According to this new stocklist, the zoo holds the following, with the increase from last year in brackets:
Invertebrates: 203 (+30)
Fish: 35 (+4)
Amphibians: 18 (+2)
Reptiles: 25 (+1)
Birds: 86 (+9)
Mammals: 65 (+7)
Total: 432 (+53)
Which means that the total number of species has increased by no less than 54, and all six taxonomic classes have seen a net increase. Baring in mind that the total does include duplicate species (such as the multiple Alpaca breeds), that is still a phenomenal increase, and surely making 2023 one of the best years for collection growth in London Zoo's recent history.
With an increase of 54 species, more than some entire zoos, there are surely plenty of unannounced new arrivals in there, that I will aim to compile a list of later if I have time, but briefly browsing through, two stood out to me. The first is the arrival of 12 Rio Cauca Caecilians (Typhlonectes natans), making the zoo home to three caecilian species and presumably explaining the high number of aquatic caecilians seen during the final days of the Reptile House despite the zoo only housing one aquatic caecilian, a male Cayenne, up until that point. Is there any other zoo in the world which houses three caecilian species? The second was the fact that Alligator Snapping Turtles are listed, a species that, although I could be mistaken, has not been announced as a future display in SLoRA (haven't seen it abbreviated to that prior to Swampy using it upthread, but it works and I will certainly be using it from now on!), but presumably will be if they are held at the zoo. They have been listed on Zootierliste for a month now, allegedly having arrived from Paignton, so it is nice to have confirmation of this from the zoo.