Feeding and behavior of polychaetes
P. Mark, E. Whitaker
VTRODUCTION
The polychaete families Arabellidae and Lumbrineridae are very
similar externally. Both lack prostomial appendages and have verm-
iform body shapes. The two families are assigned to the super-family
Eunicida on the basis of similarities in jaw anatomy and nephridia
(Hartman, 1944; Dales, 1962). Both Hartman (1944) and Dales (1962)
have hypothesized that some of the superficial similarities of these
families could be due to evolutionary convergence. However, Day
(1967) further emphasizes their basic relationship by making them
sub-families of the family Eunicidae. He makes this assignment based
on jaw characters and the presence and number of prostomial appendages,
branchiae and dorsal cirri.
Similarities between the groups at the family level are obvious,
but there are also differences, especially in setal types, in jaw
structure, and in the presence or absence of eyes. Arabellids often
have eyes, and they have limbate setae throughout. They are reported
as essentially burrowing, predaceous and carnivorous, but some species
have been found to be endoparasitic in other worms during their juve-
nile stages (Pettibone, 1963; Day, 1967). Lumbrinerids have hooded
hooks in posterior body segments and usually lack eyes. They are
considered to be chiefly carnivorous and burrowing (Pettibone, 1963;
Day, 1967).
According to Hartman (1968) there are 12 species of Arabellidae
(four in the genus Arabella) and 20 species of Lumbrineridae (eighteen
in the genus Lumbrineris) in Californian waters. The species Arabella
iricolor, A. semimaculata, Lumbrineris zonata and L. erecta (Figures
and 2) proved to be readily available in Monterey Bay, California,
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
and they form the subjects of the present study.
Arabella iricolor (Montagu, 1904) is cosmopolitan, occurring in
rocky habitats and sediments. It is thought to be a predator (Hartman,
1944; Pettibone, 1963; Day, 1967). Pettibone (1957) states that juve-
niles have been found parasitic in the body cavity of Diopatra ornata.
A. semimaculata (Moore, 1911) occurs from W. Mexico north to W.
Canada and is also thought to be predatory. (Figure 1.)
Lumbrineris zonata (Johnson, 1900) and L. erecta (Moore, 1904)
are burrowers in sandy sediments (Hartman, 1944). Members of the
genus Lumbrineris are considered to be carnivorous, although it is
not known whether they are predators or scavengers (Pettibone, 1963;
Day, 1967). (Figure 2.)
Hartman (1944, 1968), Dales (1962), Pettibone (1963), Day (1967),
Richards (1967) and Fauchald (1970) have looked at taxonomy, distri¬
bution and selected aspects of behavior in representatives of the two
families. Yet beyond casual observation and conjecture, very little
is known of the similarities or differences in the Arabellidae and
Lumbrineridae beyond anatomical details. We studied distribution,
feeding and selected behavior of A. iricolor, A. semimaculata, L.
zonata and L. erecta in the interest of making comparisons in some
aspects of their natural histories. All studies were carried out
at Hopkins Marine Station of Stanford University, Pacific Grove,
California, in April and May, 1976.
DISTRIBUTION OF SPECIE
The first step in the comparison was to investigate a variety
of habitats and note the occurrence and distribution of each species.
0
1s
Laser
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Figure 7. Arabella a. A. iricolor, dorsal view of anterior portion.
b, frontalr view of parapodia from mid body region.
c. A. semimaculata, dorsal view of anterior portion.
d. frontal view of parapodia from posterior body region
showing characteristic up-turned post-setal.
Figure 2. Lumbrineris. a. L. zonata, dorsal view of anterior end.
b. afrontal view of parapodia. c. L. erecta, dorsal view
of anterior end. d. frontal view of parapodia from pos-
terior body region with up-turned post-setal lobes.
Feeding and behavior of polychaetes

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b.

