Post Voting Period
Viewed: 690 times Debate No: 78053
Debate Rounds (3)
Comments (11)
Votes (1)




The topic should be self explanatory.


First round: Acceptance only.

Final round: Rebuttals only. No new arguments.

You flake, you lose.

You troll, you lose.


Hello, Today I accepted this debate.
But I also like saying my definition in my debates. Pro did not write his definition.


Sea lion: a large seal that lives near coasts in the Pacific Ocean.

Seal: any of numerous carnivorous marine mammals (families Phocidae and Otariidae) that live chiefly in cold regions and have limbs modified into webbed flippers adapted primarily to swimming;especially : a fur seal or hair seal as opposed to a sea lion.

Thank you
Debate Round No. 1


Note: The rules for this debate state very clearly that the first round is for acceptance only.


P1 - Any organism of the taxonomic family Phocidae or Otariidae is a seal.
P2 - All sea lions are organisms of the taxonomic family Otariidae.
C1 - Therefore, all sea lions are seals.

This argument is valid. If the premises are true, then the conclusion must be true.

* "P" is an abbreviation for "premise" and "C" is an abbreviation for "conclusion".

Support for P1 -

Support for P1 comes in the form of encyclopedic and dictionary entries for the word "seal". These references are reputable, sufficiently numerous, and are inclusive of the taxonomic families mentioned in P1. The family names have been emphasized.
  • Encyclopedia Britannica [1]
    • any of 32 species of web-footed aquatic mammals that live chiefly in cold seas and whose body shape, round at the middle and tapered at the ends, is adapted to swift and graceful swimming. There are two types of seals: the earless, or true, seals (family Phocidae); and the eared seals (family Otariidae), which comprise the sea lions and fur seals.
  • Oxford Dictionary [2]
    • A fish-eating aquatic mammal with a streamlined body and feet developed as flippers, returning to land to breed or rest. Families Phocidae (the true seals) and Otariidae (the eared seals, including the fur seals and sea lions). The latter have external ear flaps and are able to sit upright, and the males are much larger than the females
  • American Heritage Dictionary [3]
    • Any of various aquatic carnivorous mammals of the families Phocidae and Otariidae, found chiefly in cold regions and having a sleek torpedo-shaped body and limbs that are modified into paddlelike flippers.
  • Collins Dictionary [4]
    • any of two families (Otariidae and Phocidae) of sea carnivores with a doglike head, a torpedo-shaped body, and four webbed feet or flippers: they live in cold or temperate waters and usually eat fish see also eared seal, earless seal

Support for P2 -

Support for P2 comes in the form of encyclopedic and dictionary entries for the term "sea lion." These references are reputable, sufficiently numerous, and demonstrate that sea lion species are of the family Otariidae, which is also referred to as "eared seals." [1][2] "Otariidae" and/or "eared seal" have been emphasized.

  • Encyclopedia Britannica [5]
    • any of five species of eared seals found primarily in Pacific waters. Sea lions are characterized by a coat of short, coarse hair that lacks a distinct undercoat. Except for the California sea lion (Zalophus californianus), males have lion-like manes and constantly roar to defend their harems (hence their name).
  • Oxford Dictionary [6]
    • An eared seal occurring mainly on Pacific coasts, the large male of which has a mane on the neck and shoulders. Five genera and species in the family Otariidae
  • American Heritage Dictionary [7]
    • Any of several large seals of the family Otariidae, having a blunter muzzle and a thinner coat than the fur seals, especially the California sea lion (Zalophus californianus).
  • Collins Dictionary [8]
    • any of several genera of large, eared seals without underfur, usually living in colonies along the Pacific coastline

Sources -

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -



Seals and sea lions are marine mammals called 'pinnipeds' that differ in physical characteristics and adaptations.
seals and sea lions

Sea lions (left) are brown, bark loudly, "walk" on land using their large flippers and have visible ear flaps. Seals have small flippers, wriggle on their bellies on land, and lack visible ear flaps.

Have you ever wondered about the main differences between seals and their "second cousins," the sea lions?

Both seals and sea lions, together with the walrus, are pinnipeds, which means "fin footed" in Latin.

But seals' furry, generally stubby front feet — thinly webbed flippers, actually, with a claw on each small toe — seem petite in comparison to the mostly skin-covered, elongated fore flippers that sea lions possess.

