Painless mites

My freezers at work are getting rather full, so I’ve been washing birds and sending the clean bodies to the Royal Alberta Museum. Last week I washed a batch of white-throated sparrows (Zonotrichia albicollis) that had met a sad communal death by flying into a window in Edmonton. They were very mite-rich, providing dozens of specimens of Proctophyllodes (Proctophyllodidae), Mesalgoides (Psoroptoididae), and Analges (Analgidae).  All of these taxa belong to the feather mite superfamily Analgoidea. Analges means “without pain”, and the genus was called thusly by Nitzsch in 1818 because it seemed that even heavily laden birds showed no signs of distress. Almost two hundred years later, a huge comparative study by Ismael Galván and colleagues in 2012 compared feather mite load and host condition of 83 species of birds and found no evidence of a negative relationship. Feather mites in general appear to be harmless commensals of their hosts.

Analges species are interesting because of their striking male polymorphism. All males differ from females in having enlarged third legs with spear-like tarsal claws, but legs of some individuals are much more grotesquely hypertrophied than others. Such males are also larger overall.

Analges sp. mites from white-throated sparrows from Edmonton, Alberta. From left to right: female, homeomorphic male, heteromorphic male (all to the same scale).

Male polymorphism is very common in feather mites and many other Astigmata. The less elaborated male forms are typically called ‘homeomorphs’ and the extravagant ones ‘heteromorphs’ (the reason for the terms being that the former are more similar to females than the latter).

But what are the modified third legs used for? Holding females? Stabbing rival males? I’m not sure that anyone knows.

Legs of homeomorphic (left) and heteromorphic (right) male Analges. The pointy tarsal claws look nasty.

 

 

 

 

Tasty Trivia from Almonds to Yeast

Lectures for this semester are done, exams have been endured, and all that’s left is grade assignment. That and a feeling of regret that much of the cool trivia I picked out from Harold McGee’s “On Food and Cooking” (2004) to incorporate in my intro biology lectures went unused.  So I thought, why not share them in a blog post? They are timely, given the seasonal focus on food. Here are some of my favourite biological revelations in order of their appearance in the book.

p. 505 – almonds are among the most oil-rich of nuts (54% oil, see Table on p. 502), and a faux ‘milk’ can be made by soaking the nuts in water and grinding to release tiny oil bodies, together with proteins and sugars. Almond milk is not a new creation, as it was known in Medieval Europe, and used in Arabian cooking before then.

p. 506 – Brazil nuts have nutrients stored in embryonic stems rather than in embryonic leaves. They are even oilier than almonds at 67% oil, and hence are very calorie-rich. They have the highest level of selenium of any food known and too many can be toxic (maximum recommended daily intake for adult humans = 14 g)

p. 507 – the cashew is a relative of poison ivy, hence we never see cashew nuts for sale in the shell.

p. 509 – ginkgo seeds are edible and mild in flavour even if the flesh of the ‘fruit’ is stinky.

p. 510 – there are two other nuts that beat out almond and Brazil nuts re. oil. Macadamias have 72% oil and nuts of some Asian pines have 78%.

p. 512 – pistachios are green because their cotyledons contain chlorophyll.

p. 513 – poppy seeds contain enough opium-associated alkaloids to make one’s urine test positive for drugs, even though they don’t cause other pharmacological effects. It takes 2-4 million poppy seeds to make a kilogram.

p. 517 – yeast causing dough-rising was initially ‘wild’ and accidental, but by 300 BC there is evidence of a special profession of yeast-making for bread in Egypt (probably as a by-product of beer making).

p. 519 – baking soda and baking powder weren’t invented until 1830 and 1850, respectively.

p. 545 – pumpernickel = ‘devil’s farts’. See also below.

p. 552 – the name of a type of puff pastry, pets de nonne, means ‘nun’s farts’.

p. 609 – Agar-agar is a Malay term. It refers to a mixture of carbohydrates from several genera of red algae. To make it, the algae is boiled and the liquid filtered and freeze-dried. Agar forms a gel at even lower concentrations than does gelatin (<1% by weight). Few bacteria can digest agar and it stays solid at room temperature, so it’s a good medium for growing microbes (which can be fed with nutrients added to the agar).

p. 610 – carageenan, used in ice cream and toothpaste among other things, comes from the red alga Chondrus crispus and a few other species.

p. 647 – the names Melissa and Deborah both mean ‘bee’.

p. 647 – a quote from Pliny indicates that he thought the source of honey to be ‘star saliva’.

p. 648 – sugar cane may have first been domesticated in New Guinea; however, the first people to refine sugar from cane were in India around 500-350 BC. The word ‘sugar’ comes to English from Arabic via Sanskrit.

