Gagrella

Gagrella amboinensis, copyright Michael Kesl.

Belongs within: Sclerosomatidae.

Gagrella is a diverse genus of sclerosomatid harvestmen recognised from southern Asia and northern Australasia, currently lacking a properly defined diagnosis and hence of uncertain monophyly.

Gnah! Gagrella! Headdesk!
Published 6 June 2008
‘Gagrella’ splendens—is this the face of Evil? Photo by sswroom.

Please permit me to vent some frustration. I’ve written elsewhere about the ghastly legacy left to many areas of harvestman taxonomy by the work in the first half of the 1900s of Carl-Friedrich Roewer, henceforth referred to as the Antichrist of Arachnology, through his use of artificial classification systems and slipshod taxonomy. In the past, I personally have managed to remain relatively unscathed by the dark influence of Roewer, who did not deal much with the Australian opilionidan fauna. In the last few days, this has sadly changed dramatically. I have found myself wandering into the toxic wasteland that is Gagrella.

The Gagrellinae are a sizable subfamily found in tropical and subtropical Asia and the Americas. The centre of diversity for the subfamily is in Asia, whence about 700 species have been described. Many of these species are exceedingly colourful, strikingly ornamented and just downright remarkable. The problem is that most of the Gagrellinae, including Gagrella itself, have not really been revised since Roewer’s massive investigation of the group, culminating in a monograph of the Asian Gagrellinae published in four parts over 1954 and 1955. As with other groups of harvestmen, Roewer used an artificial classification system based on characters such as the numbers of nodules in the legs or spines on the carapace—characters which have sometimes since been shown to not even be consistent between members of the same species, let alone the same genus (there are specimens of other taxa that, if one was to use Roewer’s identification system, the left side of the animal would key out as one genus while the right side would key out as another). It is therefore quite likely that, were a full revision to be conducted, many species would have to be placed in different genera from their current position. With, as I said, about 700 species involved, this would be a mammoth task.

And yet there is a second layer of ghastliness, to make the problem even more difficult. Of the species assigned to Gagrellinae, a little less than 200 have been assigned to the largest genus, Gagrella. The type species of this genus is one Gagrella signata. However, when Roewer worked on the genus, he moved G. signata out of Gagrella and into another genus, Crassicippus, leaving the remaining species as Gagrella. Because the genus name is required to always stay with the type species, this actually meant that what Roewer called Crassicippus should have been called Gagrella, while what he called Gagrella should have been something else! Unfortunately, almost all authors following Roewer used his inaccurate sense of Gagrella, meaning that of those nearly 200 species, none of them actually belong to Gagrella unless they happen by coincidence to have been placed in the wrong genus and are actually closer to G. signata.

Unidentified South American Gagrellinae, congregating suspiciously, photographed by Bruno Buzatto.

Under strict application of the rules of nomenclature, what is now ‘Gagrella’ should actually be called Hexomma, that being the oldest genus name synonymised with Gagrella sensu Roewer in the past (Crawford, 1992). Unfortunately, the name Hexomma has been used as a valid genus in all of about three publications since it was first published back in 1876. Also, there are serious doubts about whether the type species, Hexomma vulcanicum, is actually identifiable. Roewer (1954), who may or may not have seen the type specimens*, claimed it to be based on unidentifiable juveniles, and the type specimen(s) seems to have since gone AWOL (Crawford, 1992).

*Roewer (1954) claims to have examined type specimens that he had borrowed from Vienna, but then eight lines later lists “Holotypus (Thorell) (Mus. Stockholm, Genua?)”. As the Vienna specimens were correctly attributed to Doleschall rather than the later Thorell (albeit from the wrong publication), the Vienna record seems more likely to be accurate. Thorell later redescribed Hexomma vulcanicum as Gagrella vulcanica, and the Stockholm/Genoa specimen listing probably refers to the specimen used by Thorell for the redescription (and so not actually a holotype).

