A hundred-year-old worm?

4 Pages·1994·0.94 MB·English

by  R. J. Blakemore

A hundred-year-old worm?
R. J. Blakemorel and K. L. Elton2
'Department of Zoology, University of Queensland, Brisbane, Queensland 4072
Present Address: CSlRO Entomology, Canberra, ACT 2601
?Department of Agricultural Chemistry and Soil Science, University of Sydney, New South Wales 2006
ABSTRACT
-~~
IS reTd.h .e. . es aA. ubset.d.r a- .iln ia- n~o ce taarl t,h awn.o r ImlL. sS-trorae-tnl oc-ne- r 1si e- lpl-ar o rnv-laa-ce-lde- aa ,vni o (.F ltest clhaex- ro n1o8.m.8-9y,) ,I1sM dw sacsum~s~ls ee~cd~i d~Sa~p~e e: Oc- ~limwecnhsa~w ~ee tca~el .
mlleclec from manage0 and at R~chmonaN. SW, a regon wlUlin ifs onginal dlstnbutlon range. I1 was
In close assoclatmn wlth the lntrod~cedlu mbrlc d Aponeclodea lrapezwdes (D~gbs)T hls s the flrst
cent rmahon of S. macleayr slnce ts deslgnat on over a cenldty ago an0 demonstrates that Ihls natlve
species has survived the clearing, cul~vationa nd introduction of exotic species that has accompanied
Eum~eans ettlement.
INTRODUCTION Type-locality: Sydney (33"53'S, 15lo12'E),
"common in the Hon. W. Macleay's garden at
Earthworms were collected as part of an
Elizabeth Bay" - Fletcher (1889).
agronomic study conducted in 1992123 into
the distribution of soil fauna in pastures near Distribution Records: Mount Victoria, Blue
Richmond, which lies 55 km north-west of Mountains (33"35'S, 15Oo15'E) - Fletcher
Sydney and towards the Blue Mountains,
(1890, variety c(i)); Raymond Terrace (32'47'S,
NSW. There have been few if any systematic 15lo45'E) and Morpeth (32'44'S, 151°38'E)
surveys in this region apart from the early - Fletcher (1890, variety c(ii)); Coona-
reports of Fletcher (188&9O), consequently, harabran (31°16'S, 14g018'E) and Gunnedah
no comprehensive guide to earthworms exists. (30°59'S, 150°15'E) from the banks of the
Moreover, earthworm identification usually Namoi - Fletcher (1890, variety ~(iii))a,l l in
entails the sometimes laborious task of micro- NSW; ?Deniliquin, NSW (35'33'S,144'58'E)
scopic dissection before a specimen can he - Barley and Kleinig (1964).
compared with descriptions of species that are
known. This paper describes the process of Syntypes: W1344-1345 in the Australian
identification of one native species. Museum listed by Reynolds and Cooke (1976).
METHODS AND CONVENTIONS Material examined: Richmond, NSW
(33"36'S, 15O044'E) from the Yarrumundi
Dissections and illustrations were by RJB paddock 3 of the University of Western
using a Wild M5 microscope with camera Sydney, Hawkesbury campus. Collected by
luclda. In the figure (Fig. l), the clitellum is Karen Elton, January 1993, under grazed two
shown shaded. Abbreviations used are: i ii, year-old sown grasslmedic pasture following
etc., segments numbered from the peris-
oats in a paddock much cultivated previously.
tomium; 112 213, etc., intersegmental furrows, Found in association with the lumbricid
i.e., between i and ii, etc.; a, b, etc., individual
Aponeclodea trapezoides. The site forms part of
setae from the most ventral on each side; a Quaternary terrace of the Nepean and
ACT, Australian Capital Territory; NSW, Georges Riven with soil, mapped as Blackendon
New South Wales; Qld, Queensland; sp.p.,
sand, a slightly acidic, nutrient-poor red
spermathecal pores. podzolic with a well-drained sandy profile to
the depth of sampling (0.9 m).
