by Piter Kehoma Boll
This post is a continuation of The history of Systematics: Animals in Systema Naturae, 1758 (part 1). So be sure to read that first!
Here I’ll talk about two other classes in Linnaeus’ classification: Amphibia and Pisces.
3. Amphibia (Amphibians)
Heart with one ventricle and one auricle; cold, red blood.
Lungs breathing arbitrarily.
Penis double. Eggs mostly membranaceous.
Senses: tongue, nostrils, eyes, many ears.
Covering: coriaceous, nude.
Support: various, in some none.
Amphibians were classified according to the anatomy of the limbs and included 3 orders: Reptiles, Serpentes, and Nantes. They are shown below with their respective genera.
3.1 Reptiles (crawlers), having four feet : Testudo (turtles and tortoises), Draco (gliding lizards), Lacerta (lizards, salamanders and crocodilians), Rana (frogs and toads).
Four species that Linnaeus put under Reptiles (from left to right): spur-thighed tortoise (Testudo graeca), flying lizard (Draco volans), sand lizard (Lacerta agilis), and common frog (Rana temporaria). Credits to Gisella D. (tortoise), Charles J. Sharp (flying lizard), Krzysztof Mizera (sand lizard), and Monika Betley (frog).
3.2 Serpentes (creepers), without limbs: Crotalus (rattlesnakes), Boa (boas), Coluber (racers, vipers, cobras, pythons), Anguis (slow worms, worm snakes and sand boas), Amphisbaena (worm lizards), Caecilia (caecilians).
Six species put by Linnaeus under Serpentes (from left to right, top to bottom): timber rattlesnake (Crotalus horridus), Boa constrictor, black racer (Coluber constrictor), slow worm (Anguis fragilis), red worm lizard (Amphisbaena alba), and bearded caecilian (Caecilia tentaculata). Credits to Pavel Ševela (boa constrictor), Wikimedia user Marek_bydg (slow worm), Diogo B. Provete (worm lizard)**, and bio-scene.org (bearded cacecilian).
3.2 Nantes (swimmers), having fins: Petromyzon (lampreys), Raja (rays), Squalus (sharks), Chimaera (ratfishes), Lophius (anglerfishes), and Acipenser (sturgeons).
The order Nantes comprised, among others (from left to right, top to bottom), the sea lamprey (Petrozymon marinus), the thornback ray (Raja clavata), the spiny dogfish (Squalus acanthias), the rabbitfish (Chimaera monstrosa), the angler (Lophius piscatorius), and the sturgeon (Acipenser sturio). Credits to Wikimedia user Fungus Guy (lamprey), Wikimedia user Citron (rabbitfish), Wikimedia user Meocrisis (angler), and flickr user Aah-Yeah (sturgeon).
4. Pisces (Fish)
Heart with one ventricle and one auricle; cold red blood.
Gills external, compressed.
Penis absent. Eggs without albumin.
Senses: tongue, nostrils (?), eyes (no ears).
Covering: imbricate scales.
Fish included 5 orders, which were defined mainly by the position of the ventral limbs in relation to the pectoral fins: Apodes, Jugulares, Thoracici, Abdominales and Branchiostegi.
4.1 Apodes (footless ones), without ventral fins: Muraena (eels), Gymnotus (knifefishes), Trichiurus (cutlassfishes), Anarhichas (wolffishes), Ammodytes (sand eels), Stromateus (butterfishes), Xiphias (swordfishes).
(From left to right, top to bottom) The Mediterranean muray (Muraena helena), banded knifefish (Gymnotus carapo), largehead hairtail (Trichiurus lepturus), seawolf (Anarhichas lupus), lesser sand eel (Ammodytes tobianus), blue butterfish (Stromateus fiatola), and swordfish (Xiphias gladius) were classified as Apodes. Credits to Tato Grasso (muray), segrestfarms.com (knifefish), Daizu Azuma (hairfail), Wikimedia user Haplochromis (seawolf), and Muhammad Moazzam Khan (swordfish).
4.2 Jugulares (jugular ones), ventral fins in front of the pectoral fins: Callionymus (dragonets and flatheads), Uranoscopus (stargazers), Trachinus (weevers), Gadus (cods, haddocks, lings, etc), Blennius (blennies), Ophidion (cusk-eels, gunnels, bandfishes).
Six species included in the order Jugulares (from left to right, top to bottom): common dragonet (Callionymus lyra), Atlantic stargazer (Uranoscopus scaber), greater weever (Trachinus draco), Atlantic cod (Gadus morhua), butterfly blenny (Blennius ocellaris), snake blenny (Ophidion barbatum). Credits to Hans Hillewaert (dragonet), Roberto Pillon (stargazer), Hans-Petter Fjeld (cod, CC-BY-SA), Gianni Neto (blenny), Stefano Guerrieri (snake blenny).