p. 651 – discovery of how to extract sugar from beets (Beta vulgaris var. altissima) in 1747 was a major cause of the decline of slavery in the West Indies (an economic rather than a moral reason to stop using expensive human labour); however, beet sugar didn’t really take off until the 1810’s. Beet sugar currently = ~30% of world sucrose production (p. 652).

p. 663 – honey made from nectar of particular species of Rhododendron is ok for bees but affects lungs and hearts of humans.

p. 668 – maple syrup is usually made by boiling off water from sap, but can also be made (as done by some native North Americans) by allowing the water to freeze then removing the upper skim of ice repeatedly.

p. 669 – can also make a sweet syrup from birch sap, but it is a much more dilute sap than that from sugar maple (about 1/3 the concentration).

p. 670 – the Asian sugar palm (Borassus flabellifer) has much sweeter sap than sugar maple, up to 12% sucrose compared to maple’s 3%. Crystallized palm sugar is called jaggery in English, from Sanskrit sharkara.

p. 670 – ‘sugarloaf‘ as a term referring to, e.g., the shape of a mountain, comes from the use of a mould shaped like a truncated inverted cone with a hole in the bottom to drain molasses from cane sugar.

p. 677 – corn syrup is actually made from corn starch that is broken down into glucose using acids and/or enzymes. The most common enzymes today come from Aspergillus. High-fructose corn syrup is made by converting some of the glucose into fructose via other enzymes. Retention of some larger carbohydrate molecules makes corn syrup viscous.

Many things to think about when making or enjoying Christmas fruitcake (and yes, I do like fruitcake even though most of the world seems to disparage it).

Snipe hunt

This afternoon one of my colleagues passed on the good news that he had just put a roadkilled charadriiform in the Museum of Zoology’s freezer. I don’t have a lot of mites from Albertan charadriiforms, so I was eager to see get the bird and wash it. The body turned out to be that of a Wilson’s Snipe, currently Gallinago delicata Ord in most taxonomies, though not all feel that it deserved having been raised from its previous subspecies status (G. gallinago delicata).

It was a lovely specimen and I took it to show to people in the main office. “It’s pretty rare to come back from a snipe hunt with an actual snipe!” I said, attempting to be amusing. Two people laughed, and two just stared. “You know what a ‘snipe hunt‘ is, right?” I asked the latter. Nope. When I explained, they got the concept immediately, and came up with other examples (e.g., an apprentice carpenter being sent for a ‘board stretcher’). I wonder if there is an unrecognized linguistic divide in Canada, with snipe-hunting being common in only some regions.

A snipe in the hand. I washed it after taking the photo and was rewarded with a small number of feather mites and lice.

Cheese, soldiers, mites and mice

I’m reading “On Food and Cooking: the Science and Lore of the Kitchen“, a most absorbing book by Harold McGee. A while ago I finished the section on cheese. Among other fascinating tidbits, I learned that the crunchy crystals one sometimes encounters when eating cheese consist of calcium phosphate, calcium lactate, or the amino acid tyrosine. The Greek root ‘tyros’ means ‘cheese’, which suggests that tyrosine may first have been isolated from cheese (a hypothesis supported by Wikipedia). It also made me think of Tyrophagus putrescentiae (= rotting cheese-eater), a widely distributed mite pest of stored products and arthropod cultures that can rapidly go from a few individuals to a pulsing hairy carpet of thousands.

A small subset of the hordes of Tyrophagus putrescentiae that overflowed from my tenebrionid culture.

A related ‘tyro’ mite is Tyrolichus casei, which is employed to make the unusual cheese Milbenkäse. But I also knew that ‘tyro’ referred to a raw novice, particularly a young soldier.  Did the ancient Greeks feed their new recruits on cheese? Off to the OED in search of an answer.  To my surprise, ‘tyro’ wasn’t defined under the common spelling, but rather under ‘tiro’, Latin for young soldier.  No mention of cheese, but also no etymology provided. Off to Google in search of a more complete answer. No agreement that I could find, but plenty of contention.

Even more recently, including yesterday, I employed cheese to capture some of the numerous mice (Mus musculus) that occupy the house, despite the presence of my cat Fred.  Or maybe because of my cat; I’ve seen mice march boldly up to to the catfood bowl and steal kibble from it as Fred watched complacently. Snap traps baited with Swiss cheese do a much better job of mouse control. As an acarologist interested in symbiotic mites, I of course have washed some of the mouse bodies. From the washings I picked out a few tiny fur mites.  They have impressively powerful claws on their first legs.

One of the fur mites from my mouse washings.

My first assumption was that they were Myobia murismusculi (Prostigmata: Myobiidae). But this site says that M. murismusculi (a.k.a. M. muris) has only one claw on its second pair of legs. This individual clearly has two claws, which would make it a Radfordia. The claws seem to be equal in length, leading me to conclude that it is R. ensifera (illustrated here; unequal claws mean R. affinis). All three species are known from Mus musculus. It would be interesting to map the distribution and diversity of fur mites on house mice in Alberta, as one would predict that in longer-settled areas (e.g., old parts of Edmonton), the mice would have a greater number of mite species than in areas recently colonized by a potentially small number of founders.

