Field of Science

A King among Parrots

Moluccan King parrot Alisterus amboinensis, photographed by Helsinki***.


For today's post, I'm looking at the King parrots of the genus Alisterus. There are three recognised species in this genus: the Australian King parrot Alisterus scapularis of eastern Australia, the green-winged or Papuan King parrot A. chloropterus of central and eastern New Guinea, and the Amboina or Moluccan King parrot A. amboinensis of eastern Indonesia and western Papua. However, each species is divided into subspecies, and some subspecies are quite distinct from each other. For instance, Alisterus scapularis shows distinct sexual dimorphism: the male has a bright red head and breast while the female has a green head and breast. In A. amboinensis, both sexes have red heads. In A. chloropterus, the nominate subspecies has a green-headed female like that of A. scapularis, but the northwesternmost subspecies A. chloropterus moszkowskii has a red-headed female like that of A. amboinensis (Forshaw & Knight 2010). In relation to other parrots, Alisterus belongs to the tribe Psittaculini that extends into eastern and southern Asia and the Mascarenes, among which it forms a clade with the other Australian genera Aprosmictus and Polytelis (Mayr 2010) (and hybrids have even been recorded between A. scapularis and species of these two genera—Rutgers & Norris 1972).

Female (left) and male Australian King parrot Alisterus scapularis, photographed by Peter Firminger.


You might be wondering why, among an entire order of particularly regal birds, it is this particular genus that is honoured with the title of 'King' (I know I certainly did). As it turns out, the reason appears to be that Alisterus is not, properly speaking, the 'king of parrots', but 'King's parrot', named after Philip Gidley King, governor of New South Wales from 1800 to 1806 ('Stentoreus' 2004; I might as well also point out for the benefit of those not familiar with Australian history that the original 'New South Wales' was considerably larger than the current state by that name, taking in the entire eastern seaboard of Australia).

Papuan King parrot Alisterus chloropterus, photographed by Mehd Halaouate.


King parrots are generalist feeders on fruit and seeds, which has not always endeared them to horticulturalists. They nest in deep holes in hollow trees: while the entrance to an Alisterus scapularis nest may be more than nine metres high, the actual nest may be nearly at ground level (Rutgers & Norris 1972). They lay 3-6 eggs between October and December.

REFERENCES

Forshaw, J. M., & F. Knight. 2010. Parrots of the World. Princeton University Press.

Mayr, G. 2010. Parrot interrelationships—morphology and the new molecular phylogenies. Emu 110: 348-357.

Rutgers, A., & K. A. Norris. 1972. Encyclopaedia of Aviculture vol. 2. Blandford Press: London.

Hunters in the Deep Sea

Longnose lancetfish Alepisaurus ferox, photographed by Paulo De Oliveira.


For today's post, I'm going to tackle the Alepisauroidei. The exact scope of this clade of fishes has changed a bit between authors; here, I'm focusing on the restricted sense used by Sato & Nakabo (2002). In contrast, Davis & Fielitz (2010) used 'Alepisauroidei' in a broader sense that combined the Alepisauroidei, Chlorophthalmoidei and Giganturoidei of the former authors; if I have to refer to this larger clade, it'll be as 'Alepisauroidei sensu lato'.

Tedious definitionising aside, the Alepisauroidei sensu stricto include the living families Scopelarchidae, Evermannellidae, Alepisauridae and Paralepididae. All members of these families are predators in the mesopelagic zone of the ocean, below the level of the light. Members of the Alepisauridae (lancetfishes) and Paralepididae (barracudinas) are elongate, reaching lengths of over a metre in the case of the lancetfishes. Many mesopelagic fish migrate closer to the surface at night, and Bond (1996) refers to lancetfishes being caught by anglers standing on the shore during spring in the Pacific Northwest of North America. The predatory nature of the alepisauroids, as well as something of their general appearance, can be inferred from the common names given to many of them: as well as the barracudinas already mentioned, there are the sabretooth fishes of the Evermannellidae, and the daggertooth Anotopterus pharao.

An array of alepisauroids, from here. Species shown are: (Paralepididae) (1) Stemonosudis rothschildi, (2) Lestidium atlanticum, (3) Lestrolepis intermedia, (Evermannellidae) (4) Coccorella atlantica, (5) Evermannella indica, (Scopelarchidae) (6) Scopelarchus analis.