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25mm
FIGURE 1
A


25mm
FIGURE 2
P. Mark, E. Whitaker

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2




1 2mm
5






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etletlagtl
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Collections were carried out in three different habitats: the
rocky shores near Hopkins Marine Station at Mussel Point, Pacific
Grove; the marina at Monterey Harbor; and commercial wharf 2 at
Monterey, California. Phyllospadix roots were collected by hand
from the sandy channel on the east shore of Mussel Point at low tide.
Phyllochaetopterus tubes and clusters of tunicates were gathered from
wharf pilings and from floats at the marina by hand or using skin or
SCUBA diving. Worms were separated from the substratum in the field.
They were stored in the laboratory in running sea water at 12-13° c.
Results of the study are summarized in Table 1.
Arabellids were found almost exclusively at the wharf and marina,
subtidally. A few A. iricolor but no A. semimaculata were found in
Phyllospadix roots. Arabellids in Phyllochaetopterus tubes and tuni-
cate clusters usually were situated at the site of attachment.
Lumbrinerids were found only intertidally in Phyllospadix roots.
No lumbrinerids were found at the marina or wharf. L. zonata popula-
tions vary greatly from place to place within the low intertidal zone
(O to -2 ft.). The worms were found only in sand or coarse shell frag¬
ments in and under Phyllospadix roots, not in plain sand in beaches or
in any algal holdfasts.
It has been reported by Donat (1975) that both lumbrinerids and
arabellids occur in Phyllochaetopterus tube communities at the wharf.
Our collections were not substantial enough to comment about this
finding.
Although populations of other organisms present at the collecting
sites were not counted, it is our impression that under Phyllospadix
roots where the available space may be limiting, the number of
P. Mark, E. Whitaker
Feeding and behavior of polychaetes
Table 1. Distribution and abundance of arabellid and lumbrinerid
species in selected habitats in Monterey Bay,CCalifornia.
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 1. Distribution and abundance of lumbrinerid and arabellid
species in selected habitats.
No of worms per 100 cm of substratum
Habitat
Arabella
Lumbrineris
Lumbrineris
Arabells
iricolor
semimaculata
erecta
zonata
n-46
n=111
n=22
n=6
1. Underside of
styrofoam floats.
Monterey Harbor
marina
Phyllochaetopterus
tubes, clusters of
Ascidia ceratodes
Concrete pilings
of Wharf #2,
Monterey Harbor
1.3
Phyllochaetopterus
tubes
3. Mussel Point,
——
O ft. 5.5
Pacific Grove, CA
-2 ft. 12
Phyllospadix roots
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
lumbrinerids present varied inversely with the number of Cirriformia
spirabrancha.
The rare occurrence of A. iricolor, A. semimaculata and L. erecta
intertidally suggests that the bulk of the populations are subtidal.
At the wharf Donat (1975) found A. iricolor and L. erecta subtidally
to -1.5 meters. He did not find any A. semimaculata.
FOOD HABIT
The second part of this study involved investigating the dietary
differences between the four species by analzing fecal pellet contents.
To do this, freshly collected specimens were brought to the lab,
cleaned, and separated by species and collection sites. Groups were
placed in finger bowls of fresh sea at 12-14°0. and, after varying
time intervals, fecal pellets were collected from each bowl and mounted
in glycerine. Examination under a compound microscope (and consulta¬
tion with faculty members) permitted identification of the contents.
Approximations to within 10% were made for the percentage content of
each constituent in each fecal pellet. These results were then used
to calculate the mean percent content of each constituent for each
species. Complete results are found in Figures 3 and 4 and Tables 2
and 3.
Both species of Arabella show lipid, well digested animal material,
and sulphur bacteria in their feces. The percentage of sulphur bacteria
was significantly different between the species in the marina collec-
tion, though sample size was small. However, the sulphur bacterial
content for A. iricolor from both habitats was not significantly dif-
ferent. Percentage detritus was at a consistent minimum with small
variance. Both species had no animal hard parts in their feces.
C
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Figure 3. Arabella. Fecal pellet content of A. iricolor and A. semi-
maculata. Mean percentage composition of each component
for worms from Phyllospadix roots (Hopkins) and the Monterey
marina.
10
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
FECAL PELLET COMPOSITION
A. Iricolor, A. semimaculata
100
ZL
7
H