Why does all this matter to me? I am currently trying to write a description of a new species of Gagrellinae. Seeing as I am not in a position to conduct the full revision of the Asian Gagrellinae, my best option for now would be to follow the Roewer classification, despite its faults. Unfortunately, the species keys out to ‘Gagrella’… What am I (or other workers on Asian Gagrellinae) to do about this huge ugly pile of taxonomic blancmange? Among the options:

  1. Move everything currently in Gagrella to Hexomma: Probably not that good an idea, considering that Hexomma is not a well-defined genus and many (if not most) of the species will end up having to be moved out anyway.
  1. Conserve the definition of Gagrella as used by Roewer: One option might be ask the ICZN to conserve Roewer’s usage of Gagrella. Under normal conditions, this would be ideal, but in this case much the same issues apply as with the first option – what’s the point with conserving Gagrella in its current condition if most of the species are probably going to end up having to move anyway?
  1. Run screaming in horror from the entire concept of Asian Gagrellinae and end up crouched into foetal position and whimpering in the darkest recesses of the wet collection: At the moment, this option is looking increasingly attractive…
Score one for biogeography
Published 14 August 2009
Gagrella cauricrepa, the new gagrelline from northern Queensland. Specimen photographed by yours truly (offhand, I think that in over two years, this may be the first time that I’ve used one of my own images on this site. Now you know why).

One morning as I was sitting down to morning tea shortly after I first arrived in Perth, I made the comment that it was very strange that no Gagrellinae had been recorded from Australia*. Species of the subfamily have been described from both New Guinea and the Solomon Islands, so one would expect to find them here as well. New Guinea and Australia were connected in very recent history so, in biogeographic terms, the Torres Strait generally has not functioned as a barrier. Most organisms that are found on one side are also on the other. Why not gagrellines? Yesterday, I had a paper (alluded to in the earlier post) published that solves the mystery by establishing that there is no mystery at all. Gagrella cauricrepa Taylor 2009 is the first species of Gagrellinae described from Australia. Maybe (more on that later).

*I hasten to note that I was at the museum at the time. I’m not normally in the habit of bringing up random enigmas of arthropodological biogeography in mixed company.

Gagrella cauricrepa is found in the Iron Ranges, which are located right near the northern end of the Cape York Peninsula (the pointy bit at the top end of Queensland). The location in the Iron Ranges also offers a neat explanation as to why Australian gagrellines are not more widespread—it is one of the few patches of true wet rainforest in Australia (most of the remaining forest on Cape York Peninsula is drier), so it is probably the shortage of suitable habitat that holds back the gagrelline advance. Torres Strait itself was no barrier at all*.

*Offhand, despite the universal recognition of the biogeographic identity between northern Queensland and southern Papua New Guinea, I found it surprisingly difficult to find supporting references for it. Few people bother to document what they think everybody knows.

Readers of the section above may raise an eyebrow at my placing the new species in the genus Gagrella. All I can say in my defense is that while I know that doing so was a completely stupid, senseless thing to do, all my other options were even more stupid and senseless. The paper does include a discussion of how stupid and senseless I was being.

One thing that you may not realise when reading the paper, on the other hand, is just how close I came to potentially making a prat of myself when writing it (you know, I could have quite easily kept my silence on this subject, but instead I will cheerfully dance for your amusement). My description of the first recorded Australian gagrelline had been submitted, reviewed, revised and was ready to print. Until, only a few days after submitting the final revisions, I was pulling stuff out of Roewer (1910) for the still-in-prep-and-probably-will-be-for-some-time-yet nomenclator, when I saw that Roewer’s (1910) description of the new species Zaleptus marmoratus gave the locality as “Australien?” I had been scooped by some ninety-nine years! That was the reason behind the post on Maison Verreaux, who were the source of the Zaleptus marmoratus type specimen. I had not noticed any other gagrellines from Australia in any of the collections I went through, and as it turned out the reputation of Maison Verreaux for supplying specimens with sloppy if not entirely fabricated locality data means that the origin of Zaleptus marmoratus cannot be accepted unquestioningly. No other species of Zaleptus has been recorded east of Sumatra—even if Roewer’s Zaleptus is not a monophyletic group (which is probably quite likely), I think the absence from the area of species of a ‘zaleptean’ morphology still counts for something in this case.