The Accidental Taxonomist

Dr. Thelma Finlayson, an emeritus professor at Simon Fraser University, will soon be celebrating her 100th birthday. In honour of this event, a half-day symposium was held at FSU a couple of weeks ago. The themes reflected Finlayson’s own research: insect biocontrol and taxonomy. I had been asked by the coordinator of the event, Dr. Elizabeth Elle, to give the final lecture in the symposium with a focus on biodiversity and systematics.  An honour, but also daunting! According to Elle, Finlayson became a parasitoid taxonomist by necessity rather than by original intent. Her main interest was biocontrol but in order to do that she had to become an expert in the taxonomy of tiny wasps. That story made me reflect on my own path to becoming a mite taxonomist.  I, too, had followed an accidental route, with my original interests being ecology and behaviour. Then I wondered how many of my colleagues were also Accidental Taxonomists.

About a month before the symposium I sent a request to three arthropod oriented listservs with different audiences: mite biologists, arachnologists working on taxa other than mites, and parasitoid hymenopterists.  This is the content of that request:

Dear XXX people: I will be giving a presentation on taxonomy at Simon Fraser University at the end of March, and as part of my seminar I would like to discuss how people end up being taxonomists.  In some cases, becoming an expert on the taxonomy of a group may have been a deliberate choice, e.g., as your M.Sc. project you may have chosen to revise a particular genus of XXX.  But in other cases one may have planned to do a project on behaviour or ecology, and discovered that you couldn’t complete the project without first learning the taxonomy of the group.   So, I would greatly appreciate hearing from those of you who have become local (or international!) experts in taxonomy of particular groups of XXX.  Here are my two questions: (1) for what xxx group(s) have you become a taxonomic expert? By ‘expert’, I mean expert at identification, not necessarily someone who also describes new taxa. (2) how did you happen to become an expert? Was that your first choice, or had you originally planned to work on some other aspect of that group’s biology? Many thanks! Heather Here are the results that I presented to a wonderful audience of Finlayson fans on 25 March. (1) Geographical distribution of respondents: 64 people from 23 countries, top five being U.S.A., United Kingdom, Australia, Canada and the Netherlands (see map below). (2) Here are the taxonomic orientations of those respondents:   (3) Out of curiosity, I checked the sex-ratio of the respondents. Strongly male-biased – but note the caveat (which is relevant to ALL of the responses, not just this one). (4) And then the main question: how many respondents became taxonomists deliberately, as their first choice, or by accident or necessity? A few people didn’t answer this question directly, so I made an educated guess based on the stories associated with their responses. The answer is that about half of them were Accidental Taxonomists. (5) My gut feeling after reading the responses was that non-mite arachnologists were much more likely to have chosen taxonomy as a career than were acarologists.  Araneologists seem to be born rather than made.  My guts were correct! One could also hypothesize, conversely, that mite biologists tend to be forced into taxonomy out of necessity, given the vast unknown that is acarine biodiversity. Although some taxonomists responded in a brief and businesslike manner, others provided long and delightful (or sometimes sad) stories of how their scientific careers had evolved.  After the symposium, a few people asked me whether I planned to publish the results.  Nope – can’t.  Didn’t have Human Ethics clearance to do this survey. It is totally illegal, contraband data.  Plus, the survey was not at all scientifically designed. So please take these results cum grano salis.

Souvenirs

A few days ago we made it safely back to Canada after a month of collecting arachnids in Mexico.  While there we couldn’t resist picking up a few other souvenirs in addition to salticids and opilioacarids. One was a bottle of raicilla from the beautiful 400 year old town of San Sebastian del Oeste. Like tequila, raicilla is a distilled liquor made from agave, albeit from a different species in the same genus. The name may mean ‘little root’ but we’re guessing. Selling of raicilla has only recently been legalized according to this site.

Raicilla and opilioacarids safe in Vancouver.

Therefore, I was legitimately able to bring in a bottle as a souvenir, along with my likewise legal container of opilioacarid mites (see permit above!). Unfortunately, the raicilla leaked a bit in my luggage, imbuing my trousers with a smoky flavour.

I also brought back some unintended mementos: clusters of itchy, supporating sores on my ankles resulting from bites of larval mites of the family Trombiculidae (Acari: Parasitengona). Trombiculids are known as chiggers in North America and scrub itch mites in Australia. As larvae, chiggers are parasites of vertebrates while as nymphs and adults they are free-living predators.  Despite common belief, chiggers do not burrow under your skin. Rather, those that bite humans usually attach only briefly and then drop off, leaving behind an itchy wad of spit that continues to cause irritation long after the wee mites are gone.