O
O
0
6
L
d
Mean %
a
Composition

C

C
d

o

O
species
A. iricolor
A. semimaculata
A. Iricolor
A. iricolor
collection
Mari na
Marina
Hopkins
„ Jotal
Site
KEY
unidentified
organit detritus
animal matter
sand
Wpid
sultur hacteria
□other
FIGURE 3
0
P. Mark, E. Whitaker
12 Feeding and behavior of polychaetes
Figure 4. Lumbrineris zonata. Fecal pellet content. Mean percentage
composition of each component for groups of worms collected
from Phyllospadix roots at Mussel Point from the same tidal
zone atitheesame time.
12
Feeding and behavior of polychaetes
P Mark, E. Whitaker
FECAL
PELLET COMPOSITION
L. zonata
100 -


2 2
5 5
a

O

aa
Mean %
Composition
O
W


9
Collection
A
Tidal
Level (ft.)
Endocladia
KEY
blue green algae
other red algae

other -plant
Phyllospadix
FIGURE

O

E
84
55
other - animal
detritus
sand
0
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 2. A. iricolor and A. semimaculata. Fecal pellet contents by
mean percentage from the Monterey marina and Hopkins Marine
Station (Mussel Point) on Monterey Bay, California. To
supplement Figure 3. Standard deviations and ranges are
also included.
Feeding and behavior of polychaetes
Table 2.
Location
Monterey
Mussel
Content
Point
marina
A. iricolo
A. iricolor
n=11
n=12
Digested
.41.46
.684.46
animal
material
(.10-.80)
(.10-1.0)
.371.36
.414.36
Lipid
(0-.40
(0-.60)
040
Sulphur
.14.10
bacteria
(0-.30)
((0)
.151.03
.154.08
Detritus
(0-.10)
(0-.30)
.03
Sand
(0-.20)
.01
.0
Other-
(0-.10)
(0-.20)
P. Mark, E. Whitaker
Monterey
marina
A. semimac.
n=11
.121.13
(0-.40)
.184.44
(0-1.0)
.651.44
(0-.90)
.034.03
(0-.10)
.02
(0-.10)
Total
A. iricolor
n-23
.554.42
(.10-1.0)
.254.28
(0-.60)
.104.05
(0-.30)
.074.06
(0-.10)
.02
(0-.20)
.01
(0-.20)
0
16 Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 3. Lumbrineris zona
a. Fecal pellet content. Breakdown by
component into mean, standard deviation and range. Worms
were collected from different tidal zones in Phyllospadix
roots from the east shore of Mussel Point.
0
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 3. Lumbrineris zonata fecal pellet contents. To supplement
Figure 4.
Collection
tidal zone
-2
worms in
20
25
sample
.214-45
.614.10
.291.46
.094.16
.591.65
Endocladia
(O-1.0)
(0-1.0)
(0-.5)
5-.7)
(0-1.0)
Other red
.34+.40
.484.51
.284.23
.264.28
.584.60
(0-1.0)
(0-1.0)
(0-1.0)
(0-1.0)
(0-.5)
algae
Phyllospadis
040
.404.45
.064.12
.054.21
.014.07
(0)
(0-.90)
(0-.50)
(O-1.0)
(0-.25)
040
040
040
040
Blue-green
.014.03
(0)
(0-.06)
(0)
algae
(0)
(0)
.081.13
.121.20
Sand
.014.02
.014.05
.164.32
(0-.95)
(0-.03)
(0-.40)
(0-.50)
(0-.63)
.024.04
.084.20
Detritus
.014.02
.034.09
.074.22
(0-.37)
(0-.30)
(0-.05)
(0-.10)
(0-.35)
.034.06
.014.03
.05.16
.104.21
.054.10
Animal
(0-1.0)
(0-.20)
(0-.25)
(0-.85)
(0-.67)
material
040
Other
040
040
.034.11
040
(0-.40)
(0)
-plant
(0)
(o)
(0)
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
For L. zonata the contents of fecal pellets varied widely, both
between collection groups and among worms of the same collection group.
Even consecutive pellets from a single worm showed high variability.
But in all cases the fecal content was primarily plant material, the
majority consisting of red algae. It is interesting to note that
Hildenbrandia and Peyssonellia were found in the pellet contents.
These are encrusting algae which the worm had to scrape off the sub-
strate to ingest. Cross-sections of algae in the pellets suggested