Secondly, sea lions have small flaps for outer ears. The "earless" or "true" seals lack external ears altogether. You have to get very close to see the tiny holes on the sides of a seal’s sleek head.

Third, sea lions are noisy. Seals are quieter, vocalizing via soft grunts.

Fourth, while both species spend time both in and out of the water, seals are better adapted to live in the water than on land. Though their bodies can appear chubby, seals are generally smaller and more aquadynamic than sea lions. At the same time, their hind flippers angle backward and don't rotate. This makes them fast in the water but basic belly crawlers on terra firma.

Sea lions, on the other hand, are able to "walk" on land by rotating their hind flippers forward and underneath their big bodies. This is why they are more likely to be employed in aquaria and marine shows.

Finally, seals are less social than their sea-lion cousins. They spend more time in the water than sea lions do and often lead solitary lives in the wild, coming ashore together only once a year to meet and mate.

Sea lions congregate in gregarious groups called herds or rafts that can reach upwards of 1,500 individuals. It's common for scores of them to haul out together and loll about in the sand, comprising an amorphous pile in the noonday sun.

As part of our summer internship responsibilities, we are required to complete a project that will be useful to the NMLC after we’ve gone back to school. I’m doing a three-part “What’s the Difference?” educational poster/presentation series on seals v. sea lions, dolphins v. porpoises, and toothed whales v. baleen whales. I’m nearing completion of my seal v. sea lion interactive poster, but I can’t use everything that I’ve learned on the poster, so I thought I’d share what I’ve learned in this week’s blog.

Summary of some of the points I'm going to hit in this blog.

What they have in common

Both seals and sea lions are called Pinnipeds, which means “fin-footed.” They are mammals, a group of animals that includes humans that have live young, produce milk, have hair/fur on their bodies, are air breathing, and are “endothermic” or able to control their body temperature. Both types of animals are also semi-aquatic, which means that they spend part of their lives on land, and part of their lives in the ocean. Seals and sea lions are protected by the Marine Mammal Protection Act, which requires that no one harass the animals – which includes getting too close! They also have similar diets, although a few things are different, and they use their specialized whiskers to feel the movement of their prey in the water. They are preyed upon by orcas, polar bears and sharks.

This is a map that shows where seals and sea lions are found throughout the world.


Seals are more adapted for water travel than for land travel because they can’t rotate their back flippers to walk on land, so they move like a caterpillar. The major distinction between seals and sea lions is their lack of external ear flaps.

Photo credit:

Seals also use their back and front flippers differently from sea lions while swimming. Seals use their front flippers to steer, and their back flippers for power. From far away, you might be able to tell a sea lion from a seal because seals frequently have many colors in their fur, and they can’t lift the front part of their body off the ground the way that sea lions can.

Seals reach sexual maturity at 3+ years. Females build up a blubber reserve for the nursing period because many species don’t feed while with their pups. This period can be as short as 4 days, and as long as a few weeks. The mating system in phocids (seals) seems to be more complex than otariids (sea lions). They may have more of a lek-type system in some species, where a male displays to a female or makes underwater vocalizations to attract females, and so she is able to choose her mate. More commonly, however, the dominant male in the area will choose 3-8 females to be a part of his harem. Seals can live to be 14 years old.

Sea Lions

Sea lions include animals referred to as “fur seals.” Fur seals are named misleadingly because they are apart of the Otariid family with sea lions. Sea lions do have external ear flaps – you can see it on the side of the head in both of the pictures below as well as other morphological similarities between sea lions:

California Sea Lion. Photo credit:
Northern fur seal. Photo credit:

They are more adapted for life on land than seals, as they can rotate their back flippers to make it possible for them to walk and run on land. Sea lions can only dive as deep as 450m, but dives further than 200 are uncommon, and they can’t store as much oxygen in their lungs as seals can. Sea lions’ flippers have no hair or claws so that they can more easily grip the surface of rocks, and many of their mating areas are on rocky terrain. The way they use their flippers to swim is different from seals – it’s actually the exact opposite. Sea lions use their long, strong front flippers for power while they swim, and their back flippers for steering. This gives them an advantage when escaping orcas because if the orca were to bite their back flippers, they could still swim quickly to get away, where if a seal had its back flipper bitten, it would no longer have the “power” flippers to keep it moving forward. Sea lions are also usually monochromatic – or they only have one color in their fur, while seals typically have many colors.

