Australia's most diverse crayfish habitat?

3 Pages·1997·0.91 MB·English

by  J Morey

Memoirs ofthe Museum ofVictoria 56(2):667-669 (1997)
AUSTRALIA'S MOST DIVERSE CRAYFISH HABITAT?
J. MOREY AND G. HOLLIS
Department ofConservation and Natural Resources, 71 Hotham St. Traralgon, Vic. 3844, Australia
Abstract
Morey. J. and Hollis, G.. 1997. Australia's most diverse crayfish habitat? Memoirs ofthe
Museum ofVictoria 56(2): 667-669.
LabertoucheCreek, atributary oftheTarago Riverin West Gippsland, arguably hasthe
most diverse freshwater crayfish assemblage in Australia. Six crayfish species are known
from the creek, including the rare and vulnerable Warragul Burrowing Crayfish, Engaeus
stemalis. theonly known location ofthis speciesin Australia(Horwitz, 1990, 1992). Other
species ofburrowing crayfish found are E. hemieirratulus, E. eunieularius, and E. quadri-
manus. Two species ofEuastaeus (Spiny Freshwater Crayfish) are also known from these
waters,EuastaeusyarraensisandE. kershawi(GippslandSpinyCrayfish).Athirdspecies,E.
woiwuru. is possibly present, as the creek is shown to be within this species* range.
Introduction stemalis(Horwitz,perscomm). Thepitfalltraps
m
were distributed at approximately 0.5 inter-
Labertouche Creek, a tributary of the Tarago vals at a number of different locations at the
River in West Gippsland, possibly has Aus- study site to determine whetherEstemalis util-
tralia's most diverse freshwater crayfish assem- ises different areas along the creek. This
blage, with six species of freshwater crayfish included pitfall traps located along the bank of
(four species ofburrowing crayfish ofthe genus the creek (<1 m to edge), perpendicular to the
Engaeus (Decapoda: Parastacidae) and two creek (approx 10 m) and in the banks of the
spiny crayfish of the genus Euastaeus (Deca- creek. Several traps installed in the banksofthe
poda: Parastacidae) known to be present and a creek were lost during floods. Trapping com-
seventh species (E. woiwuru) suspected ofbeing menced on 26 Jun 1995 and continues to the
present, asthecreek iswithin itsrange(Morgan, present. A 200 mm high driftfence was erected
s1m9a8l6l),. tAodtualltlebnugrtrhowriarneglycreaxycfiesehdianrge 1g0en0ermalml,y brieetrwdeiernecptiitnfgalglretartaeprsntoumabcterass iantsouptehrefipciitasltbhaarn-
whereas the adult spminmy crayfish are consider- wouldotherwiseoccur.Thisdriftfencehowever,
ablAysluarrgveerytwhaasnc1o0n0ductedintotoctaolnfliernmgtht.he pres- owfascartetmleovaetdtohne 3s1tuJduly 1s9it9e5. dPuietfatlolthterapprsesweenrcee
ence of the Warragul Burrowing Crayfish, checked mostly at 2-5 day intervals.
Engaeus stemalis (Clark), and determine the
suitability of pitfall trapping as a survey tech- Results ofpittfall trapping to mid-November
niqueforthespecies. E. stemalishasbeenclassi- are summarised in Table I. No crayfish were
fied as Endangered by the Department ofCon- caught in traps between 26 June and 8 August.
servation and Natural Resourceson the basis of All species were collected from September
its single confirmed location and as a "taxa in onwards, usually after rainfall, however E.
dangerofextinction in Victoria and whose sur- stemaliswasonlycaptured afterrainfall. E. ster-
vival is unlikely if the factors causing their nalis and E. eunieulariums have so far only been
declinecontinue'operating'(CNR, 1993, IUCN, collected within 0.5 to the creek bank,
a1n98d3)F.auTnhaeGsupaercaiensteweasAcltis1t9ed88unindeMrarthcehF1l9o9r3a wweherreeraescoEr.deqduaadlroingmatmhtesbaannkdaEn.dhuepmiteoir8rmatupleurs-
(SAC, 1993). pendicular to the bank within the cleared graz-
Specimens were collected in pit fall traps ing area. The number of adults collected was
adjacenttothecreekfollowingheavyspringrain almost the same as the number ofjuveniles (14
duringthissurvey. Threepitfall lines, consisting adults, 15juveniles), indicating both age classes
ofbetween 6 and 41 traps, constructed from 90 responded equally to, or took advantage of, the
mm PVC tubingcut into 200 mm lengths, (with wet weather to disperse on the surface. It is still
tiinnglliadsndinatdhjeacbeontttotmo),LawbeerretoesutcahbeliCsrheeedk,in5g0razm- ansotnoknneowonfihtsotwunEn.elstseymsatliesmsresaocfhaersitnhveesstuirgfaatcee,d
downstream from the 1982 collection site ofE. has come to the surface (Horwitz, 1990a).