that plant material had been bitten or scraped off, rather than taken
in as detritus.
Arabellids are generally considered to be carnivorous (Pettibone,
1963; Day, 1967). The well digested animal material, the presence of
sulphur bacteria, (very common on decaying animal material in the sea,)
and the lack of hard parts in the feces further suggest the worms are
carnivorous scavengers. Arabellids were never seen to eat carrion in
the lab, however. The consistently low percentage of detritus in the
gut indicates a high degree of selectivity towards preferred animal
foods.
L. zonata is unquestionably herbivorous, in complete contrast to
earlier literature which names all Lumbrineris species as carnivores
(Pettibone, 1963; Day, 1967). Although the worms live among Phyllo-
spadix roots, where a wide variety of both animal and plant matter is
available to eat, they appear to be feeding selectively on red algae.
TYPES
E BEHAVIOR
During our various investigations, several types of behavior were
noted. Some observations were made, under a dissecting microscope,
19
P. Mark, E. Whitaker
Feeding and behavior of polychaetes
of worms in glass bowls filled with sea water; other observations
were made of worms in narrow, glass sided aquaria.
Distinct locomotory behaviors were observed and seemed to be the
simple subunits of more complex behaviors which included feeding,
territoriality and search behavior. The different behaviors noted are
defined and discussed in the following paragraphs. Separate sections
on lumbrinerids and arabellids are included only where striking dif-
ferences were noted.
Locomotor activity of any sort in arabellids and lumbrinerids is
accompanied by the secretion of mucus from the anterior end of the
animal, presumably the prostomium. The mucus is pulled back poster-
iorly by parapodial movement as the worm moves, coating the entire
body. The rate of secretion and movement of mucus varies with worm
activity. Permanent or semi-permanent burrows are constructed when the
mucus adheres to the substratum, usually either sand or silt, main-
taining and open passageway.
All locomotory behaviors subsequently described involve setal
movements, therefore mention of setal types and their use is here
made. Both lumbrinerids and arabellids have limbate setae. They
appear throughout the length of the body in arabellids, but in lum-
brinerids they occur only anteriorly, with hooded hooks appearing
posteriorly. Limbate setae are well adapted for a mucus tube existence.
They hold the tube sides firmly, and also perform well in locomotion
outside of the tube. The hooded hooks of the lumbrinerids are ex¬
tended perpendicularly when the animal is alarmed, holding it tightly.
in its tube. Arabellids show a similar response in alarm, both in
and out of the tube. The body contracts and coils to hold its posi¬
tion within the tube.
Feeding and behavior of polychaetes
P. Mark, E. Whitaker 20
Locomotory Behavion
1. Burrowing in all species studied involves forward peri-
staltic movement of the anterior portion of the body, directed by
the prostomium. The parapodia in the mid and posterior portions are
extended monotaxisally and provide anchorage.
2. Reverse peristalsis is a rapid reversal of the burrowing
movement. It is often seen when a worm receives an aversive stim¬
ulus anteriorly.
3. Crawling is a ditaxic "walking" motion. It is used in
preburrowed tubes or on the surface of a substratum.