As explained in the paper, I also wasn’t able to find any indication that Jules Verreaux (the only member of Maison Verreaux to visit Australia) had been far enough north in Queensland to be collecting gagrellines. This conclusion is somewhat more shaky – Jules himself never wrote an account of where he had been (I’m guessing that he probably didn’t want to leave a paper trail), so I was dependent on other people’s records (“Australia” was about as specific as a Verreaux label got). But in concert with the point that Jules’ brother Édouard definitely was in south-east Asia in the early 1830s*, near where ‘Zaleptus‘ species have been reliably recorded, I suspect that an Asian rather than Australian origin for Z. marmoratus is at least possible, if not really demonstrable in the absence of specimens other than the holotype. So while Gagrella cauricrepa may not be the first record of Gagrellinae from Australia, it is the first reliable record from Australia.

*Contrary to what I said in the paper, it seems likely that Édouard travelled in south-east Asia more than Jules. My potted summary of their movements relevant to Z. marmoratus (written rather hastily, so as not to lose the deadline) was drawn heavily from Jules Verreaux’s obituary in The Ibis. Unfortunately (but perhaps fittingly), the Ibis obituary seems to have been misleading about a number of things. In particular, it states that:

In 1832 Jules Verreaux again summoned his brother to join him [in South Africa], and till 1837 they travelled together, making expeditions to the Philippine Islands and Cochin-China. In 1838, having amassed large collections, the brothers shipped their treasures on board the trading-vessel ‘Lucullus’, they themselves embarking in another ship bound for France. Most unfortunately the ‘Lucullus’ was totally lost; and the labours of several years, uninsured, perished with her.

In my paper, I interpreted this to mean that both brothers arrived in Asia in 1832, remained there until 1837, but lost all their Asian material when the ‘Lucullus’ sank (which would be something of a problem for an Asian origin of Z. marmoratus). However, going by other references (see the Maison Verreaux post, which was written later than the Gagrella cauricrepa paper), it seems more likely that one, the other, or both brothers together made a number of trips between Asia, Paris and/or South Africa between 1832 and 1837, and that when Jules Verreaux was returning to Paris with material shipped on the ‘Lucullus’, he was returning from South Africa, not Asia (frustratingly, I haven’t been able to find anything that says exactly where the ‘Lucullus’ had left from). It says something about the difficulty of tracing a person when you can’t even be certain what continent they were on.

Systematics of Gagrella

Characters (from Martens 1987): Femur II only with a single pseudoarticular nodule; area 2 or areas 1 and 2 of scutum each with a median cone; eyemound low, smooth or granular, without large spines; femora I and III cylindrical, longer than body.