The mating system in sea lions is polygynous, which means that there are many females per male. A ratio of 10 females per male is fairly common. The males will defend a patch of land, called a territory, and then all the females on his land are the ones that he mates with. The older and more experienced the male: the better location he has and the more females that want to give birth and nurse their pup on his land. Both otariids and phocids (sea lions and seals) have post partum estrus, or are ready to mate immediately after giving birth. The uterus in females is shaped like a “y”, with one horn holding the full-term fetus and the other preparing to receive the new blastocyst within a few days of birth of the fetus. The females become receptive for mating between 4 and 23 days postpartum. In the Steller sea lion, it has been noted the females that have lost a pup will adopt another. Sea lions are different from seals in that the females will continue eating while lactating, seals fast during this time, and also in that pups stay with the females between 4-12 months, depending on the species. Sea lions also tend to have a little longer lives than seals – they can live to be 15-20 years old.

So that may be more than you ever wanted to know about seals and sea lions! Feel free to come by the center at the end of the summer to see the exhibit I’m designing that will sum up this information and have an interactive component!


Debate Round No. 2


My opponent has merely copy/pasted the contents of two articles. My opponent hasn't presented any argument. However, the implicit claim here is that these 2 sources are inconsistent with and discredit my own sources. They do not.

First, I would like to address the usage of "seal" within my opponent's first source:

It's unclear who authored the article. However, it's a .gov source. So, it is certainly a credible source. The author is using the word "seal" as short hand for "true seal". Within academia, and especially among marine scientists, there is a tendency to do this perhaps for brevity's sake. In response to Con's article, I offer a competing .gov article which uses more appropriate terminology -

This source appropriately refers to true seals. It also corroborates my assertion about the short hand method of referring to true seals when it says that "true seals are also known as earless seals, or simply 'seals'." Sea lions are not true seals - They are eared seals. However, whether or not sea lions are true seals is not the issue here. The issue is whether or not sea lions are seals, and they are. One must not allow the short hand method of referring to true seals lead him to incorrectly conclude that sea lions are not seals.

Con offers another article:

This source is not authoritative. It is from a blog and contains significant errors, e.g.:

"Sea lions include animals referred to as 'fur seals.' "

No, I'm afraid that fur seals are not sea lions. Sea lions are of the subfamily otariinae [ ], while fur seals are of the subfamily arctocephalinae.




I did not write a source of;
Also on your definition of seal, it is a different definition of what I found of sea lion

Sea lion= An eared seal occurring mainly on Pacific coasts, the large male of which has a mane on the neck and shoulders.
  • Five genera and species in the family Otariidae
Also for my reason we...

We urge you to vote for CON!!!
Debate Round No. 3
11 comments have been posted on this debate. Showing 1 through 10 records.
Posted by Death23 1 year ago
I need evidence. I don't got it.
Posted by tejretics 1 year ago

Tell me if you're taking the con side. I'd happily argue as pro.
Posted by brianjustin3709 1 year ago
Are you losing?
Posted by Death23 1 year ago
Sure, sure.
Posted by brianjustin3709 1 year ago
Then that means you got convinced so you should lose!!!
Posted by Death23 1 year ago
I'm not entirely convinced that sea lions are seals. I might take the Con side in the next sea lion debate.
Posted by tejretics 1 year ago

The resolution is a truism. It's obvious that sea lions are seals. That's true by *definition* of "seal". Unfair advantage to Pro.
Posted by Death23 1 year ago
All you did was copy/paste the article. You didn't argue.
Posted by brianjustin3709 1 year ago
Why does he always make the same debate?
Posted by brianjustin3709 1 year ago
1 votes has been placed for this debate.
Vote Placed by tejretics 1 year ago
Agreed with before the debate:--Vote Checkmark0 points
Agreed with after the debate:--Vote Checkmark0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:Vote Checkmark--3 points
Used the most reliable sources:Vote Checkmark--2 points
Total points awarded:50 
Reasons for voting decision: Con basically concedes in the final round, showing that sea lions are a "earless type of seal". This is, basically, a concession. Pro uses credible sources to demonstrate that sea lions are pinnipeds, thus are and ought to be classified as seals, albeit not true seals. As such, it is pretty obvious that Pro wins arguments. Pro wins sources because Con plagiarizes from his true sources -- while he does cite them, he still C/Ps all information instead of typing up his own arguments, which is misuse of sources, and clearly merits losing sources. As such, arguments and sources to Pro.