Deceptive and Poisonous Sisters

Iphicleola sister Adelpha iphicleola, photographed by Arthur Chapman.

The butterfly genus Adelpha includes 85 species, many with multiple subspecies, found widely in North and South America (Willmott 2003a). Some of you may recognise 'adelpha' as the Greek word for 'sister', which is also the vernacular name for these butterflies. Supposedly, the white stripes on the wings of many species resemble the edges of a nun's habit (or, at least, so sayeth Wikipedia). The sisters belong to a group of butterflies called the Limenitidini, members of which tend to sit with their wings open when resting, and have a distinctive gliding flight pattern in which the wing tips are pointed downwards (Willmott 2003b). Adelpha is the only genus of Limenitidini found in South America. In North America, Adelpha bredowii is found as far north as Oregon, while in South America species are found down to Uruguay. Not surprisingly, the highest diversity is found in the tropics, though some species are relatively uncommon throughout their ranges (Willmott 2003a).

As caterpillars, Adelpha species feed on a wide variety of food plants, with individual species varying from very host-specific species to broadly catholic species. As befits Neotropical caterpillars, some species possess a ludicrous array of protrusions and outgrowths:

Caterpillar of Adelpha serpa selerio, photographed by Artour A.
When feeding on a leaf, the caterpillars leave the midrib intact, and use it as a support when resting. Over time, they extend the midrib using a combination of faecal pellets and silk to extend their support, and they also sit on this support when moulting. After moulting to the final larval instar, they leave the support and rest on the upper leaf surface. They also attach masses of mixed silk and faecal pellets to the base of their support or hanging off it. One species, Adelpha basiloides, builds small, curved, larva-shaped faecal masses that it places on the leaf surface several millimetres away from its support: Aiello (1984) speculated that these might functions as decoys to distract potential predators from the real caterpillar.

Arizona sister Adelpha eulalia, photographed by Tom Bentley.

The adults of Adelpha have a reputation for being tricky to identify; DeVries described them as "the most difficult and trying taxonomically of all the nymphalids". For a long time, Adelpha species were divided into groups on the basis of their wing patterning, but comparisons with other features such as caterpillar morphology have revealed that species with similar wing patterns are often not closely related (Aiello 1984; Willmott 2003b). Instead, it has been suggested that mimicry has been a significant factor in the genus' evolution: certain species feeding as caterpillars on toxic plants such as members of the Rubiaceae (and hence sequestering the plant toxins to render themselves distasteful) are imitated by species with more innocuous diets. Because the appropriate model for such mimicry may vary with distribution, some mimetic species are quite variable in appearance; prior to the genus' revision by Willmott (2003a), some members of a single species were classified in entirely separate species groups!

REFERENCES

Aiello, A. 1984. Adelpha (Nymphalidae): deception on the wing. Psyche 91 :1-46.

Willmott, K. R. 2003a. The Genus Adelpha: Its systematics, biology and biogeography (Lepidoptera: Nymphalidae: Limenitidini). Scientific Publishers.

Wilmott, K. R. 2003b. Cladistic analysis of the Neotropical butterfly genus Adelpha (Lepidoptera: Nymphalidae), with comments on the subtribal classification of Limenitidini. Systematic Entomology 28: 279-322.

Brine Fairies

The once-ubiquitous 'sea monkey' advertisement. Take a very good look at the words in the lower margin.

Readers of a certain age (or readers who have perused the comic books once belonging to readers of a certain age) will instantly recognise the image above. It appeared on almost every comic book published between 1962 and 1975, and offered a something truly mind-blowing. For a couple of bucks, you could receive a small packet in the post that, when its contents were added to water, grew into minute fish-tailed humanoids that would create their own minute society, all in one goldfish bowl sitting in your bedroom!

As Robin Ince summed up the sea monkey experience in his Bad Book Club: 'This was a lie'. You did receive a small packet in the post, the contents of the packet did hatch out in water, but you did not get the pictured anthropomorphs. What you actually got were these:

The North American brine shrimp Artemia franciscana, photographed by Jean-François Cart.

The 'sea monkeys' became labelled one of childhood's great disappointments, which I call an utter shame. Because I personally would describe them as some of the most elegant crustaceans that I've ever seen.

Brine shrimp and their relatives belong to a group called the Anostraca. The Anostraca, sometimes referred to as fairy shrimps, are a group of a little under three hundred described species. They are generally less than an inch long, though the larger species can grow to several inches. The taxon name basically means 'without a carapace', and this is one of the distinctive features of the group. The body is elongate and, behind the head, is divided into a thorax bearing feathery swimming legs and an abdomen lacking appendages except a terminal pair of uropods. Most species of Anostraca have eleven pairs of swimming legs, though the species Polyartemiella hazeni and Polyartemia forcipata have, respectively, seventeen and nineteen pairs (Weekers et al. 2002). Anostracans have a distinctive slow swimming style, lying on their back. They are found living in ephemeral or hypersaline waters where predatory fish are few or absent; in order to persist in such environments, they produce resistant eggs that are able to survive drying out, hatching when the temporary pool is refilled by the rain.