<==Gagrella Stoliczka 1869T09 [incl. Crassicippus Roewer 1910C92]
    |--*G. signata Stoliczka 1869T09 [=Crassicippus signatusB30]
    |--G. aenescens Thorell 1889S85
    |--G. aenigra Roewer 1954R54
    |--G. alba Suzuki 1985S85
    |--G. albertisii Thorell 1876T09 (see below for synonymy)
    |--G. albicoxata Roewer 1954R54
    |--G. albifrons Roewer 1915R54
    |--G. albipunctata Suzuki 1977S77a
    |--G. amboinensis (Doleschall 1857)T09 [=Phalangium amboinenseC92; incl. Gagrella mediocris Kulczynski 1910R23]
    |    |--G. a. amboinensisT09
    |    `--G. a. bicornuta Strand 1910T09
    |--G. andamana Roewer 1929R54
    |--G. annapurnica Martens 1987M87
    |--G. annulatipes Roewer 1912R54
    |--G. aorana Roewer 1954R54
    |--G. apoensis Suzuki 1977S77a
    |--G. argentea Roewer 1913R54
    |--G. armillata Thorell 1889R54
    |--G. atrorubra Simon 1901R54
    |--G. aura (Rainbow 1913)T09 [=Liobunum aurumR23]
    |--G. aureolata Roewer 1915R54
    |--G. aurispina Roewer 1954R54
    |--G. auromaculata Roewer 1954R54
    |--G. auroscutata Roewer 1954R54
    |--G. bakeri Roewer 1926R54
    |--G. beauforti Roewer 1913R54
    |--G. bella Roewer 1954R54
    |--G. bengalica Roewer 1954R54
    |--G. biarmata Roewer 1954R54
    |--G. bicolorispina Roewer 1954R54
    |--G. binotata Simon 1887R54
    |--G. biseriata Simon 1901R54 [incl. G. illusa Simon 1902R23]
    |--G. borneoensis Roewer 1954R54
    |--G. brunnea Roewer 1954R54
    |--G. buruana Roewer 1954R54
    |--G. caerulea Roewer 1910R54
    |--G. cana Roewer 1954S85
    |--G. carinia Roewer 1936R54
    |--G. cauricrepa Taylor 2009T09
    |--G. ceramensis Roewer 1913R54
    |    |--G. c. ceramensisR54
    |    `--G. c. ‘bispinosa’ Roewer 1913 non G. feae bispinosa Thorell 1889R54
    |--G. cerata Roewer 1913R54
    |--G. cervina Simon 1887R54
    |--G. cinerascens Roewer 1910R54
    |--G. concinna Thorell 1891R54
    |--G. coriacea Roewer 1910S85
    |--G. corrugata Roewer 1954R54
    |--G. crassitarsis Suzuki 1969S85
    |--G. cruciata Roewer 1923R54
    |--G. cuprea Roewer 1910R54
    |--G. cuprinitens Roewer 1954R54
    |--G. curvispina Roewer 1913R54
    |--G. cyanargentea Roewer 1915S85
    |--G. cyanatra Roewer 1954R54
    |--G. delicatula Roewer 1954R54
    |--G. denticulatifrons Roewer 1954T09
    |--G. disticta Thorell 1889S85 [=G. nocticolor var. distictaR23]
    |--G. docilisW03
    |--G. dubia Giltay 1930T09
    |--G. duplex Roewer 1915T09
    |--G. elegans Simon 1877R54
    |--G. ephippiata Thorell 1891 [=Crassicippus ephippiatus]R23
    |--G. erebea Thorell 1889R54
    |--‘Crassicippus’ figuratus Roewer 1923R23
    |--G. flava Roewer 1910R54
    |--G. flavimaculata With 1903R54
    |--G. fokiensis Roewer 1954R54
    |--G. foveolata Roewer 1923R54
    |--G. franzi Martens 1987M87
    |--G. fulva Roewer 1910S85
    |--G. fumosa Suzuki 1985S85
    |--G. fuscipes Roewer 1910T09
    |--G. gilva Roewer 1926R54
    |--G. grandis Roewer 1910R54
    |--G. granobunus Roewer 1954T09
    |--G. gravelyi Roewer 1912R54
    |--G. grisea Roewer 1911R54
    |--G. hainanensis Roewer 1911R54
    |--G. hasseltii Thorell 1891R54
    |--G. heinrichi Roewer 1954R54
    |--G. histrionica Thorell 1889R54
    |--G. indochinensis Roewer 1927R54
    |--G. infuscata Roewer 1911R54
    |--G. insculpta Pocock 1897R54 [=Hexomma insculptaB30]
    |--G. insulana Roewer 1954R54
    |--G. iwamasai Suzuki 1977S77b
    |--G. lateritia Roewer 1954R54
    |--G. leopoldi Giltay 1930T09
    |--G. lepida Thorell 1889S85
    |    |--G. l. lepidaR54
    |    |--G. l. claducha Thorell 1889R54
    |    `--G. l. dibelona Thorell 1889R54
    |--G. leucobunus Roewer 1912R54