4.3 Thoracici (thoracic ones), ventral fins below the pectoral fins: Cyclopterus (lumpfishes), Echeneis (remoras), Coryphaena (dolphinfishes and razorfishes), Gobius (gobies), Cottus (sculpins and hooknoses), Scorpaena (scorpionfishes), Zeus (John dories, lookdowns and boar fishes), Pleuronectes (flatfishes), Chaetodon (butterflyfishes, angelfishes, surgeons, etc), Sparus (breams, porgies, picarels, etc), Labrus (wrasses, parrotfishes, etc), Sciaena (snappers and croakers), Perca (perch, groupers, tilapias, etc), Gasterosteus (sticklebacks, lionfishes, pilot fishes, etc), Scomber (mackerels and tunas), Mullus (goatfishes), and Trigla (gurnards).
Seveteen species classified by Linnaeus as Thoracici (from left to right, top to bottom): lumpsucker (Cyclopterus lumpus), live sharksucker (Echeneis naucrates), pompano dolphinfish (Coryphaena equiselis), black goby (Gobius niger), European bullhead (Cottus gobio), bigscale scorpionfish (Scorpaena scrofa), John Dory (Zeus faber), European plaice (Pleuronectes platessa), banded butterflyfish (Chaetodon striatus), gilt-head bream (Sparus aurata), brown wrasse (Labrus merula), brown meagre (Sciaena umbra), European perch (Perca fluviatilis), three-spined stickleback (Gasterosteus aculeatus), Atlantic mackereil (Scomber scombrus), bluntsnouted mullet (Mullus barbatus), and piper gurnard (Trigla lyra). Credits to Simon Pierre Barrette (lumpsucker), Wikimedia user Wusel007 (sharksucker), NOAA/FPIR Observer Program (dolphinfish), Stefano Guerrieri (goby and wrasse), Hans Hillewaert (bullhead), Wikimedia user Elapied (scorpionfish), Wikimedia user Kleines.Opossum (john dory), Wikimedia user Gargolla (plaice), Bernard E. Picton (butterflyfish), Roberto Pillon (bream and mullet), Albert Kok (meagre), Wikimedia user Dgp.martin (perch), Wikimedia user JaySo83 (stickleback), NOAA (mackerel), and Massimiliano Marcelli (gurnard).
4.4 Abdominales (abdominal ones), ventral fins behind the pectoral fins: Cobitis (loaches and four-eyed fishes), Silurus (catfishes), Loricaria (suckermouth catfishes), Salmo (salmon, trouts, smelts, etc), Fistularia (cornetfishes), Esox (pikes, gars, barracudas, etc), Argentina (herring smelts), Atherina (silversides), Mugil (mullets), Exocoetus (flying fishes), Polynemus (threadfins), Clupea (herring, anchovies, hatchetfishes, etc), and Cyprinus (carps, goldfishes, breams, etc).
Thirteen species that were part of the order Abdominales (from left to right, top to bottom): spined loach (Cobitis taenia), Wels catfish (Silurus glanis), suckermouth catfish (Loricaria cataphracta), Atlantic salmon (Salmo salar), bluespotted cornetfish (Fistularia tabacaria), northern pike (Esox lucius), European argentine (Argentina sphyraena), Mediterranean sand smelt (Atherina hepsetus), flathead mullet (Mugil cephalus), Tropical two-winged flying fish (Exocoetus volitans), paradise threadfin (Polynemus paradiseus), Atlantic herring (Clupea harengus), and common carp (Cyprinus carpio). Credits to J. C. Harf (loach), Dieter Florian (catfish), Hans-Petter Fjeld (salmon), Wikimedia user Jik jik (pike), Roberto Pillon (sand smelt and mullet), Wikimedia user Kolisberg (flying fish), segrestfarms.com (threadfin), and Wikimedia user Kils (herring).
4.5 Branchiostegi, lacking opercula or branchial fins: Mormyrus (elephantfishes), Balistes (triggerfishes and snipefishes), Ostracion (boxfishes, cowfishes, etc), Tetraodon (pufferfishes and sunfishes), Diodon (porcupine fishes), Centriscus (shrimpfishes), Syngnathus (pipefishes and seahorses), and Pegasus (seamoths).
The eight species shown above were all part of the order Branchiostegi (from left to right, top to bottom): Mormyrus caschive, queen triggerfish (Balistes vetula), yellow boxfish (Ostracion cubicus), Fahaka pufferfish (Tetraodon lineatus), spot-fin porcupinefish (Diodon hystrix), grooved shrimpfish (Centriscus scutatus), common pipefish (Syngnathus acus), and longtail seamoth (Pegasus volitans). Credits to Johny Jensen (Mormyrus), James St. John (triggerfish), flickr user zsispeo (boxfish), Reserva de la Biosfera Cabildo de Gran Canaria (porcupinefish), John E. Randall (shrimpfish and seamoth), and Hans Hillewaert (pipefish).
As you can notice, Linnaeus’ classification of amphibians and fish was even worse than that of mammals and birds, especially the classification of amphibians. It is clear that Linnaeus hated what he called amphibians more than anything. He describes them as the worst creatures, having a horrible appearence, and thanking God for not creating many of them.
Probably one of the most bizarre things is that Linnaeus put lizards and crocodiles in the same genus! Well, if he hated “amphibians” so much, I think he was not very familiar with their anatomy.
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Linnaeus, Carl. 1758. Systema Naturae per Regna Tria Nature…
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