4. Backing up is essentially crawling in reverse.
5. Turning around involves bending the body double and crawl-
ing with the parapodia making a "U" turn within a mucus burrow.
6. Nosing around is an exploratory movement performed by
worms especially when they protrude the anterior end out of the burrow.
A worm iifts its prostomium and first few segments off the substratum
and moves this portion slowly side to side in a "searching" manner.
7. Ventilation (?) or side-to-side movement is a lateral
undulation of the body within a burrow. It appears to be accomp¬
lished by forcefully extending the setae and parapodia out laterally
on one side while retracting them on the opposite side. The action
occurs in waves traveling along the body so that if at any instant
the worm was frozen it would look like a sine wave.
Defecation
Feces are eliminated in discrete pellets.
Defecation was rarely observed under natural conditions. However,
L. zonata in its burrow was once seen to back up till the anus was
at the burrow entrance and to defecate outside of the burrow.
P. Mark, E. Whitaker
Feeding and behavior of polychaetes
Feeding and proboscis eversion.
Polychaetes of both
families have well developed, hard jaw parts used in feeding.
(Figure 5.) Proboscis eversion and subsequent behavior was observed
on several occasions in the laboratory. In proboscis eversion, the
prostomium is raised, the circular muscles of the first two segments
are relaxed, and the circular muscles in segments 3, 4 and 5 con¬
tract, forcing the pharynx out. As the pharynx protrudes, the jaw
parts spread out laterally, until, at full extension, the jaws are
fully open. This eversion is accompanied with a slight backward
movement. Next comes a forward lunge, closure of the jaws, and in-
version of the proboscis. The worm retracts quickly, tearing off a
piece of whatever it has bitten. This general action, used in feed-
ing in both families, and in territorial behavior in arabellids, was
seen on six occasions.
The basic action may be modified in two ways. In one method,
seen once in A. iricolor,tthe jaws were fully everted and the worm
was seen to scrape them along Phyllochaetopterus tubes. In the other
method, seen twice in both A iricolor and lumbrinerids, the pro-
stomium was partially everted, exposing the forceps (maxillae 7)
and several of the other plates. The forceps opened laterally, g
grabbing and ripping off pieces of food material.
Attempts were made to elicit feeding responses in both lumbri-
nerids and arabellids using potential foods, both whole and ground.
No feeding responses were seen. Mangum and Cox (1971) noted a feed-
ing response elicited by homogenates of possible food items. A
similar method was attempted with tubiculous arabellids, but no
discernible feeding response was seen.
0
22
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Figure 5. Jaw parts and proboscis eversion. Arabella and Lumbrineris.
a. A. semimaculata. dorsal view of jaws. b., c. A. semi-
maculata. views of anterior end with pharynx extended.
d. A. iricolor. dorsal view of jaw parts, after Blake (1975).
e. Lumbrineris latreilli. dorsal view of jaws, after Blake
(1975). f. Lumbrineris fragilis. everted proboscis showing
jaws, ventral view, after Pettibone (1963). I-V, maxillary
plates; mo, maxillary carriers; mand, mandibles; mp,
median piece.
22
Feeding and behavior of polychaetes
mand

