Field of Science

The Rosy Birds

Violet-necked lories Eos squamata, copyright Niels Poul Dreyer.


In taxonomic days of yore, it was a not uncommon practice for new genera to be baptised under the names of classical figures: gods, heroes, emperors, even the occasional prophet (the practice only died down once the barrel of available names became largely empty). In many cases, the connection drawn between the organism in question and its awarded namesake was tenuous at best. In others, it was simply non-existent. But in a favoured few cases, the association fit perfectly.

Eos is a small genus (recent authors have recognised six species) of lories found on islands in eastern Indonesia. They are named, of course, after the Ἠώς ῥοδοδάκτυλος, the 'rosy-fingered dawn', of the ancient Greeks. It takes no great insight to realise why they were so-called: all members of the genus are predominantly coloured in a vibrant red, together with varying extents of blue, purple and/or black. Green is usually absent from their plumage (with some noteworthy exceptions that I'll have cause to mention again), distinguishing them from most closely related parrots such as the rainbow lorikeets in the genus Trichoglossus. Charles Lucien Bonaparte (nephew to the other Bonaparte, and a prominent nineteenth-century ornithologist) stated in 1850 that Eos could be recognised by its "elegant form, small stature, compact, red plumage with more or less blue; compressed, moderate, red bill, with the cere apparent... and longish, not very broad, wedged tail".

Blue-streaked lories Eos reticulata, copyright Doug Janson.


For the most part, Eos species are found on islands between Sulawesi and New Guinea. The black-winged lory Eos cyanogenia is found on islands in Geelvink Bay, in the north-west part of West Papua, but not on the mainland of New Guinea itself. For the most part, no island is home to more than one species of Eos. The island of Seram is an exception, with the endemic blue-eared lory Eos semilarvata found in the central highlands, and the red lory Eos whatchumacallit (see below) closer to the coast (this species is also found on other islands in the South Moluccas). The blue-streaked lory Eos reticulata is found in the Tanimbar group east of Timor. The violet-necked lory Eos squamata lays claim to the North Moluccas, and the red-and-blue lory Eos histrio is found on Talaud and other islands to the north-west of Sulawesi (Juniper & Parr 1998).

Black-winged lory Eos cyanogenia, copyright Lip Kee Yap.


While the taxonomy of the group has been mostly stable in recent years, it was not always so. Bonaparte (1850) snidely commented that some species of Eos had been described "too many times". Hume & Walters (2012) referred to five described species of Eos, all based on isolated specimens since lost, whose identity has been contested. While it is possible that some may represent species now extinct, it is equally possible that they represented unusual individuals of living species. In the absence of examinable type specimens, the identity of most is of academic interest only. The exception is the 'red-and-green lory' Eos bornea, which was originally named Psittacus borneus by old Carolus Linnaeus himself on the basis of a description and plate of a lory supposedly from Borneo published in 1751 by George Edwards (Walters 1998). Edwards' bird, which he had bought as a stuffed specimen from a toyshop in London, was described as dark pink, with a yellow bill, and green patches on the wings and tail. However, no species quite matching Edwards' description is known from Borneo or anywhere else, and it was subsequently suggested that he may had an unusual or a faded specimen of the Moluccan red lory, with the Bornean locality being an error. As such, the name Eos bornea came into use for the red lory, replacing the later-published name 'Eos rubra'. However, Walters (1998) subsequently disputed this identification, recommending the continued use of E. rubra. At present, 'Eos bornea' still seems to be the more commonly used name, and my own sympathies would be more with maintaining the familiar usage than with insisting on strict adherence to the original concept.

Red lories, Eos... let's just say bornea, shall we? Copyright Arnaud Delberghe.


Because of their striking appearance, Eos species have been heavily collected for the pet trade. The have also been widely affected by habitat degradation with the clearing of primary forests. While populations of most species are still regarded as reasonably robust, the IUCN regards all except E. squamata as on the decline. Eos histrio is regarded as actively endangered, having all but disappeared from some of its home islands. In 1999, it was estimated that 1000 to 2000 red-and-blue lories were being captured and exported for the pet trade each year—despite the total population of this species probably being not much more than 20,000 individuals!

REFERENCES

Bonaparte, C. L. 1850. On the trichoglossine genus of parrots, Eos, with the description of two new species. Proceedings of the Zoological Society of London 18 (1): 26-29.

Hume, J. P., & M. Walters. 2012. Extinct Birds. T. & A. D. Poyser.

Juniper, T., & M. Parr. 1998. Parrots: A guide to the parrots of the world. Christopher Helm Publishers.

Walters, M. 1998. What is Psittacus borneus Linnaeus? Forktail 13: 124-125.

In a Pufferfish's Garden

Bullseye puffer Sphoeroides annulatus, copyright Geoffrey W. Schultz.