Conservancy fairy shrimp Branchinecta conservatio, from here.

The phylogeny of Anostraca was investigated by Weekers et al. (2002), who found that they could be divided between two lineages: one including the genera Artemia and Parartemia, which are found in hypersaline waters, and the other containing the remaining freshwater genera. Most members of both lineages are filter-feeders, but some larger members of the freshwater lineage in the genus Branchinecta have become predators. The most favoured prey of these large Branchinecta? Why, smaller Branchinecta! Studied specimens of the predatory Branchinecta raptor would only deign to take other invertebrate prey if their preferred B. mackini was unavailable (Rogers et al. 2006). These predatory Branchinecta are found living in turbid, sediment-filled waters with low visibility, and mostly found their prey by coming into contact with it whilst swimming in the water column. Squeezing water out of a pipette near one would incite it to try and attack the pipette. If unable to find swimming prey, B. raptor would swim down to the sediment bed and stir it up, then attempt to find invertebrates flushed out of hiding.

Streptocephalus torvicornis, photographed by J.R. Casaña & Manolo Ambou Terradez.

The two hypersaline genera have complementary distributions: Parartemia is endemic to Australia while Artemia is found on the remaining continents (though Artemia is now present in some localities in Australia as an introduced taxon). In the past, all Artemia around the world were often treated as a single species, A. salina. However, the existence of a number of geographically distinct lineages has now been established, with these treated as separate species (A. salina proper is found in Europe). Both sexually and parthogenetically reproducing forms of Artemia exist. The parthenogenetic forms are treated as a single species, A. parthenogenetica, and derive from a single Eurasian origin, but are themselves genetically diverse, including diploid, triploid, tetraploid and pentaploid individuals (Triantaphyllidis et al. 1998). Sadly, this new-found taxonomic complexity of Artemia is in some danger of re-simplifying: the international trade in brine shrimp, used mostly as food for fish, is almost entirely based on eggs derived from the Great Salt Lake in Utah. As a result of this trade, the North American species A. franciscana has become introduced, both accidentally and deliberately, to saline waters around the world, and has been found in many localities to be replacing the native brine shrimp.

REFERENCES

Rogers, D. C., D. L. Quinney, J. Weaver & J. Olesen. 2006. A new giant species of predatory fairy shrimp from Idaho, USA (Branchiopoda: Anostraca). Journal of Crustacean Biology 26 (1): 1-12.

Triantaphyllidis, G. V., T. J. Abatzopoulos & P. Sorgeloos. 1998. Review of the biogeography of the genus Artemia (Crustacea, Anostraca). Journal of Biogeography 25: 213-226.

Weekers, P. H. H., G. Murugan,J. R. Vanfleteren, D. Belk, & H. J. Dumont. 2002. Phylogenetic analysis of anostracans (Branchiopoda: Anostraca) inferred from nuclear 18S ribosomal DNA (18S rDNA) sequences. Molecular Phylogenetics and Evolution 25: 535-544.

It's the End of the World as We Know It...

...maybe.

For lo, it did come upon this day that the ICZN did look upon electronic-only publication, and say that it was good. Provided that it met the following requirements:

(1) the published work must be registered with ZooBank prior to publication, with provision in the ZooBank record of a permanent archive in which the the published work will be held,

(2) the published work must include evidence of registration, such as the ZooBank registration number, and

(3) the published work must be associated with either an ISSN or ISBN number, so it must be a formal 'book' or 'journal'.

You can read further details here. As is standard for new ICZN requirements, they are not intended to be retroactive, and online-only names from before the new rules were introduced are still invalid.

I don't think that many people will be surprised by this (while you complain about the cost of prescriptions... Mike Taylor is looking very smug). As I've discussed before, I reluctantly came to accept that electronic publication would have to be allowed after I realised that most non-taxonomists (and many actual taxonomists) were finding it increasingly difficult to distinguish what was 'published' from what was not. So what does this mean in practice?

It became clear at an early date that successful management of electronic publication was going to require registration. In the past, most people were talking about registration of names, but the ICZN has decided to go with registration of the actual publication. This avoids any hiccups such as human error leading to some of the names in a publication being 'published' while others are 'unpublished'. I can see potential complications arising with the requirement that registration happen before publication, but ZooKeys has been publishing articles with ZooBank registration numbers for taxa included for a while now, so it would seem that the requirement is not insurmountable. Of course, there would have been potential problems had the requirement been registration after publication. It should be noted that, even though the published work has to include evidence of registration, there is a certain allowance for error, so long as it is clear that the work has indeed been registered (so, for instance, if a transcript error meant that the wrong registration number was included in the publication, that does not automatically invalidate the publication).

The requirement that the publication has either an ISSN or ISBN number means that names cannot be just published carelessly. If I refer to the features of an unpublished species in a blog post, I will not be accidentally 'publishing' that species and potentially confusing the paper trail (electronic trail, in this case). Note also that, while the ZooBank record of a published work must include the ISSN or ISBN, the work itself doesn't directly have to. So, for instance, the ISSN of a journal does not have to be included in every individual article.