My right ankle with chigger bites.

Etymological deer-stalking

Skull of a white-tailed deer from UNAM Chamela collection.

Earlier this year my friend John Acorn was frustrated by the genus name for white-tailed and mule deer: Odocoileus.  Greek and Latin dictionaries didn’t help to make sense of it, no matter how potential roots were parsed. He enlisted me and Selina Stewart, a professor of classics at the University of Alberta, in the hunt for the origin of this name.  It was an exciting few hours of Googling!  Many emails were exchanged as we followed blind leads, downloaded uninformative pdfs, and speculated wildly. Then, by chance, I thought to look up where the description of the type species of Odocoileus was published, with the hope that the author of the genus had actually explained his rationale for choosing the name. To my surprise, neither O. virginianus nor O. hemionus – the only two extant members of the genus – turned out to be the type species.  Instead, it was a deer I’d never heard of: Odocoileus speleus.  A cave-dwelling deer? What could this mean? The author was C.S. Rafinesque, and the description was published in The Atlantic Journal, and Friend of Knowledge, Vol. 1, in 1832.

Rafinesque lived from 1783-1840 and had quite a diverse career, dabbling in zoology, botany, geology and Mesoamerican linguistics. He named many species of plants and animals in addition to cervids. Wikipedia calls Rafinesque a polymath, but he didn’t excel in all endeavours. For one thing, his stint as the botanist at Transylvania University in Kentucky ended badly after he had an affair with the wife of the university’s president. For another, he was quite careless with his spelling. This explains Odocoileus. The genus is based on a fossil (or possibly subfossil) tooth found in a cave – hence speleus. Rafinesque had intended the generic name of the tooth’s owner, which he thought might be a type of pig, to refer to the tooth’s hollowness (see excerpt below).  But rather than Odontocoelus, which would have matched his intent well, he wrote the jumbled name that still stands today. There were two attempts at the beginning of the 1900’s to emend the spelling to something more etymologically, but these were deemed unjustified.

That spelling was a persistent challenge for Rafinesque is evidenced by his naming a population of  white-tailed deer Corvus macrourus.

Daddy-longlegs-like mites

Anystis offered a challenging etymological quest (see previous post) but sometimes a spade is just called a spade. I came to the UNAM Chamela field station in Jalisco, Mexico, to hunt for a mite whose lifestyle is mysterious but whose name is straightforward. Mites of the suborder Opilioacarida were once thought to be the most ancient lineage of Acari because they bear remnants of abdominal segmentation and have a strange combination of morphological features of the two main groups mites, the Parasitiformes and the Acariformes, suggesting that opilioacarids may have arisen prior to the split between these two lineages.  However, molecular data don’t support this story, as they place Opilioacarida firmly in the Parasitiformes, and the Acariformes way the heck far off in another part of the arachnid phylogeny (i.e., mites appear to be diphyletic).

Nevertheless, opilioacarids remain very odd parasitiforms, with their big eyes, soft bodies, and gut contents that include particles (most other parasitiforms are blind, crunchy, fluid-feeders).  Their semi-segmented opisthosomas and long gangly legs make them look like a cross between a daddy-longlegs (Opiliones) and mites, hence their name. We don’t know how they catch their food or how they have sex.  My mission in coming to Chamela is to collect live opilioacarids and watch them eat and (fingers crossed) transfer sperm.  But after a week here, I hadn’t even managed to extract a single specimen from the soil, litter, wood and bark that I’ve been putting through my Tullgren funnels.  Until today – I extracted three lovely Neocarus from an unprepossessing habitat consisting of dry soil, scattered small rocks, and crispy leaf litter.  Unfortunately, these three are dead, having fallen into the ethanol at the bottom of the funnels, and hence will not be useful subjects for behavioural observations.  But at least I now know they’re here.

First opilioacarid and habitat nr Jose Maria Morelos

Why ‘Anystis’?

The name for this blog came to me while driving with Wayne Maddison from Puerto Vallarta to the UNAM field station in Chamela, Mexico. We were discussing the pros and cons of social media, and Wayne convinced me that I should try my hand at blogging.  But what to call this maiden attempt? I had been impressed by the interest-piquing obscurity of The Subulate Palpomere as a title and decided to try to emulate it with an acarine rather than coleopteran theme.  Thus arose The Inquisitive Anystid.  And simultaneously, the urge to find out the origin of the name Anystis, which is the type genus for the family Anystidae.  I enlisted the aid of several fellow mite biologists, and within about 24 hours of competitive name-hunting, Dave Walter came up with the strongest hypothesis for what the author of Anystis was thinking about when he named the genus.  You can read about it here on Dave’s Macromite blog.