In various areas along the coast in the vicinity of Monterey there are many colonies of the Polychaete worm Dodecaceria pacifica.  An attempt has been made to find out something of the distribution, size, structure and the flora and fauna associated with these colonies

Boone, Winston B.

Aquatic Commons

'Jins ton Boone
lool. 32J.2
!f].IinorU Problem lieport
Summer 1950
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1~ P.:tELL~I.H~l\Y STUDY ON DO::D:::;;(t\CJ.:RIA p ~CIFICA (}':'JKES)
In various areas along the coast in the vicinity of
Monterey there are many colonies of the Polychaete
wor~ Dodeaaoeria Raaitiea.An attempt has been made to
finQ out something of the distribution. size, structure
and the flora and f~dassoeiated with these colonies.
Introduction
Dodecaoeria paoi1'io"a (Fewkes) is a Polychaete worm
belonging to the iamily CirratuJ.idae. The worm range in
size from 12 mIn to 38 rom averaging around 23 mal. There
are 60 to 100 well marked segmenta~s of the body.
Immediately behind the rather narrow prostomium is a
pair of grooved papillae. .:)1 tua ted "behind the papillae
are 4 to 5 pairs of tentacular cirri e~ch ?air slightly
dorS21 to tha preceedin~ pair. ~here are no eJ8s.
~he aolor in lile is a ~ ark greenish or brownish
11aek ..
The worms 1'ona a colony of aalo£,reous tubes, greyish
white, in dense masses fOl-ming a m~trix riddled by to~tuous
galleries.
The worms wld colonies studied were found at
Pescadero Point, ~.silim~rt :Coint rinos, Ghina }loint,
:.ionterey Boat wOi."ks beecll &nc.. t:i1e ::on tel'ey Boa"1i Har0 or.
~olonies were colleatau, worms, tti0es end colonies
:aeaS1li';;;G. c.-:au dissJcted..
Distribution
Colonies are found intwo'different localities.
The firs t of w:li eh I aall the Open COBS t areas used by
ilioketts and Calvin to designate places such as Point Pinos,
Pesoadero Point. eta.
In this type of locality the colonies are fewer,
smaller ~nd less prominent than ones found in the
second type. the Protected Open Coast area.
Colonies ~ere tend to be on the back sides of rooks
faoing away from the open sea or in cl'evices in tide
pools.
The r~nge of ocaur~ance is frow about the middle of
zone 2 to a few colonies in zone 4. )Plate I Fig. I.}
The most aJund~nt numJers bein in zone 3. The Ricketts
and Galvin zona tiOll is ~1ere used.
Colonies dq not se0m to occur in the flat tide pools
which arc o:boliked v,i th sea-weed.
The ~onteray Boat H&rbor anG the !~nteray Boat
~'rorks bes.ell near China }oint are examples of th-:} Protected
Open Coast. It is in these &reas \1Uere numerous prominent
colonies are found.
The ren~:.a of Qccurance is from about lower zone 1
to lower zone 4. (Plate I Fig. 2) Coloni~s in lower
zone 2 and. upper zone 3 see~l to att&in the greatest
size. In the lovler ~ones the colony mass often covers
Co.
or encircles t ~ock c08pletely. In the hi~her zones the
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COll)~li;s tnd. "'.;0 f&ce the OC6fi.n bl1<l "Je loc<:. tet on one
side of the rock only.
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offers the correct oondit~ons of exposure to w~ve shook
',/hioh ~110'{1 ::or Btro~. devulcpment of the colonies •
.Apparently the wave shock preve1l:m t on ti13 Optln COl:~st
restriots the grQwth of laree outstanding oolonies.
jolo~ies were muc~ more ntunerous per unit of area
in the Protected Open Co~st localities than out on ~le
Open Joast. In tee l.:onterey Boat Works area approximately
160 oolonies over 21.- i'eet squa.re Viere counted along a
300 yard front of' the intertidal. Lo cl;~tion of colonies
in the Open Coast was vel-y spotty ranging from 15 to 20
colonies per 300 y~rds along the intertidel. {Plate I Fig.~)
Form an': Size
There are generally two types of colony formation.
The first is e relatively thin encrustinb type typically
found in the oore expose~ areas such ~s the Open Coast.
The colony is found oore olten in crevioes ,8nd cracks
and on the shore side of rocks.
These colonies are smaller than ones in the ~ore
protected areas, rane;ing from about 6 lt X 6Tt X l~n to
2it' X ?i' X 3".
The seoond type is larger, rounded and very prominent.
0010n1es often are rather kidney shaped oirclins or covering
the rocks.