SPECIES DESCRIPTION
Deposition No.: AM W21710: four mature
Spenceriella macleayi (Fletcher, 1889).
specimens, two contracted on preservation,
Comb. nov.
two relaxed hut macerated (one a posterior
(Fig. 1)
amputee). All inspected, one of each dissected
Perichaeta maclea9 Fletcher, 1889: and one contracted specimen drawn (Fig. 1).
155S558.
Perichaeta macleayi var. c (i)-(iii) (?non
P. macleayi vars. a and b) Fletcher, 1890: ~ ~features t ~ ~ ~ ~ l
I. n. n. -~ -0..0 .7 ..
Megoscolex macleayi; Beddard, 1895: 376; Length: 40-75 mm. Width: mean about 4
(?non vars a, b); Michaelsen, 1900: 223. mm. Segments: 90 for all three complete
December 1994 Australian Zoologist, Voi. 29(U) 251
Female pores: paired on xiv, just anterior to
setal arc nearly the width of the mid-ventral
gap. Male pores: largish lateral slitse quatorial
on xviii on summits of a pair of opposed
raised porophores. Genital Markings: in x
and xi, a pair of raised ventral mounds
extending from a to c setae,e ach with a trans-
lucent, ellipsoid rim to an eyeJike pore on the
summit. The anterior pair slightly larger. In
xvii and xix are paired genital papillae, just
ventrad to the line of the male pores, on each
side are a presetal and a postsetal pair; in
addition there are smaller mid-ventral genital
markings, a pair presetally in xvii and a pair
(an analogue in one specimen) postsetallyi n
xix. In xviii a single presetal mid-ventral
papilla was sometimes present. The anterior
annulus of xvii and the posterior annulus of
xix are tumid where they accommodate the
ventral papillae thus the male field appears as
a.basin-shapedd epression.
Internal anatomy
Septa: 415 weak to anterior of gizzard,
516 and 617 displaced and adpressed by
gizzard,t hickening to 9/10 or l0/l I thereafter
thinning to become membranous after L4l15.
Dorsal blood vessel: single, continuous onto
pharynx. Hearts: commissurals viix, hearts
x-xii. Gizzard: large barrel or cone-shaped in
v, has muscular sheen but can be readily
deflected. Calciferous glands: oesophagus
Figure 1. SpencerielLam acleayi (a) ventral view with (b) right- dilated in viii-x and in xiii, but more so in
hand-side prostate gland and (c) spermathecae shown in each of xi and xii to form a pair of ventro-
relative positons; (d) dorsal view of prostomium. laterally sessilec alciferous glands that have
internal lamellae (i.e., two pairs). Supra-
oesophageal vessel not detected. Intestine
specimens.S light secondarya nnulation from origin (caeca, typhlosole): xv, acaecate,
vi. The posterior eight segments dorsally typhlosole not found. Nephridia: mero-
canaliculatei n one sDecimen.C olour: dorsum nephric with pairs of large tufted nephridia
dark-reddish to chbcolate brown especially ventrally in iv-vi, reducing to parietal forests
anteriorly, setal auriolae and ventrum pale, of micromeronephridia by the clitellar region
clitellum buff. Cuticle not especiallyi ridescent. and thereafter. Pre-septal funnels not seen
Prostomium: open epilobous or closed by (possibly numerous per segment?). Sperma-
a fine groove parallel and close to inter- thecae: two pairs in viii and ix with large sub-
segmental furrow l/2. Peristomium ventrally spherical or elongate ampullae tapering to
cleft. First dorsal pore: 5/6 (by mucal ejecta), ducts each bearing near ectal end a shorter,
continuous on clitellum. Setae: perichaetine white, digitiform diverticulum. Ovaries: in xiii
(numerous) from ii: 2Olvii and t24lxx, as a large pair of palmate strands of numerous
with wide mid-ventral and mid-dorsal gaps egg strings with paired diaphanous funnels.
which preclude setaeb etween the male pores. Male organs: holandric, paired sacsi n x and
Nephropores: not seen (enteronephric). xi contain unusually large palmate or "tufted"
Spermathecal pores: in 7lB and 8/9, difficult testes and non-iridescent. nebulous funnels.