Alepisauroids show many of the adaptations common among deep-water fishes, such as the presence of bioluminescent organs (absent in Alepisauridae) and thin-walled, distensible stomachs allowing the immediate engulfment of large prey items. In the evermannellid genus Coccorella, the caecum of the intestine has become expanded to the extent that part of it actually extends into the animal's head and can be seen in the base of the oral cavity (Wassersug & Johnson 1976). The members of the family Scopelarchidae are known as pearleyes due to their enlarged, dorsally-directed tubular eyes (also present in the Evermannellidae) that presumably increase their ability to detect the limited light filtering down from above (and, more importantly, from the bioluminescent organs of other mesopelagic animals). Another notable adaptation to the mesopelagic environment present in all alepisauroids is that they are simultaneous hermaphrodites: each individual has fully functional male and female reproductive organs. In an environment where the usual scarcity of food items means that species exist at very low population densities, simultaneous hermaphroditism means that any other individual of your species is a potential mate. Simultaneous hermaphroditism is also found in other members of the Alepisauroidei sensu lato, making it the largest clade of vertebrates utilising this reproductive strategy (Davis & Fielitz 2010).

Specimen of daggertooth Anotopterus vorax, photographed by Peter Marriott.


A comprehensive investigation of the molecular phylogeny of alepisauroids was published by Davis & Fielitz (2010). Evermannellids and scopelarchids were resolved as successive sister groups to the other alepisauroids sensu stricto, suggesting that their tubular eyes may have arisen independently (as corroborated by their absence in the evermannellid genus Odontostomops; alternatively, tubular eyes could have been lost in other alepisauroids). The Alepisauridae were nested within an apparently paraphyletic Paralepididae. The clade as a whole was suggested by molecular dating to have diverged some time in the Early Cretaceous, a result in concordance with the known fossil record.

REFERENCES

Bond, C. E. 1996. Biology of Fishes, 2nd ed. Saunders College Publishing.

Davis, M. P., & C. Fielitz. 2010. Estimating divergence times of lizardfishes and their allies (Euteleostei: Aulopiformes) and the timing of deep-sea adaptations. Molecular Phylogenetics and Evolution 57: 1194-1208.

Sato, T., & T. Nakabo. 2002. Paraulopidae and Paraulopus, a new family and genus of aulopiform fishes with revised relationships within the order. Ichthyological Research 49 (1): 25-46.

Wassersug, R. J., & R. K. Johnson. 1976. A remarkable pyloric caecum in the evermannellid genus Coccorella with notes on gut structure and function in alepisauroid fishes (Pisces, Myctophiformes). Journal of Zoology 179 (2): 273-289.

Fifteen Seconds of Mediocrity

Specimen assigned to 'Gemmula aff. G. asukana' by MacNeil (1960).


This is going to be another one of those posts where I try to actually build something on the back of some obscure taxon about which I've only managed to find enough to fill about two sentences. You have been warned.

Kuroshioturris asukana was described as Drillia asukana by Yokoyama in 1926 in the Journal of the Faculty of Science, Imperial University of Tokyo. That might in itself explain why I haven't been able to access the original description (for my American readers, the appropriate issue is on Google Books here, in case this is another one that Google is only making available within the United States). The species is a Pliocene member from Japan of the gastropod superfamily Conoidea, the 'poison-tongued' gastropods, in the family Turridae. The exact position of asukana in the turrids has shifted around a bit: it has appeared in Clavatula, in Gemmula, in (the most horrifying turrid genus of all) Pleurotoma, before Powell (1966) placed it into Kuroshioturris (treated by Powell as a subgenus of Ptychosyrinx, but as a separate genus by later authors such as Beu 2011). A second specimen other than the holotype assigned by Yokoyama to Pleurotoma asukana in 1928 may not in fact be the same species, and MacNeil (1960) noted that the holotype appeared to be a juvenile, further complicating identification.

The type species of Kuroshioturris, K. hyugaensis, from the East China Sea. Photo from here.


Powell (1966) stated that Kuroshioturris was restricted to the Miocene and Pliocene of Japan, but this was an error. Two of the species listed by Powell (including the type species of the genus) are in fact members of the Recent fauna. Beu (2011) also assigned two species from the Pliocene to Recent of New Zealand to Kuroshioturris. Powell distinguished Kuroshioturris from Ptychosyrinx sensu stricto on the basis of the protoconch morphology, noting that the adult shell was otherwise nearly identical. However, other cases of conoid genera being separated solely on the basis of protoconch form have since been regarded as invalid (Beu 2011). Protoconch morphology often reflects to mode of larval lifestyle for the animal: a tall, narrow protoconch (such as in Ptychosyrinx) indicates an actively feeding, planktotrophic larva, while a blunt, short protoconch indicates a lecithotrophic larva nourished by yolk reserves. Changes from one nutritional mode to another seem to have happened repeatedly, leading to cases such as the lecithotrophic 'genus' Maoritomella turning out to be a polyphyletic assemblage of Tomopleura species that had independently abandoned planktotrophy. Many such genera have now been synonymised, but many (such as Kuroshioturris?) still require examination.

REFERENCES

Beu, A. G. 2011. Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia). Journal of the Royal Society of New Zealand 41 (1): 1-153.

MacNeil, F. S. 1960. Tertiary and Quaternary Gastropoda of Okinawa. Geological Survey Professional Paper 339.