    |--G. lineatipes Roewer 1911R54
    |--G. longipalpis Thorell 1891R54 [=Hexomma longipalpisB30]
    |--G. longipes Suzuki 1982S85
    |--G. longispina Roewer 1913R54
    |--G. luteofrontalis Roewer 1910S85
    |--G. luzonica Loman 1902R54
    |--G. magnifica Roewer 1910R54
    |--G. malabarica Roewer 1954R54
    |--G. malkini Suzuki 1977S77a
    |--G. marginata Roewer 1954R54
    |--G. melanobunus Suzuki 1977S77a
    |--G. mertoni Strand 1911R54
    |--G. metallica Roewer 1929R54
    |--G. mindanaoensis Suzuki 1977S77a
    |--G. minuta Roewer 1954R54
    |--G. mjobergi (Banks 1930) [=Hexomma mjobergi]R54
    |--G. modesta Suzuki 1985S85
    |--G. monacantha (Herbst 1798) (n. d.) [=Opilio monacantha, Phalangium monacanthum]R23
    |--G. monticola Thorell 1891R54
    |    |--G. m. monticolaR54
    |    `--G. m. tarda Thorell 1891R54
    |--G. natuna Roewer 1912R54
    |--G. neocera Forster 1949T09
    |--‘Crassicippus’ nigerrimus Roewer 1910R23
    |--G. nigrescens Roewer 1954R54
    |--G. nigripalpis Roewer 1910R54
    |--G. niponica Roewer 1954R54
    |--G. nobilis With 1903R54
    |--G. nocticolor Thorell 1889 (n. d.)R23
    |--G. obscura Simon 1877R54
    |--G. ochroleuca Roewer 1954R54
    |--G. opaca Roewer 1954R54
    |--G. ornata Roewer 1910R54
    |--G. palawanica Suzuki 1977S77a
    |--G. palnica Roewer 1929R54
    |--G. parallela Roewer 1931R54
    |--G. parva Roewer 1929R54
    |--G. patalungensis Simon 1901R54
    |--G. pauper With 1905KM20 [=G. pauperaKM20, Eugagrella pauperaR23]
    |--G. prasina Roewer 1911R54
    |--G. pretiosa (Banks 1930) [=Hexomma pretiosa]R54
    |--G. promeana Roewer 1954T09
    |--G. pulcra Suzuki 1985S85
    |--G. pullata Thorell 1891S85
    |--G. punctata Roewer 1954R54
    |--G. quadrimaculata Roewer 1954S85
    |--G. quadriseriata Roewer 1954R54
    |--G. quadrivittata Simon 1887 [=Crassicippus quadrivittatus]R23
    |--G. reticulata Suzuki 1977S77a
    |--G. rorida Roewer 1954R54
    |--G. rufa Roewer 1954R54
    |--G. sadona Roewer 1954R54
    |--G. sampitia Roewer 1954R54
    |--G. sarasinorum Roewer 1913R54
    |--G. sarawakensis With 1905R54 [=Hexomma sarawakensisB30]
    |--G. satarana Roewer 1954R54
    |--G. scabra Roewer 1912R54
    |--G. scintillans Roewer 1910R54
    |--G. scrobiculata Thorell 1891R54 [=Hexomma scrobiculataB30]
    |--G. scutaurea Roewer 1954R54
    |--G. semangkokensis Suzuki 1972S72
    |--G. semigranosa Simon 1901 [=*Crassicippus semigranosus]C92
    |--G. serrulata Roewer 1910R54
    |--G. sexmaculata Suzuki 1969S85
    |--G. sherriffsi Roewer 1954R54
    |--G. similis Suzuki 1977S77a
    |--G. sinensis Roewer 1954R54
    |--G. speciosa Roewer 1911R54
    |--‘Crassicippus speciosus’ Roewer 1912 non Gagrella speciosa Roewer 1911R23
    |--G. spinoculata Roewer 1931R54
    |--G. spinulosa Thorell 1889S85
    |--G. subfusca Roewer 1910R54
    |--G. sulphurea Roewer 1912S85
    |--G. suluana Roewer 1954R54
    |--G. sumba Roewer 1954R54
    |--G. tenuipalpis Suzuki 1977S77a
    |--G. testacea Roewer 1954 non Phalangium testaceum Doleschall 1859 (not preoc. if dif. gen.)R54
    |--G. thaiensis Suzuki 1982S85
    |--G. thorelli (Banks 1930) [=Hexomma thorelli]R54
    |--G. tibialis Roewer 1931S85
    |--G. tinjurae Martens 1987M87
    |--G. tricolor Roewer 1954R54
    |--G. tuberculata Roewer 1913R54
    |--G. turki Roewer 1954R54
    |--G. unispinosa With 1903R54 [=G. imperator unispinosaR23]
    |--G. victoria Roewer 1954R54
    |--G. viridalba Roewer 1954R54
    |--G. viridargentea Roewer 1954R54
    |--G. viridula Roewer 1929R54
    |--G. werneri Suzuki 1977S77a
    `--G. yodoensis Roewer 1954R54