667
668 .1. MOREY AND G. HOLLIS
Table 1. Engaeus species collected in pitfall traps adjacent to Labertouche Creek 26 Jul to 20
Nov 1995. F = Female, M = Male, u = Sex unknown, ad = adult, juv = juvenile, E
=
quad/tunic unable to identify.
Date E sternalis E hemicirratulus E quadrimanus E cunicularius E quad/cunic
8 Aug lu(ad) lu (ad)
13 Sep IF (ad) 2u (juv)
21 Sep lu Guv)
24 Sep 1M (ad)
8 Oct lu (juv)
14 Oct 2u (ad) 1M, IF (ad) 5u (juv)
21 Oct IF (ad) lu (juv) IF (ad)
23 Oct IF (ad) 1M (ad)
29 Oct lu (ad)
10 Nov lu (Juv) 1M (ad) lu(juv?) 3u (juv)
Total 3 7 6 5 8
Species encountered
Engaeus sternalis. Despite extensive searching,
the only known location in Australia of this
speciesisonLabertoucheCreekandpriortothis Richardson, 1986; Horwitz, 1990b). E. cunicu-
survey, wasfound in complexburrowsystemsin larius is found from near the Otways in western
clayey soils in the creek bank (Horwitz, 1990a, Victoria throughout south eastern Victoria, the
1990b). Nothing is known about its biology or Bass Strait islands and Tasmania (Horwitz,
ecology This species is easily identified by its 1990b).
paleyellow-greycolour,acoveringoffinedowny Engaeus quadrimanus Clark, another com-
hairson its carapaceand dimorphic chelae, and mon species, is very similar to E. cunicularius
very small eyes. but the dactyl is smooth. These two can only be
bisyEainctgsoabmerimugsohtnheobmruiarcnirgroerwaictnluaglwusssp,eScmmiaeinstyheassatinilfdyfihSdaceihnrutssitfaeinred,d dliseinscgtotinhnsgi(utdiiesprhoeefddcaflarlwoosmwtleoaantcidhpsooptfehtceaiirel)sasiasan5ddu0l-ft6os0;unmidfmti.ontaIalt
hvearvye sahorftanantsehnanpaeed. Tchheiimrnebyu,rrwoiwtsh tytpuincnaelllsy nreaangreroafinvfeogreestta,tioanndtypiens fsrwoammpfsernayngdullcireesektso
descending obliquely to chambers which are (Horwitz, 1990b). E. quadrimanus constructs
occasionally just below the ground surface. burrows, usually with more than one opening
Malesand femalesarefrequentlyfoundtogether andoftenwithconical, pelletedchimneys, down
inthesameburrowand areusuallyaccompanied tothewatertable(Horwitz, 990b, Horwitzand
Twcbahhyliijlscyuhveiwsnnpaielsyceieoserl(islgHoiownri-aswolirltyacznc,ogoemv1m9e9cro0lenabdy).indaBdonuemdrnirsnoewawiwtsdeeaetdrsfeposrtroyeeisplatisd.,- NMRieeclwhbaoSruodrusntoenh,Wt1ao9l8eM6as)l.lbDaoicrsodtoertriab,(uHt1oniroewnairitsztf,hreo1m9V9in0cobtr)ot.rhiao-f
throughout its range in Gippsland, usually Euastacus yarraensis (McCoy) is generally
above an altitude of 100m. dark olive green with white and orange claws.