Powell, A. W. B. 1966. The molluscan families Speightiidae and Turridae: an evaluation of the valid taxa, both Recent and fossil, with lists of characteristic species. Bulletin of the Auckland Institute and Museum 5: 1-184, pls 1-23.

I Hate Everything Right Now

For the last week, I have been caught in the grip of a particularly vindictive cold. Which is why, when I thought of this particularly painful little pun earlier, I didn't allow it to sink back into the depths of drollery hell like I should have, but decided to inflict it upon the larger world. Why should I suffer alone?

A patient is being given some test results by a doctor. The doctor looks at his notes and says, "I'm sorry to tell you this, but your lungs appear to be infested with Mesozoic mammals". Aghast, the patient asks hesistantly, "You don't mean...?" "I'm afraid so", replies the doctor. "You have multituberculosis".

Colour vs Crypsis

The southeast Asian Lyssa zampa, a large nocturnal uraniine. Photograph by Alexey Yakovlev.


Even if you don't know much about insects, you've probably been taught the difference between a butterfly and a moth. Butterflies are ornate, colourful and active during the day, while moths are... ornate, colourful and active during the day?

A cryptic epiplemine Crypsicoela subocellata, photographed by Stephen Luk.


The Uraniidae are a family of about 700 species of mostly pantropical moth. The family is united primarily by their distinctive sexually dimorphic tympanal organs: in females, the tympanal organs open ventrally on the first abdominal sternite (as in a number of other moths), but in males they open dorsally or laterally at the junction of the second and third segments (Scoble 1995). About 600 of the 700 species of uraniid are assigned to the subfamily Epipleminae, and are generally nocturnal, brown and cryptic. Many epiplemines roll their wings up when at rest, so that they resemble a small brown stick.

The South American migratory Urania fulgens. Photo from here.


However, some members of the subfamily Uraniinae have become diurnal. These diurnal species have brightly iridescent wings with prominent tails, and have often been compared to swallowtail butterflies. One of the best-known species is Urania fulgens, a South American species that migrates north into Central America at certain times of year. Migrating individuals may reach as far north as the southern United States.

REFERENCES

Scoble, M. J. 1995. The Lepidoptera: Form, function and diversity. Oxford University Press.

It's Nematodes All the Way Down

Halicephalobus mephisto, as illustrated by Borgonie et al. 2011.


It has to be said, nematodes are not among the most loved of organisms. For the most part, the only nematodes that get any press are either the developmental model animal Caenorhabditis elegans or the small proportion of species that affect us economically as parasites of ourselves or our food sources. There are not thriving clubs of amateur nematologists, there are no news-groups where nematode spotters eagerly spread the news of their latest desmoscolecid sighting. So it suggests something out of the ordinary may be going on when a new nematode species makes its debut in the pages of Nature, as one did today (Borgonie et al. 2011).

Appearance-wise, Halicephalobus mephisto is fairly ordinary (most nematodes are). It does have a higher-than-usual temperature resistance, being able to live in temperatures up to 41°C, but this is not extreme. Nor is the new species' ability to tolerate low oxygen concentrations, a common ability among minute animals such as nematodes and tardigrades. What is unusual about H. mephisto is where it was found: some 1.3 km beneath the surface of the Earth. Halicephalobus mephisto was recovered from fracture water (that is, water that was sitting in a fracture within the rock) in South Africa that had been isolated from the rest of the world for somewhere between 3000 and 12000 years, before being broken into by the Beatrix gold mine.

The presence of living organisms at this depth was not unexpected: bacteria had been found in fracture water previously. Nevertheless, this is the first time that a multicellular animal has been found at this depth. A samples taken in another mine at a depth of 0.9 km also recovered nematodes: one belonging to a previously known species, Plectus aquatilis, and one belong to an unidentifiable species of the family Monhysteridae. A sample taken at a depth of 3.6 km in a third mine did not recover any specimens, but did allow the recovery of nematode DNA suggesting their possible presence. Samples from the soil surrounding the boreholes from which the water samples were taken, as well as samples of the water used in drilling the mines themselves, were tested to establish that the nematodes were indeed from the original fracture water and not recent contaminants, but these control samples were nematode-free.

Halicephalobus mephisto lives a life completely isolated from the surface world, presumably feeding on the bacterial biofilms growing along the edge of the fracture. It would not be abundant: in the Beatrix mine sample, 6480 litres of water were filtered but only a single nematode was recovered (thankfully, the parthenogenetic nematode was successfully raised and bred in the lab, providing the necessary specimens for the species description). But it provides further support for the principal that where there is liquid water, there is life.

REFERENCE

Borgonie, G., A. García-Moyano, D. Litthauer, W. Bert, A. Bester, E. van Heerden, C. Möller, M. Erasmus & T. C. Onstott. 2011. Nematoda from the terrestrial deep subsurface of South Africa. Nature 474: 79-82.