Gagrella albertisii Thorell 1876T09 [incl. G. aruella Strand 1911R23, G. bipeltata Thorell 1891R23, G. doleschallii Thorell 1876R23, G. bipeltata var. inquirenda Strand 1910S10, R23, G. samangana Strand 1911R23, G. xanthostoma Thorell 1891R23]

*Type species of generic name indicated

References

[B30] Banks, N. 1930. Phalangida from Borneo. Sarawak Museum Journal, new series 4 (1): 57–86, pls 11–12.

[C92] Crawford, R. L. 1992. Catalogue of the genera and type species of the harvestman superfamily Phalangioidea (Arachnida). Burke Museum Contributions in Anthropology and Natural History 8: 1–60.

[KM20] Kury, A. B., A. C. Mendes, L. Cardoso, M. S. Kury & A. A. Granado. 2020. WCO-Lite: Online world catalogue of harvestmen (Arachnida, Opiliones). Version 1.0—Checklist of all valid nomina in Opiliones with authors and dates of publication up to 2018. Published by the author: Rio de Janeiro.

[M87] Martens, J. 1987. Opiliones aus dem Nepal-Himalaya. VI. Gagrellinae (Arachnida: Phalangiidae). Courier Forschungsinstitut Senckenberg 93: 87–202.

[R23] Roewer, C.-F. 1923. Die Weberknechte der Erde: Systematische Bearbeitung der bisher bekannnten Opiliones. Gustav Fischer: Jena.

[R54] Roewer, C. F. 1954. Indoaustralische Gagrellinae (Opiliones, Arachnidae). (Weitere Weberknechte XVIII). 1. Teil. Senckenbergiana Biologica 35 (3–4): 181–236.

[S10] Strand, E. 1910. Spinnentiere aus Neuguinea (Opiliones, Psechridae und Clubionidae) gesammelt von Dr. Schlaginhaufen. Abhandlungen und Berichte des Königl. Zoologischen und Anthropologisch-Ethnographischen Museums zu Dresden 13 (5): 1–16.

[S72] Suzuki, S. 1972. Opiliones of Semangkok Forest Reserve, Malaysia. Journal of Science of the Hiroshima University, Series B, Division 1 (Zoology) 24 (1): 1–37.

[S77a] Suzuki, S. 1977a. Report on a collection of opilionids from the Phillippines. Journal of Science of the Hiroshima University, Series B, Division 1 (Zoology) 27 (1): 1–120.

[S77b] Suzuki, S. 1977b. Opiliones from Taiwan (Arachnida). Journal of Science of the Hiroshima University, Series B, Division 1 (Zoology) 27 (1): 121–157.

[S85] Suzuki, S. 1985. A synopsis of the Opiliones of Thailand (Arachnida) II. Palpatores. Steenstrupia 11 (7): 209–257.

[T09] Taylor, C. K. 2009. Revision of the Australian Gagrellinae (Arachnida: Opiliones: Sclerosomatidae), with a description of a new species. Australian Journal of Entomology 48: 217–222.

[W03] With, C. 1903. New and old Phalangiidae from the Indian region. Journal of the Linnean Society, Zoology 28: 466–509.

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