Engaeuscunicularius(Erichson) is acommon Thespineson theabdomen and somebumpson
dspaecctiyels,(tgheenesrmaallllyebrrmoowvnaabnldewpiatrhtthoefttohpescildaew)o,f tFheemaclaersapamcaetuarreeoartancgleosweittho w4h0itmemtipsO/ccceinptirteasl.
slightly rough or granulated (Horwitz, 1990b). Carapace Length, (the distance from the rear of
Often found in sympatry with E quadrimanus, theeyesockettothecentreoftheposteriorofthe
caonndstirnuscitmsilbaurrrhaobwistactontnypeecste(dHotrowithtez,wa1t9e9r0bt)a.blIet cinarsaupracvee)y.s BienrSrieepdtefmebmearletshrhoauvgehbteoenNocvolelmecbteerd
and/or to permanent water (Horwitz and (Morgan, 1986). E. yarraensisis found from the
Tarago River through to the Otways in south
western Victoria.
AUSTRALIA'S MOST DIVERSE CRAYFISH HABITAT? 669
Euastacuskershawi(Smith)(Gippsland Spiny found in adjacent damp areas with more exten-
Crayfish) is usually dark olive green, often with sive surveys. A community awareness program
orange markings on the under-side, but with no and site protection works are currently being
white on the claws, and has sharp spines on the undertaken to protect the habitat of Engaeus
front legs and abdomen. It can grow large, sternalis.
mm
although specimens over 120 carapace
length are uncommon. Females are generally
sexually mature at OCL greater than 85 mm, Acknowledgments
amlatthuorueghbseotmweeesnpec5i0memnsmappteoar8t0o bmemsexuOaCllLy WPheirtmiinsgs,ionto fsrurovmeythoen lhaisndhporlodpeerr,tyMirs grBeaartrlyy
(Morgan, 1986). Recent surveys by the first appreciated. The project was funded by a grant
authorindicatethisspeciesisveryslowmgmrowing, from the Australian Heritage Commission.
averaginganannual increaseofonly 7 OCL.
Specimens have occasionally been found many
metres away from permanent water. Some indi- References
viduals construct burrows oftype \b or 2 (Hor- CNR, 1993. ThreatenedFauna in Victoria. Depart-
witz and Richardson, 1986), adjacent to river ment of Conservation and Natural Resources:
banksFound from the Tarago River to almost Melbourne.
the New South Wales border in southerly flow- Horwitz, P., 1990a. The conservation status ofAus-
ing rivers and streams. tralian freshwaterCrustacea.Australian National
A third species of this genus, Euastacus Parks and Wildlife Service Report Series No 14.
woiwuruMorgan ispossibly present,asthecreek Horwitz,P., 1990b.Ataxonomicrevisionofspeciesin
iswithin the species' range, (Morgan, 1986) but (thDeecfarpeosdhaw:aterPacrraasytfaicsihdagee)n.usIEnnvegrateeubsratEericThasoxn-
aipssoosyrielmtyilhsaarpsiinnnoetdsib(zeeMeotnrogrEaency,oavre1r9ra8ee6dn)s.dius,ribnugtsurrelvaetyisv.elIyt Horwiolotngzoi,cmaPyl.cH4l:.aJs4.s2ia7fni-cd6a1tR4iio.cnhoafrdtshoenb,uAr.roM.w,so19f8A6u.sAtrnaleicaon-
Priortothissurvey,Esternaliswasonlyfound freshwatercrayfish.AustralianJournalofMarine
by destructive samplingofthecreek bank, how- and. FreshwaterResearch 37: 237-242.
ever results show that pitfall trapping is a feas- IUCN, 1983. The1UCNInvertebrateRedData Book.
iblealternativeofsurveyforthiscrypticspecies, International Union for Conservation ofNature
as well as for some other species of burrowing and Natural Resources, Switzerland.
crayfish. It appears that E. sternalis, along with MorgEauna,stGa.Jc.u,s1C9l8a6r.kFr(ePsahrwaasttaecridcraaey)fifshroomftVhiectgoerniuas.
other sympatric species, respond to rainfall and Memoirs ofthe Museum ofVictoria 47: 1-57.
increasinggroundtemperatureforaboveground SAC (Scientific Advisory Committee, Flora and
dispersal. Fauna Guarantee), 1993. Final recommendation
Preliminary results confirm Horwitz's on a nomination for listing: Engaeus sternalis.
opinion that E. sternalis isconfined tothe creek Department of Conservation and Natural
bank, although no doubt the species could be Resources, Victoria.