to determine in deep intersegmental furrows Paired seminal vesicles are lobulate on
approximately as wide apart as male pores posterior septum of ix and racemose on
(i.e. in line with setae c or d). Clitellum: anterior septum of xii. Prostates: large, multi-
annular over r/zxlli-Vzxvii, interrupted lobed racemose glands extending over 24
ventrally in xvii, furrows and setae retained. segments between xvii and xx, with short
252 AustraliaZno ologistV, ol.2 9(34) December1 994
muscular ducts once bent. Gut contents: and (3) position of the two pairs of sper-
when the fine, yellow soil and occasional mathecal pores. Variety c from three locations
organic "husks" were flushed away, large given in the distribution records above), how-
quartz crystals (up to 0.5 mm diameter) ever, were of similar size and consistently had
remained. These were present the length of the distinctive papillae in x and xi with
the gut and may have been selectively "opposite the interval between the first and
ingested to serve as "crop stones" or, alterna- second setae a pair of fossettes". Consequently,
tively, they may represent involuntary ingestion only variety c is included here in the
of a sandy medium. These worms are probably synonomy of S. macleayi whilst the other
geophagous. varieties are provisionally excluded (cf.
Michaelsen 1900).
The arrangement of paired genital mark-
Taxonomic Remarks
ings on x and xi, characteristic of S. macleayi,
This species is clearly assignable to the is found also in S. fecunda (Fletcher 1887a:
genus Spenceriella, Michaelsen (1907), as it 401-02) from the Blue Mountains, NSW,
falls within the range of the generic definition which nevertheless has four pairs of sper-
as emended by Jamieson (1974) (following the mathecae, calciferous pouches in x-xiv and
discovery by Jamieson, 1972, that neotypic last hearts in xiii. Unravelling the relationship
material of the type-species, Spenceriella of S. macleayi with the S. fecunda "variety" from
notabilir (Spencer 1900), had racemose Burrawang, NSW, briefly described by
prostates, rather than tubular prostates as Fletcher (1890: 1007-008) as having only two
originally described by Spencer). The only pairs of spermathecae, is not attempted here.
notable departure from the generic definition
is that there are two, rather than three or Diagnosis: Spenceriella macleayi, as described
four, pairs of calciferous glands. above, is distinguished from other members
of Spenceriella by the combined characters of
The above description agrees on each point widely paired genital markings, each with a
with the original description of external central pore-like depression ventrally in x and
features of Perichaeta (=Spenceriella) macleayi xi; paired papillae in xvii and xix; tufted
(Fletcher 1889: 1556558), especially with nephridia anteriorly; two pairs of
regard to biometry and the arrangement of spermathecal pores in 718 and 819; calciferous
genital markings. They also agree in having pouches in xi and xii and last hearts in xii.
two pairs of calciferous pouches in xi and xii,
which were later described as "so incompletely
pinched off as to be little more than dilations"
DISCUSSION
(Fletcher 1890: 1004). The internal anatomy
concurs with Fletcher's (1989) statement that J. J. Fletcher was one of the earlier Aust-
in other respects this species was like ralian workers who named about 20 native
Perichaeta (=Spenceriella) australis (Fletcher Perichaeta species, besides S. macleayi, in a
1886: 561-65), notwithstanding his mislocating series of papers (188C90). His "varieties" of
the gizzard in vi rather than v (corrected in S. macleayi are perhaps part of a species com-
Fletcher 1887a: 399) and his mistaking the plex, but, as with S. macleayi proper, none
seminal vesicles for testes (corrected in have subsequently been "re-discovered". A
Fletcher 1887b: 602603). Fletcher (1889) footnote by Barley and Kleinig (1964) makes
differentiated his dozen specimens of a passing reference, without further detail, to
Spenceriella macleayi from Sydney from those their having collected Megascolex macleayi
of S. awtralis from Burrawang, NSW, by their (Fletcher) along watercourses near Deniliquin,
smaller size, the presence of genital markings NSW. The above account, then, probably
and possession of only two pairs of calciferous represents the first confirmation of this
pouches rather than three pairs (in x to xii). species since it was designated over 100
years ago.