One of the biggest concerns raised about allowing electronic publication is that it will make it even easier for would-be taxonomic 'vandals' to ply their irritating trade. The registration and ISSN/ISBN requirements, as well as making it clear what is intended for publication and what is meant to be just an online communication, are intended to impede such behaviour. They won't stop it entirely (as I've noted a few times before, that would be effectively impossible) but they do provide a couple of hoops that must be jumped through.

So all that remains to be said is: Let the games commence!

The Variety of Life turns 1000

I have just published the 1000th entry onto the Variety of Life site. Subject: the weevil subfamily Baridinae.

I started "The Variety of Life" a bit over a year and a half ago to give a broad, more technical sampler of organismic diversity, and to convey sometime of just how extensive that diversity was. On that note, the main thing that strikes me after 1000 entries of higher-level taxa is just how little of it I've touched on. Perhaps the only group that I wouldn't say is completely rudimentary are the mosses, and even then it's pretty ropey.

Still, I'm reasonably happy with how its progressing, and things can only improve. Already, there are some taxa for which "The Variety of Life" comes out #1 in a Google search. Which, considering the rudimentary coverage I've just spoken of, is more of an indictment of just how poorly covered some taxa are in general.

A Brain Explosion

Elliptical star coral Favia speciosa, photographed by Utsunomiya.
For today's random taxon, I drew the Faviinae. This is a subfamily within the Faviidae, commonly known as 'brain corals' and recognised as an important family among the tropical reef-builders. Families of corals have generally been distinguished by the arrangement and morphology of skeletal structures within the coral cup: Faviidae were characterised by having trabeculae (the calcareous fibres forming the basis of the skeletal septa) arranged in one or two fans, with more or less regular marginal teeth at the top of the septum. The Faviidae were divided into two subfamilies, the Faviinae and Montastreinae, based on whether the budding of polyps takes place inside (Faviinae) or outside (Montastreinae) the individual cups in a colony. Several genera recognised within the Faviinae were mostly distinguished by their colony form and how the individual polyps are arranged (Budd & Stolarski 2011).

Leptoria phrygia, photographed by Neville Coleman.
And if any of you were wondering about the use of the past tense in the last paragraph, that is because more recent studies have been pretty unanimous in indicating that the system just described is in need of a significant shake-up. As noted here in an earlier post, molecular studies have indicated that coral taxa distinguished by septal characters are widely problematic. A broad phylogenetic study of corals by Fukami et al. (2008) found that, of sixteen recognised families tested, eleven were polyphyletic. Faviidae, in particular, were scattered between no less than seven of the twelve supported clades identified by Fukami et al. within the broader 'robust clade'. Some of the larger genera, such as the type genus Favia, were also polyphyletic and dispersed between multiple clades. The level of discordance between morphological classification and molecular phylogeny is reflected by the fact that Fukami et al.'s large clade XVII, containing members of the families Faviidae, Merulinidae and Pectiniidae, has since been informally dubbed the 'Bigmessidae' (Huang et al. 2011). The 'Bigmessidae' also includes the genus Trachyphyllia, a morphologically very variable coral that is generally found free-living, either solitary or colonial, among the sand at the very base of coral reefs (Best & Hoeksema 1987). Trachyphyllia has been treated by some authors as its own family, or regarded by others as an unusual member of the Faviinae.

Maze brain coral Goniastrea australensis, photographed by David Witherall.
As yet, no formal reclassification of the corals has been proposed, but when it eventually is, it is likely that there will be no Faviidae at all. The type species of the family, Favia fragum, is closely related to the type species of another family, Mussidae, and the latter name is the one with priority. Interestingly, both these taxa are found in the Atlantic Ocean, and the molecular phylogenies do support a separation of the Atlantic faviids from the Pacific species. Also, it is still possible that morphological characters will play their part in the coming coral reclassification: even though the broader scale features of the septa and colony form have proven vulnerable to convergence, smaller scale features of the skeletal microstructure promise to be less discordant with molecular phylogenies (Budd & Stolarski 2011).

REFERENCES

Best, M. B., & B. W. Hoeksema. 1987. New observations on scleractinian corals from Indonesia: 1. Free-living species belonging to the Faviina. Zoologische Mededelingen 61 (27): 387-403.

Budd, A. F., & J. Stolarski. 2011. Corallite wall and septal microstructure in scleractinian reef corals: comparison of molecular clades within the family Faviidae. Journal of Morphology 272: 66-88.

Fukami, H., C. A. Chen, A. F. Budd, A. Collins, C. Wallace, Y.-Y. Chuang, C. Chen, C.-F. Dai, K. Iwao, C. Sheppard & N. Knowlton. 2008. Mitochondrial and nuclear genes suggest that stony corals are monophyletic but most families of stony corals are not (order Scleractinia, class Anthozoa, phylum Cnidaria). PLoS ONE 3 (9): e3222.

Huang, D., W. Y. Licuanan, A. H. Baird & H. Fukami. 2011. Cleaning up the ‘Bigmessidae’: molecular phylogeny of scleractinian corals from Faviidae, Merulinidae, Pectiniidae and Trachyphylliidae. BMC Evolutionary Biology 11: 37.