Ungulates
Both: South-East Asian elephant; Grant`s zebra; northern warthog; Reeves' muntjac; Eurasian forest reindeer; Javan banteng
Arnhem
Asian elephant
West Indian manatee
Southern white rhinoceros
Collared peccary
Rothschild's giraffe
Common hog deer; Myanmar thamin
California bighorn; eastern bongo; common waterbuck; roan antelope; beisa oryx; eastern white-bearded wildebeest; western blue duiker
Berlin
Przewalski's horse; Grevy's zebra
Baird's and Brazilian tapirs
Greater one-horned and eastern black rhinoceroses
Red river hog; Bornean bearded and Negros warty pigs; Sulawesi babirusa
Southern white-lipped peccary
Guanaco; Vicuna
Java mouse deer
Giraffe; okapi
Chinese water deer; Persian fallow deer; Visayan spotted and Indian swamp deer; Japanese sika; white-tailed deer; southern pudu
Blackbuck; springbok; southern gerenuk; Kirk's dik-dik; Sichuan takin; Himalayan tahr; Siberian ibex; lowland anoa; Indian gaur; European and plains bison; red buffalo; nyala; western sitatunga; greater kudu; common eland; eastern bongo; defassa waterbuck; Kafue lechwe; black sable antelope; gemsbok; scimitar-horned oryx; blesbok; red duiker
Western pygmy and common hippopotami
Arnhem has a manatee; Berlin has camelids, a chevotrain and hippopotami, so wins on family diversity.
Reptiles
Both: Malaysian giant pond and yellow-spotted Amazon river turtles; red-footed tortoise; common green iguana; Cuban brown anole; green basilisk; central bearded dragon; mourning gecko; common blue-tongued skink; Gila monster; green tree python
Arnhem
Asian leaf turtle; red-eared slider
Guadeloupe anole; common chuckwalla; Tokay gecko; desert spiny and collared lizards; Asian water monitor
Reticulated python; California king and Sinaloan milk snakes; red diamond rattlesnake
Broad-snouted caiman
Berlin
Central American wood, red-cheeked and scorpion mud, Siebenrock's and South American snake-necked, Hilaire's side-necked, pig-nosed, Mississippi map, red-bellied short-necked and common musk turtles; mata-mata; Malagasy spider, radiated, yellow-footed and leopard tortoises; yellow-bellied slider
Tuatara
Common spiny-tailed, Guatemalan spiny-tailed, Hispaniolan rhinoceros, Oaxacan spiny-tailed and Fiji short-crested iguanas; Knight anole; brown basilisk; Cuvier's Madagascar swift; Savigny's agama; black hardun; Baja California rock, blue spiny, Bosk's fringe-toed, four-lined girdled, caiman, frill-necked, giant plated, tropical girdled, green keel-bellied, Oman spiny-tailed, Philippine sailfin, red-sided curly-tailed and blue rainbow lizards; Common leopard and Bibron's thick-toed geckos; Cunningham's and prehensile-tailed skinks; ornate mastigure; panther and veiled chameleons; Chinese and Australian water dragons; Mexican beaded lizard; blue-spotted tree, Mertens' water, northern Pilbara rock, spiny-tailed and freckled monitors
Boa constrictor; Brazilian rainbow, Cuban tree, Puerto Rican and Jamaican boas; yellow anaconda; Burmese rock, spotted, woma and Savu pythons; cave beauty, Honduran milk, red-tailed rat, beauty and corn snakes; common and yellow-lipped sea kraits; Trans-Pecos copperhead; western diamondback rattlesnake
Smooth-fronted and spectacled caimans; gharial
Berlin has a tuatara and wins on order diversity.
Amphibians
Both: Mission golden-eyed tree frog
Arnhem
Montserrat whistling frog; Colorado River toad
Berlin
Cayenne and Rio Cauca caecilians
Algerian ribbed, Okinawa sword-tail, emperor, Chinese warty, Italian alpine, Kaiser's spotted and Himalayan newts; axolotl; banded fire and barred and eastern tiger salamanders; lesser siren
African bullfrog; common reed, greenhouse, Sambava tomato, painted-belly and tiger-striped leaf, Riobamba marsupial, orange-legged monkey, yellow stream, long-nosed horned and Budgett’s frogs; Congo dwarf and African clawed frog; American and Australian green, Chinese gliding, spot-legged, clown, Cuban, file-eared, European, Mediterranean, Spurrell's, Morelet’s and barking tree frogs; Amazonian, splashback, strawberry, spotte and golden poison frogs; Blue, green and black, yellow-banded and Golfodulcean poison and dyeing dart frogs; Anthony’s poison-arrow frog; African, bumble bee, Common Indian, green, European green, Sabana Surinam, Perak horned, yellow-bellied, Surinam, Klappenbach’s red-belly, marine, oriental fire-bellied, spotted and Brongersma's toads;
Berlin has caecilians and salamanders and wins on order diversity
I started trying to compare the fish of Arnhem and Berlin, but Berlin's collection seems to have changed since yesterday. Suffice it to say, Berlin has a much larger and more varied collection and wins on diversity.
Berlin wins in all categories.