Fletcher (1890: 1003407) went on to
describe three "varieties" of S. macleayi which Spenceriella, of which S. macleayi is a
he noted separately from each locality. representative example, will probably become
Varieties a and b (from the Blue Mountains, one of the most numerous native genera by
NSW, and Burrawang, NSW, respectively) revision of the heterogeneous congeries of
differed from the "typical form", not only by Perichaeta and Megascolex (see Jamieson and
having 20-60 more segments, but also in (1) Wampler 1979). It is also likely to receive
the number and character of the genital mark- many new species from further collections.
ings (2) the position of the first dorsal pore Sharing several characteristics with the allied
Australian Zoologist, Vol. 29(34) 253
genus +colex Edmonds and Jamieson 1973 Beddard, F. E., 1895. A mgraph o/the &dn Ollgochela.
Oxford: Clarendon Press.
(see Jamieson 1974), it is partially differentiated
Edmonds, S. J. and Jamieson, B. G. M.. 1973. A new genus
by having segmental rather than intersegmental
and species of earthworm (Megascolecidae:
genital markings (the unpaired female pore Oligochaera) from South Australia. Tranr. R. Soc. S.
and lack of calciferous glands of Gemascolex Au1. 97: 23-27.
are occasionally met in Spenceriella). Fletcher. J. J.. 1886. Notes on Australian earthworms. Part
1. Proc Linn Soc. NSW l(2): 523-76.
The current study demonstrates that S.
macleayi persists despite cultivation and intro- Fletcher, J. J., 1887a. Notes on Australian earthworms. Pan
111. Prac. Linn. Sol. NSW. 2(2): 37742.
duction of exotic species that followed
Fletcher, J. J., 1887h. Notes on Australian earthworms. Part
European settlement. It was found in close 1V. Proc. Linn. Soc NSW. 2(2): 601-20.
association with Apmectodea trapendes suggest- Fletcher, J. J., 1889. Notes on Australian earthworms. Pan
ing that this exotic lumbricid is not displacing V. Pror. tin". Soc. NSW. 3(2): 1521-558.
the native species. Interestingly, this was also Fletcher, J. J., 1890. Nates on Australian earthworms. Part
the case in Fletcher's original accounts (e.g., V1. Proc. tinn Sac. NSW. 4(2): 987-1019.
1886, 1887a) where he recorded the presence Jamieson, B. G. M., 1972. The Australian earthworm genus
Spenceriella and description of two new genera
of both native and exotic groups, with A.
(Megascolecidae: Oligochaeta). Mm. Natl. Mw., Vic. 33:
lrapezoides from almost every locality from 73-68.
which he obtained earthworms. Fletcher Jamieson, B. G. M., 1974. Earthworms (Megascolecidae:
(1886) noted that the Hon. W. Macleay's Oligochaeta) from South Australia. Tronr. R. Soc. S.
Awl. 98(2): 79-1 12.
garden at Elizabeth Bay, whence he procured
Jamieson, 8. G. M. and Wampler, J. E., 1979. Bio-
S. macleayi as well as several exotic species, was
luminescenr Australian Earthworms 11. Taxonomy and
then one of the oldest established gardens in preliminary repon of bioluminescence in the genera
Australia to which plants had been brought Spenc~No, F~lchcrodn'Iu( and Ponrodnlw (Mega-
from many parts of the world. scolecidae: Oligochaeta). Aurt. j. Zwl. 27: 63769.
Michaelsen, W., 1900. Dm TIm&h Vol 10: Oligochelo.
ACKNOWLEDGEMENT FriedlPnder & Sohn: Berlin.
Michaelsen, W., 1907. Oligochaeta in Die Fauna Siidwest-
Dr Pat Hutchings is thanked for refereeing
Ausrraliens. l(2): 117-232. Jena: Gusrav Fischer.
the original manuscript.
Reynolds. J. W. and Cook, D. G., 1976. Nmclalvra
Oligochoerologica: a Calalogue of Names, Dwc"p1ias and
REFERENCES Type Specim~lr of the Oligmhekz. University of New
Brunswick: Frederiction. Pp. 217.
Barley, K. P. and Kleinig, C. R., 1964. The occupation of
newly inigated lands by earthworms. Awl. j. Sci. 26: Spencer, W. B., 1900. Further de-ptions of Australian
29&91. earthworms. PTM.R . SOC.V iCI. 13(l): 29-67.
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