#DAILYWORM
Daily worm is a series of little digitally illustrated factoids about worms and other super interesting and cool invertebrates. Updated every other day. Both this and #dailypeen are posted on my insta.
#DAILYPEEN
Daily peen is a series of little digitally illustrated factoids about animal reproduction (originally very penis-centric, hence the name). Updated every other day.
I’ve gotten conflicting info on whether or not the males desiccate only leaving their gonads behind or whether they actually thrive better than free-living males. 
This is the grossest penis I have yet drawn. 
I found conflicting diagrams, both from published books, on whether the fertilizing clasper is anterior or posterior to the spiny knob clasper. It might vary between species. 
Most flatworms are a little more chill about mating. 
I recommend watching some youtube videos about this, because those penises are out there, waving around like giant snakes. 
Shark sex is BRUTAL. Also, now you know sharks, skates, and rays have external genitalia, you can go to an aquarium and correct people whenever they misgender the fish. It’s a lot of fun! Probably why no one ever wants to go to an aquarium with me twice, because they can’t imagine having so much fun a second time. 
What I want to know is if this makes them swim around in circles. 
I’m guessing they pheromones to find their mates, but I like to imagine a large rock covered in barnacles, little penises emerging from all of them, feeling around like long thin little fingers. 
There is a LOT of debate about why genital structures are so varied among species. SO MUCH DRAMA. 
Not saying human copulation is short, but… there’s no bone in your boner, friend. 
SO MANY SPINES! 
There is an amazing video of this- the link is in the references. It just pops out like a jack-in-the-box! 
They do have long proboscises, tho. 
This is my favorite penis fact, by far. Such a cute little slug mucus cuddle. 
I did my best to draw this honey bee penis, but honestly I have no idea how well I did. 
Echidnas are like hedgehogs if they were marsupials instead of… whatever hedgehogs are. 
I am not clear on why the penises corkscrew in the first place tho. Maybe it helps them evert (inflate) faster? 
These little slugs are TINY. Like just a few mm long. 
This is a series of little illustrated factoids about animal reproduction, posted daily. I’d love to hear your suggestions/ feedback. I also post these on my insta.
NEW! #dailypeen merch! Just in time for the holidays- who doesn’t want apparel/ household goods/ stationary with animal dicks on them? I know I do. (I’m honestly most excited about the socks.)
Send some unsolicited dick pics 
PENIS WORM SOCKS, GUYS! 
MOR PENIS SOCKS- 6 DIFFERENT VERTEBRATE PENISES ON YOUR FEET!!! 
Penis fact mugs will keep you warm during the long winter 
JUST THE TIPS is what I should have called this- oh wait I can go back and change it, brb 
Wear a penis worm on your collar 
Or you could just be totally covered in penises 
The perfect place to lay your head. 
Penises on your legs!
References, # DAILYPEEN:
Priaprim: Shibukawa, K., Tran, D.D. and Tran, L.X., 2012. Phallostethus cuulong, a new species of priapiumfish (Actinopterygii: Atheriniformes: Phallostethidae) from the Vietnamese Mekong. Zootaxa, 3363(1), pp.45-51.
Sea slug: Anthes, N. and Michiels, N.K., 2007. Precopulatory stabbing, hypodermic injections and unilateral copulations in a hermaphroditic sea slug. Biology Letters, 3(2), pp.121-124.
Duck: Brennan, P.L., Clark, C.J. and Prum, R.O., 2010. Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia. Proceedings of the Royal Society B: Biological Sciences, 277(1686), pp.1309-1314.
Echidna: Johnston, S.D., Smith, B., Pyne, M., Stenzel, D. and Holt, W.V., 2007. One-sided ejaculation of echidna sperm bundles. The American Naturalist, 170(6), pp.E162-E164.
Leopard slug: Davison, Angus, 2019. Leopard slugs mate in the most beautifully bizarre way – and nobody knows why. The Conversation. https://theconversation.com/leopard-slugs-mate-in-the-most-beautifully-bizarre-way-and-nobody-knows-why-128284
The leopard slug image is a composite of several references.
Penis worm: Shipley, Arthur Everett (1911). “Priapuloidea”. In Chisholm, Hugh (ed.). Encyclopædia Britannica. 22 (11th ed.). Cambridge University Press. p. 313.
Alligator:
Alligator reference:
edyong209, 2013. Alligator penis surprise. SERIOUSLY WATCH THIS! Youtube. Attributed to Brandon Moore. https://www.youtube.com/watch?v=3ED_exG3qLk&feature=emb_logo&ab_channel=edyong20
Kelly, D.A., 2013. Penile anatomy and hypotheses of erectile function in the American alligator (Alligator mississippiensis): muscular eversion and elastic retraction. The Anatomical Record, 296(3), pp.488-494.
Snake: Keogh, J.S., 1999. Evolutionary implications of hemipenial morphology in the terrestrial Australian elapid snakes. Zoological Journal of the Linnean Society, 125(2), pp.239-278.
Shark: Jones, C.J., Walker, T.I., Bell, J.D., Reardon, M.B., Ambrosio, C.E., Almeida, A. and Hamlett, W.C., 2005. Male genital ducts and copulatory appendages in chondrichthyans. Reproductive Biology and Phylogeny of Chondrichthyes: Sharks, Batoids and Chimaeras, ed. WC Hamlett, pp.361-393.
Baculum: Austin, C.R., and Short, R.V. eds., 1986. Reproduction in Mammals. Cambridge University Press.
Barnacles: Neufeld, C.J. and Palmer, A.R., 2008. Precisely proportioned: intertidal barnacles alter penis form to suit coastal wave action. Proceedings of the Royal Society B: Biological Sciences, 275(1638), pp.1081-1087.
Elephant: 4028mdk09, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
Ostrich: Brennan, P.L. and Prum, R.O., 2012. The erection mechanism of the ratite penis. Journal of Zoology, 286(2), pp.140-144.
Dog: Kleiman, D.G. and Eisenberg, J.F., 1973. Comparisons of canid and felid social systems from an evolutionary perspective. Animal behaviour, 21(4), pp.637-659.
Hart, B.L. and Kitchell, R.L., 1965. External morphology of the erect glans penis of the dog. The Anatomical Record, 152(2), pp.193-198.
Wolvix1965, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:German_Shepherd_penis_1.jpg
References, #DAILY WORM:
Phoronids
birdoptera 
