Redescription Of Nothobrya Schubarti Arle, 1961 (Collembola, Entomobryomorpha)

2004·1.5 MB·English

by  E Baquero

Vol. 115. No. 1.January& February 2004 3J_
REDESCRIPTION OF NOTHOBRYA SCHUBARTI
ARLE, 1961 (COLLEMBOLA, ENTOMOBRYOMORPHA)1
Enrique Baquero2, RafaelJordana2,and Kenneth Christiansen1
ABSTRACT: ThreeparatypesofNothohryasclnihartiArle, 1961 wereexaminedinconnectionwith
aforthcoming descriptionofanewgenusofEntomobryidae. SomeofthefeaturesobservedbyArle
in 1961,appearedsimilartothoseofthenewgenus.These included: small size, color, thepresence
ofPAO,afalciformmucro,thetrochanteralorganandthebodysetae.Observationofaspecimenwith
SEM allowed us to seethe PAO and the othercharacteristics described byArle in more detail, but
other features not described by him were seen which indicate that the genus belongs in subfamily
Orchesellinae.
KEYWORDS: Collembola,Nothobiya, Orchesellinae, Entomobryomorpha.
Arle (1961) describedthe genusNothobiyaofthe family Entomobryidae from
Brazil which was characterized by a lack ofscales, presence ofa postantennal
organ, and a falcate mucro. Although the genus was placed with other Ento-
mobryidae, its taxonomic placement has remained unclear and no subsequent
records ofthe genus have been made. Barra (1999) examined type specimens of
Nothobiya and clearly showed it to be distinct from his genus Capbtya. Due to
the kindness of Dr. Cleide de Mendonca (Museu Nacional, Departamento de
Entomologia, Universidade Federal do Rio de Janeiro, Brazil) we were able to
examine three paratypes of this unusual species and clearly establish that the
genus belongs in the subfamily Orchesellinae ofthe family Entomobryidae.
METHODS
The specimens were preserved in ethyl alcohol, apparently in good condition
(Fig. 1), but they were very fragile. One specimen was mounted on slide using
Hoyer's medium; another, without cleaning due to its fragility, was dehydrated
using an ethanol series followed by critical-point drying in CO2, mounted on an
aluminium SEM stub, and coated inArgon atmosphere with 16 nm ofgold in an
Emitech K550 sputter-coater. SEM observations were made in a Zeiss DSM
940Awith a new digital image capture (Point Electronic GmbH, Germany). Al-
though the animal is much wrinkled, the photographs have been included in this
paper since they are informative. Some characteristics observed under both the
light microscope and SEM are added to Arle's 1961 description.
1 Receivedon May 19, 2004.Acceptedon May21,2004.
: DepartmentofZoology and Ecology, University ofNavarra, P.O. Box 177, 31080 Pamplona, Na-
varra, Spain. E-mail: [email protected].
'Correspondingauthor: Grinnell College, Grinncll \.\ 50112 USA. E-mail: christak(agrinnell.edu.
Mailedon November 12,2004
32 ENTOMOLOGICALNEWS
Genus NothobryaArle, 1961
Diagnosis: The genus differs from other scaleless Orchesellinae by a combina-
tion offalcate mucro, postantennal organ and curved hook-like labral papillae.
Nothobrya schubartiArle, 1961
(Figs. 1-8)
Body length: Excluding appendages: 1.5-2.0 mm (according to Arle), 0.95 mm and 1.16 mm
respectivelyfortheslidemountedandtheethylalcoholpreservedspecimenswestudied.
Color: Groundcolorofbodypaleyellow, with bluepigmentondistal part ofantennal segmentI,
final halfofantennal segments II-III, distaltwothirdsofantennal segment IV, andbandsontheante-
riorhalfofall tergites,coxaeandtrochanters(Fig. 1).
Cuticle: BodyseenunderSEMwithdensereticularpattern(Fig. 7). Scalesabsent.
Head:Antennaesixsegmentedwithboththefirstandthirdsegmentsverysmall(Figs.2-3).Length
inmmofsegments 1-6: 0.02:0.05:0.01:0.09:0.12:0.17respectively. Ommatidia8+8, finelyreticulated
withAand B largerthantheothers. PAOisavesicle(15x5 micrometers),narrowedin itsinnerside,
situatedinfrontandlateraltoeyesAandB. InthespecimenswesawthePAOisdistortedasistherest
ofthebody(Fig.4). Labral formula: 4/554(Fig. 5),with labralpapillaehook-like(Fig. 6).
Abdomen:AbdominaltergiteIV 1.26, 1.8timeslongerthanabdominal tergiteIII.
Chaetotaxy: Largemacrosetaepresentonhead,thoracicsegmentsandabdominal segmentI,with
pointedtips (type two ofChristiansen, 1958). Macrosetae shorterand very robuston abdominal seg-
ment I-VI, with clear barbules. Mesosetae ofdifferent size, with barbs that give them a pubescent
appearance. Bothriotricha 2-3-2 on abdominal segments II-IV respectively, as is characteristic of