I don't know if it applies in other parts of the world, but one animal that you are guaranteed to see in the estuary here in Perth is pufferfish. One of the most instantly recognisable fish families, pufferfish (Tetraodontidae) are of course famed for their high toxicity, the determination of some people to eat them despite aforementioned toxicity, and their habit of swallowing air or water when threatened to inflate their distendible bellies. That last feature makes them a favourite of children (or at least of yours truly as a child), because their slow swimming style makes them one of the few fish that can be easily captured by hand (you just have to make sure you don't allow the fish to give you a nasty bite with their beak). The first feature makes them a lot less popular with fishermen who have to experience the frustration of reeling in a line to find that the bait has been taken by a puffer, then trying to remove the puffer from the hook while avoiding the aforementioned beak.

Oceanic puffer Lagocephalus lagocephalus, from Baino96.


There are a little under 200 known pufferfish species worldwide. Most of them are found in coastal marine and brackish waters, but there are also several species found in fresh water in South America, Africa and southeast Asia. Some marine species are also resistant to fresh water and may spend extended periods away from the sea. Some southeast Asian brackish-water Tetraodon species even make regular appearances in the the aquarium trade labelled as 'freshwater' puffers (Yamanoue et al. 2011), though their long-term survival requires more appropriate water conditions. The toxin associated with pufferfishes is not produced by the fish itself, but accumulated through its diet. As such, the exact level of toxicity of a pufferfish may vary according to season.

Grass puffer Takifugu niphobles, copyright OpenCage.


A molecular phylogenetic analysis of pufferfish by Yamanoue et al. (2011) identified four main clades in the family. These clades were also supported by a subsequent analysis by Santini et al. (2013), though the deeper relationships between the clades differed between the analyses. Yamanoue et al. (2011) identified a small number of freshwater clades (only one for each continent with freshwater taxa) and inferred that the transition from marine to fresh water had happened only rarely. Santini et al. (2013), in contrast, supported a higher number of transitions in tetraodontid history, though at least some of the difference between the two studies can be explained by differing definitions of 'freshwater'. For instance, some species of Takifugu usually live in brackish water but spawn in fresh water; Santini et al. counted these as freshwater species, but Yamanoue et al. did not.

Papuan toby Canthigaster papua, photographed by Dwayne Meadows.


One of the major clades identified within the Tetraodontidae includes the genus Lagocephalus, a group of relatively long-bodied puffers including some of the few pelagic puffer species. This genus may be the sister taxon of the remaining puffers (as found by Yamanoue et al.), or it may have a more nested position as sister to a clade including the mostly West Atlantic-East Pacific genera Sphoeroides and Colomesus (as found by Santini et al.). This latter clade includes South America's only freshwater puffer, the Amazon species Colomesus asellus. Santini et al. identified the basalmost tetraodontid clade as an Indo-West Pacific assemblage including the genus Takifugu and related taxa, which Yamanoue et al. had found as sister to the final clade including taxa related to the genus Tetraodon. This last clade includes the African and southeast Asian freshwater puffers (except for a few members of the Takifugu clade that cross into fresh water at times). It also includes the genus Canthigaster, the sharpnose pufferfish. In contrast to the more or less globular form of all other puffers, sharpnose puffers have a laterally compressed body form that superficially looks a bit more like a triggerfish than a puffer. Most Canthigaster species are reef-dwellers, a somewhat unusual habitat for a puffer (the other main group of reef-dwelling puffers being the genus Arothron, also in the Tetraodon clade).

Circular underwater 'nest' constructed by a pufferfish, from Spoon & Tamago.


One of the most remarkable characteristics of any puffer, though, was not discovered until quite recently. In 2012, it was announced that large structures observed off the coast of Japan by underwater photographer Yoji Ookata were in fact the work of pufferfish. These structures, circular and regular geometric patterns in the sea bed about 1.5 metres in diameter, were made by male puffers swimming against the sand. The structures are believed to function in attracting females, and also function as nests in which the females lay their eggs. Rather frustratingly, I haven't found any indication exactly which species of puffer is involved!

Puffer in the process of building a nest, also from Spoon & Tamago.


REFERENCES

Santini, F., M. T. T. Nguyen, L. Sorenson, T. B. Waltzek, J. W. Lynch Alfaro, J. M. Eastman & M. E. Alfaro. 2013. Do habitat shifts drive diversification in teleost fishes? An example from the pufferfishes (Tetraodontidae). Journal of Evolutionary Biology. doi: 10.1111/jeb.12112.

Yamanoue, Y., M. Miya, H. Doi, K. Mabuchi, H. Sakai & M. Nishida. 2011. Multiple invasions into freshwater by pufferfishes (Teleostei: Tetraodontidae): a mitogenomic perspective. PLoS ONE 6 (2): e17410. doi:10.1371/journal.pone.0017410.