Some colonies may oecome very lm~ge. One near the
old marine tr&ck in the ~onter~y Boat ~orks ar~a
in this area measuring
weed Ulvawas invariably found in these spots. From
p.
deep.
casa c.:ppe~re to alw&ys use rook as a substrate. One
3tru..oture
observation it seems reasonable to assume that wherever
About 5 out of every 12 colonies had dead spots of
:,j.;
Q1ter 56..R ·X 30ft X 20n •
ille colonies measured in the Boat Harbor averaged
l' . ~.
s&mewhat sm~.ller about 20" X 151t X 10" t although one
.1aad ooloDy 1E.lS 60" X 3811 X 161t •
One rock had a group of 7 colonies massed upon it
from 3" to !" in diameter on their surfaces. The sea
small colony was founa attached. to the concrete piling
• fl:I.$ tubea oonetructed. by Dodeoaoeria are for the
~~$t part .alcareous as indicateu by treating samples
from all areas with hydrochl~ric and aoetic aoid.
The Qolony 1s a. ttached. to ro ok and. except tor one
,
'which described an 18 foot arch 4 feet wide and 4 feet
the Ulvs. 5tate a foothold sand and mud accumulates in the
holdfast and kills the worms inhabiting the tubes
.~d~~neath. Th~se <lead spots were observed. to be mostly
onthe"shor.e e1ds of the rocks where the wave shock tends
...eOm:plata~1 l,tcvers a lare;e rock &nd measures 88it' X 57"
:;- •• -:: .. _ 0'" •
:t."," look1.ng like this from a Jove:
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"l 1
of the Konterey Munioiple Wharf about in Zone 3.
The oolony seems to be oonstructed in tiers or
gallerias. of tubes: The galleries below the outermost
are about 5 to 8 centimeters deep and appear to be closed ..
off from higher and lower galleries. _then examined
most tubes 'Viere found n': t to travel from the, 'perimeter
to the center. The lower galleries were also always dry
and olean. The worm resides in the outermost gallery.
The tubes are very winding and tortuous. Length ave-
raged 15 mm in depth and l~ to 3i mm Wide.
Various outs were made into many different andonies
and measurements were taken. In 2t weeks no disoernable
evidence of rebuilding or repair has been noted.
It was found that the worms oooupy a "U~Sihap,dtt
position in ~he tube. Head and posterior postion both
sticking out af the tube when under water. Commonly
head and tail of a worm utAlized the same'ape~ure
but in many cases the posterior portion of the animal has
its own opening to the outside. This position in the
~be no doubt is necessitated by the faot that
Dodeaaoeria has no means of ;olearing the tube of fecal
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material $f it were to be deposited in the tube.
A varying number of worms were found inhabiting the
same tube. The range was from 1 to 4 the average number
being 2 per tube. (Plate I Fig. 4) In Some cases all
of the worms had separate openings for the tails, in other
cases every worm was doubled back on itself and ,the
posterior part was in the same opening as the head.
The~e were also some cases where both oonditions existed.
About 3 out of 10 tubes oontained one individual,
t~e middle of the body often sharing a oommon chamber
with nearby worms.
- ~~~.::. rA'(.. H~'rUftc
""""1A- *;:.....~__~-~~EO,i , ~o;r"'f
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2-- Woit '"'f~ :si:pll!=~,;rr~ rlI-r-
S ... 'C tc~£, e 0 ~;I¥D~ C!.~,e.,"'I!1'A
6e~ocu
In measuring 10 sets of 3 warms inhabiting the same
tu'be it was found that the varia tion in size of the worms
in one tube was relatively small. The average difference
1n length being 3.4 Mm. These samples were taken from
different oolonies ooming both from the Open Coast and the
Proteoted Open Coast.
Lengths of Worms in !!I~illimeter s in Same Tube
Worm II 1. 14.0 ,1. 16.5 1. 23.0 1. 18.5 1. 34.5
2. 13.5 2. 17.0 2. 19~5 2. 18.5 2. 29.5
3. 15.0 3. 15.0 3. 21.0 3. 19.0 3. 31.0
Range of
Differenoe 1.5 2.0 3.5 0.5 5.0
Worm :# 1. 22.0 1. 27.5 1. 27.5 1. 19.5 1. 22.6
2. 11.5 2. 26.0 2. 25.5 2. 20.0 2. 26.0
3. 22.5 3. 27.0 3. 24.0 3. 24.5 Z. 29.0
Range of
Differenoe- 5,0 1.5 3.5 5.0 6.5
Average of differenoes 3.4 mm.
These facts seem to indicate that perhaps the in-
habitants of these 'tubes are not parents and offspring.
This of oourse doesn't answer the perplexing question
of how new individuals are added to the oolony but
might indicate at this time of year new individuals
aren't being budded off.
(",t.;)
Hartman states that Dodeoaoeria pacifica is
ep1toKous as is the ~opean species D. concha~.
