#I GUESS??!?!

[bestanimal]

Round 1 - Phylum Chordata

(Sources - 1, 2, 3, 4)

Chordata is a phylum consisting of bilaterial animals that have, at at least some point in their development, a notochord and a dorsal nerve chord. It consists of the Cephalochordates (lancelets), Tunicates (sea squirts, salps, and larvaceans), and Vertebrates.

Vertebrates replace their notochord with a spine in early development, while tunicates only retain their notochord and dorsal nerve chord during their larval stage. Vertebrates and tunicates are more closely related to each other than they are to lancelets (first image), which are fish-shaped filter-feeders. They typically inhabit the sea floor, burrowing the bottom halves of their bodies into soft substrate. They have gill slits, but these are used for feeding on plankton rather than respiration. They have light-sensing organs, and one frontal eye. They do not have hearts or brains. They have two sexes, though hermaphroditism has been observed, as well as at least one instance of a lab-raised female transforming into a male. They breed by releasing eggs and sperm into the water synchronously. Larvae are asymmetrical, with the mouth and anus on the left side, and the gill slits on the right side.

Most tunicates are also filter-feeders, ranging from the sessile, sponge-like sea quirts (second image) to the planktonic salps. All tunicates start life as free-swimming, tadpole-like larvae with rudimentary brains and light sensors, before they metamorphize into their adult forms. Meanwhile, the larvaceans retain tadpole-like shapes and active swimming all their lives. Salps move by contracting, similarly to jellyfish, straining phytoplankton from the water. They have a complex life cycle, in which one generation of solitary individuals reproduces asexually by producing a chain of tens to hundreds of individuals, which are released from the parent at a small size. The next generation consists of a colony of salps (called blastozooids) remaining attached together while swimming, feeding, and growing. This generation reproduces sexually, first maturing as females and later transforming into males. Older chains of male blastozooids will fertilize the eggs of younger female chains. Growing embryos are called oozooids, and eventually detach from their parent blastozoids, to feed and grow as the next solitary, asexual generation. Meanwhile, some species of sea squirt live as solitary individuals, while others replicate by budding and become colonies of zooids. They are filter feeders with two tubular openings, called siphons, through which they draw in and expel water.

The most simple vertebrates are hagfish, which have a skull but no vertebral column. They are marine predators and scavengers who can defend themselves against larger predators by releasing copious amounts of slime from mucous glands in their skin.

Lampreys have an ambiguous position in the vertebrate tree of life, bearing a complete braincase and rudimentary vertebrae. They spend the majority of their life as filter-feeders. A small handful of species are known to be carnivorous as adults, boring into other fish to consume flesh and/or blood.

Chondrichthyes (“cartilaginous fish”) have skeletons composed mainly of cartilage. They breath through gills but lack opercula (gill coverings). They have internal fertilization and some species lay eggs while others give live birth. Chondrichthyans have tooth-like scales called dermal denticles or placoid scales. These usually provide protection, and in most cases, streamlining. Today, chondrichthyans are represented by sharks, rays, skates, sawfish, and chimaeras. All species are carnivores, though at least one species is omnivorous.

The majority of chordate species are Actinopterygians (“Ray-finned Fishes”). They are so called because of their lightly built fins made of skin webbings supported by thin bony spines. They are the most abundant free-swimming aquatic animals and can be found almost anywhere there is water. They come in a vast majority of sizes, shapes, colors, and behaviors, from the 8 mm (0.3 in) long Paedocypris to the 11 m (36 ft) long Giant Oarfish (Regalecus glesne). In most actinopterygians, males and females exist and reproduce through external fertilization. However, some species utilize sequential hermaphroditism, in which they start life as females and convert to males at some point. In a few species, they start life as males and convert to females. Some species give live birth, and some species self-fertilise. Actinopterygians have feeding strategies ranging from predatory to grazing to filter-feeding.