almostall Entomobryidae(Szeptycki, 1979).
Tenaculum: With4plus4teeth,andtwosetaeonthecorpus.
Furcula: Denies ringed(Fig. 7)onbasal threequarters,withthefinal portionnarrowedandstriat-
edtransversally. Mucro falcatewithoutbasalspine.
Leg: Trochanteralorganwiththreeorfoursmoothsetae.
Foot complex: Tenent hairtruncate. Pretarsus with a single short blunt seta. Claw elongate, with
thetwoteethofthe internal edgesverybasal, andwithout unpaireddistal tooth inthetwo specimens
weobserved.Unguiculuswithfourlamellaebuttheexternaltwoareverynarrowandfusedabouttwo
thirds ofthe way from the base to the apex oftheunguiculus. Thetwo innerlamellae fused nearthe
apex(Fig. 8).
Type-locality: Brazil, Parnaiba (Piaui), Fazenda Lama Preta, "numerosos ex. sobre a lama e no
"mud-crack" em volta da lagoa", XI.1960. R. Arle leg. Otto Schubart found three specimens from
Pernambuco (Riacho Terra Nova, 5.IX.1937). Material deposited at Museu Nacional, Universidade
Federaldo RiodeJaneiro.
Remarks: The PAO ofTV. schubarti was described byArle as a vestigial vesi-
cle. Barra (1999) described it as a vesicle with a cavity on the top, but probably
this observation resulted from the poor condition ofthe material he saw, long in
ethyl alcohol and collapsed. The SEM examination ofaparatype revealedthat the
PAO is a vesicle larger than described byArle; Figure 4 shows clearly the outline
ofthe vesicle and how it is partially collapsed inward. The chaetotaxy and smooth
seta attheventral side ofthe final whorl ofleg III are similartomost genera ofthe
Entomobryidae. Thetrochanteral organ ispoorlydeveloped, asmentionedbyArle,
withthreeorfourshort and smooth setae.Arle mentioned an almost imperceptible
unpaired ungual tooth but we saw none under the SEM. The "type five" setae
(Christiansen, 1958) are similar to those seen in Entomobtya (Fig. 7). The pecu-
liar hooked labral papillae are similar to those seen in some species of
Orchesellides, Heteromurus and Dicranorchesella (Mari Mutt, 1985). The seg-
mental ratios and the presence of6 segmented antennae indicate that this genus is
best placed in the subfamily Orchesellinae.
Vol. 115.No. 1.January& February2004 33
=
Figs. 1-4. Nothobn'aschubarti. 1, Lateral habitus showingcoloration, lengthofbar 0.1
mm. Figs. 2-4lengthofbars= 10micra.2,Firsttwoantennalsegments, showingthebasal
subdivisions (SEM). The arrows point to the end ofthe two subsegments. 3, First anten-
nalsegment, PAOandfirstommatidia(SEM).Thearrowpointstotheendofthefirstsub-
segment. 4, Detail ofcollapsed PAO (arrow) and two first ommatidia (SEM).
ACKNOWLEDGEMENTS
WearegratefultoDr.MariMutt(DepartmentofBiology,UniversityofPuertoRicoatMayagiiez)
forhisusefulinformation,andtoDra.deMendoca(MuseuNacional,DepartamentodeEntomologia,
UniversidadeFederaldo RiodeJaneiro, Brazil)forthe loanofthetypematerial ofNothobryawith
thepermissiontoprepareaspecimen forSEM. Stephanie Petersonassistedinthepreparationofthe
manuscript.
LITERATURE CITED
Arle, R. 1961. Novas especies de colembolas aquaticas (Notu prdmiinar). Atas da Sociedade de
Biologiado RiodeJaneiro5:34-37.
34 ENTOMOLOGICALNEWS
Figs. 5-8. Nothobryaschubarti(SEM), length ofbars= 5 micra. 5, Labrum (square: Fig.
6).6,Detailofhook-likelabralpapillae(arrow). 7, Partialviewofthecrenulatedens,with
two setae to show their barbule morphology. 8, Unguiculus showing three ofthe four
lamellae andbasal part ofthe unguis.
Barra,J.-A. 1999. UnnouveaugenreCapbiyaavecdeuxnouvellesespecesdelaProvinceduCap
(Rep. Sud Africaine) (Collembola: Entomobryidae). Bulletin de 1'Institut Royal Des Sciences
NaturellesdeBelgique69:19-24.
Bellinger, P. F., K. A. Christiansen, and F. Janssens. 1996-2004. Checklist ofthe Collembola:
Families, http://www.collembola.org/taxa/collembo.htm [Last updated on 2004.03.29 by Frans
Janssens].
Christiansen, K.A. 1958. TheNearcticmembersofthegenus Entomobrya(Collembola). Bulletin
ofthe MuseumofComparativeZoology, Harvard 118:440-545.
Mari Mutt, J. A. 1985. Three new species of Orchesellides from North Korea (Collembola:
Entomobryidae: Orchesellinae). International Journal ofEntomology, 25(4):297-309.
Szeptycki,A. 1979. Chaetotaxyofthe Entomobryidaeandits Phylogenetic Significance, Morpho-
systematic studies on Collembola. IV. Polska Akademia Nauk Istytut Zoologiczny Krakow
1979:45-47.