No signs indiaating worms in an epitoXous state were
found. However it would be necessary to observe worms
the year round to obtain more information on this ~bject.
. (!'''IJlf'tz). (1'1)')
Neither the Berkeleys~nor Moore~give any informat~on
on this subject. restricting themselves to a desoription
of the species ..
It aeameto me that with more time and more extensive
methods this subject of reproduction in DodecQcerla
would be very illuminating and profitable.
The ~anner of feeding also needs further and more
intensive inv8stieation. Worms obtained from the Boat
eHarbor were seen to def1cate strings of oleaned sand
~.
bound with muous. The eastings of worms trom .the
Open Coast were green and seemed to contain organio
material. However it should be stated that I was never
able to see any of the worms actually ingest either
sand or plant and animal material.
Associated Plants and Animals
Many animals ~nd a tew plants were found living on
the oolonies. Only two animals the Spionld worm
Boocardia natrix and the Polynold Phylloohaetopteris
prolifica both Polyohaete Annelids were found in the
Dodecaoerla tubes or in tubes of their own between the
tubes of the colony.
Plants
*m:.Y.! laotuoa
Endoollda sp.
Coralline Algae
• ...... .., 1'"-
~Abu.ridant
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Animals
Coelenterate.
Aglaophenil:\. sp.
~unodaQt1s .elei!AtisSlma
~M.tridlum.d1anthu8
~Anthop~.ur$ sp.
Nemst 0'\1. .', ,
Various unidentified speeiman.
cNemert1nia
Amph1porus 1mpariapinoijA
Gephyrea '
c! ....
* Pl!Japs!.'om. age;azz1
Uroohordata
"i.tAmaro.alum. californ1QUJI.
HaoroelUlum pelluo1dum
Mollusca
!lo;ea11a ciliata
I..i ttor1na planq1§
6-AC!!apEill;\a
.!hai' emarg1nat8
!ltl1u. callforn1anUi
IC$111a .p.
Arth,ropoda
Inliect larvtlf
Mlte$, 2 tlpes unidentif18d
Crustaeea
O.tracot.
Copepode
Arapltho1dae sp.
oolonies at different plaoes along the coast.
3. There are at least 2 different types of oolony
formation.
4. The structure of the oolony is very oomplex.
5. ~orethan one worm may inhabit a single tube.
6. 'I'here are many plant and animal associates.
It is evident that there are many' questions which
need study such as, the reproduotion of theBe animals,
feeding mechinisms, how new members are added to the
COl041y, whether or not the worms inhabi tion the 2
colony forms are of the same speoies.
Further investigation would doubtlessly be very
profitable.
EIBLIOGRAPHY
~e~~elel, E. "Polycheatous Annelids from the Nanaimo
1929 - District n • Part 4. Chaetopteridae to
Maldanidae.~ Studies from the Eio. Stations
of Canada. Vol. IV No. 22 Univ. of
Toronto Press
~erkeley, E. and C. "On a Colleotion of Polzohaetes from
1941 . - Southern California." Bull. of Southern
Calif. Academy of Soi~noes Vol. XL Part 1
B~rkelel, E. and C. "North Pacifio Polyohaetes. Chi,fly
1942 . From the West Coas~ of Vancouver Island,
Alaska and the Bering Sea." Canadian JoUr.
of Researoh Vol. 20
Hartman, Olga. 'The polyohaete Annilids of the Littoral
1936 Zone of the PaoifiQ Coast". Ph. D. Theisis
L1tht, !. F. "Laboratory ~nd Field M~ual in Invertebrate
141 Zoology". Assoa. Students store Univ. of Calif.
M'Intosh. "Notes from the Gutty Marine Laboratory
1'11 st. Andrews. On the British Cirratulidaen •
No.XXXII Annals and Magazine of Natural
History . Series 8 Vol. 7
Moore, L. P. nPolyohaetous Annelids from Monterey Bty
190§ - and San Diego California". ~rooeedings of
the Academy of Natural Scienoe of Calif.
PLATE I
Distribution
Open Coast
Zone 1
:~; 2
3
4
Oc:cult~ AJc.e
(:f1g. 1)
Open Coast
Proteoted Open Coast
Zone 1
oC!.Ct. UL It If.A/l!.. e
(fig. 2)
Protected
Open Coast
(:fig. 3)
Number or tubes
25 50 100 125
Number of colonies averaging over2+ feet square.
15~
10
o'--... ..... _
l
1 2 3 4(fig. 4) Number of worms inhabiting same tube
out of 37 tubes disseoted.


A preliminary study on Dodecaceria pacifica (Fewkes)

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A preliminary study on Dodecaceria pacifica (Fewkes)

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