And lastly, the Sarcopterygians (“Lobe-finned Fishes”), named for the prominent muscular limb buds (lobes) within their fins. They are represented by the coelacanths, lungfish, and tetrapods. The vast majority of the rest of chordate species are tetrapods, a terrestrial clade of sarcopterygians who evolved air-breathing using lungs. They are highly diverse, with a large variety of forms, biological strategies, and ecological roles. Along with arthropods, they are the only other group of animals to have adapted to life in dry environments, and the majority of them live on land.

Chordata is one of the largest phyla of animals when it comes to species and is also one of the oldest phyla, known from as early as the Cambrian explosion.

Propaganda under the cut:

Lancelets naturally express green fluorescent proteins. They may use this green fluorescence to attract plankton towards their mouths.

Mentioned briefly above, the Bonnethead Shark (Sphyrna tiburo), a small species of hammerhead, is the only shark known to be omnivorous. While it feeds on crustaceans, molluscs, and small fish, it also ingests large amounts of seagrass, which has been found to make up around 62% of gut content mass.

The Mangrove Rivulus (Kryptolebias marmoratus), a species of killifish, mostly breeds by self-fertilization and can survive for about two months on land. Males are rare, and can only hatch from eggs kept below 19 °C (66 °F).

The largest chordate is the Blue Whale (Balaenoptera musculus), which can reach a maximum confirmed length of 29.9 m (98 ft) and weigh up to 196 long tons; 219 short tons). While it’s not the longest, it is the largest animal known to have ever existed.

At least one of your favorite animals is probably in this phylum. Most of the animals people keep as pets are in this phylum. We are in this phylum.

I am tired, and there is no way I can write enough propaganda for this poll, so I trust you can supply your own.

[goldensunset]

idk who needs to hear this but if you have been putting something off bc it doesn't need to be done until the end of the month. we are almost done with the teens we are approaching the big numbers (the twenties). that date shall dawn upon you swiftly and without mercy before you know it. psa for everyone except me i got plany off time

[lennyjamin]

spoke deeply to me.

[thenerdestsquirrel]

I saw this and I thought Tumblr might enjoy it

[thisisalovestry]

file -> phrases that are going to shift something in me forever

[pseudophan]

made me think of some of you <3

[coolerhope]

funniest fucking thing

[themathomhouse]

okay but if you ever see a male creative who had a string of great work and then everything else he did was dogshit, go to the "personal life" part of his wikipedia and look at his relationships. you'll either find a major tragedy he didn't recover from (completely understandable) or, more likely, there was a woman in his life doing uncredited shit editing his stuff or contributing generally and she's not there anymore.

I told a friend about this phenomenon in literature and he called me weeks later like, I remembered what you said about women doing uncredited work when tim burton came up. he made a string of bangers then everything else just was nowhere near as good. the timeline matches perfectly to when he was with this german visual artist (lena gieseke). he's done some good work in collaboration, but if things were dug into I suspect we would find she did a lot more than people realise.

so yeah whenever you look around like wow women didn't work in history, or, women aren't auteurs, or, there just aren't as many great female writers - societal reasons for that aside, half the time they absolutely did.

[penumbraphantasm]

ordering a pup cup for my chikorita in lumiose

[ahotknife]

the thing is that childhood doesn't just end when you turn 18 or when you turn 21. it's going to end dozens of times over. your childhood pet will die. actors you loved in movies you watched as a kid will die. your grandparents will die, and then your parents will die. it's going to end dozens and dozens of times and all you can do is let it. all you can do is stand in the middle of the grocery store and stare at freezers full of microwave pizza because you've suddenly been seized by the memory of what it felt like to have a pizza party on the last day of school before summer break. which is another ending in and of itself

[unpeeled-human]

special defense

does this count as anything ???is this art

[tastylemonbread]

a lot of artists dont know how to draw bullets and to be real it bothers me a lot. here's my simple guide on bullets

edit: yes i know i used the wrong terminology by now you can stop saying things. also no that crayon isnt a rocket or caseless or some shit believe me when i say that what i saw was depicting a BULLET. shut up

[goldensunset]

[glitchedsoftware]

people on twitter seemed to like this so sure ill put it here too

[snakebites-and-ink]

Former living weapon absolutely dominating at laser tag