SE
mp.
mc.

mand

-IV

L


—me
en
FIGURE 5
P. Mark, W. Whitaker
5

1






23
Feeding and Behavior of polychaetes
P. Mark, E. Whitaker
24
Territorial Behavior
On several occasions throughout the study arabellids were obser-
ved displaying territorial behavior in protecting the home areas right
around their burrows. To facilitate study and elicit more aggressive
displays, both species of arabellids were introduced into glass capil-
lary tubes where they established themselves for several days. Any
attempt to manipulate the worms or tubes to optimize aggression were
not successful.
A general behavioral sequence based on five occurrences is postu¬
lated for territoriality. Three of five times a free living worm
wandered to within four to five cms. of an established tubiculous
arabellid. Continued movement of the invader and the home worm
brought both worms to within about one cm. of each other. At about
this distance theyworms seemed to sense one another and withdrew a
short distance. Then, only the home worm everted its jaws and made
a well aimed lunge at the other worm. After the lunge, which may or
may not culminate in an effective bite (one of five times the attack
caused a tear in the body wall of the trespassing worm,) both worms
withdrew, after which the invader left.
Tubiculous behavior
Overall observations were made on the tubiculous living habits
of all species.
Each arabellid placed in narrow aquariumcontaining a cluster of
Phyllochaetopterus tubes established a semi-permanent system of mucus
burrows with multiple openings to which it returned after foraging.
Worms in the same aquarium never shared burrows. Indeed, all ara¬
bellid burrow systems seemed to be completely autonomous and inde¬
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
pendent of the burrows of other arabellids. This correlates well with
their territorial behavior.
Within sand filled aquaria each L. zonata constructed an inter-
connected system of burrows throughout the sand. Most sets of burrows
had at least one opening to the surface. These worms often used pre¬
existing burrows, and in so doing frequently encountered one another.
No aggression between lumbrinerids was ever noticed. The worms either
turned around, backed up or burrowed in another direction. In con¬
trast, two L. erecta placed in the same sand filled aquarium establish-
ed U-shaped burrows with both ends open to the surface. During the
observed two week period, both L. erecta spent about 95% of the
time in the top one third of the sandy layer. Occasionally each worm
nosed around on the surface or burrowed some distance, but generally
both remained in or returned to the site of the original burrow.
Reproduction and Regeneration
Spawning behavior was seen once in L. erecta. Eggs were visible
through the the body wall. They appeared to be shed through the body
wall. They appeared to be shed through ducts between the pre-and post¬
setal lobes of the parapodia. The eggs, when shed, were loose, not
contained in gelatinous masses.
Up to 70% of arabellids collected whole showed evidence of pos¬
terior regeneration; a lighter pigment in the posterior 30-40 setigers.
Noting this, a small-scale regeneration experiment was started using
A. iricolor. Six whole worms were selected. From four the anterior
40 setigers were excised, from the remainder the last 40 setigers
were removed. After one week all the posterior ends had died. At
the end of four weeks a presumed pygidial bud had formed on one worm.
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Many lumbrinerids collected had small regenerated pygidia and
posterior segments.
24 Hour Behavioral Observation
To better observe the behavior and general "living habits" of
the arabellids and lumbrinerids, narrow glass sided aquaria were
set up to simulate their respective natural habitats while allow-
ing us to see them. For the arabellids, three aquaria, 35 cm.x
30 cm. x 2 cm. were loosely filled with Phyllochaetopterus prolifica
tubes and the related small organisms obtained from the collection
site at the marina. A similar aquarium, only.4 cm. thick, was
filled with fine sand for the lumbrinerids. All aquaria were main-
tained with fresh running sea water at 12-13° C. and kept under a
dark cover to minimize behavior related to light sensitivity.
Systematic observations, which would be statistically treatable,
were made over a 24 hour time period. It was hoped that these ex-
tended observations would allow observations of low frequency behav¬
ior, activity as related to time of day, correlations between behav-
ior and possibly periodicity. A check sheet was devised to record
location, orientation and behavior for each worm at five minute
intervals. (Table 4.)
The gathered data were initially averaged to note the amount of
time each worm spent engaged in each activity. Hourly averages of
activities were also plotted over time to detect any trends in act¬
ivity as correlated to time of day or periodicity. No plots of this
sort yielded any meaningful correlations so time periods were grouped
in four hour blocks. In this analysis the midday shift for both
Arabella species was shown to be significantly more active than
26
27 Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 4. Sample check sheet used for systematic, in lab observations
of worms in 24 hour observations.
— 1—

8

Feeding and
behavid
of polychaetes
P. Mark, E. Whitaker
TABLE4.
—...








t-

L
—



28

2

g
8



+in
——
—
—


O
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
either the previous or subsequent time blocks (p°.005.) Tabulated
results are found in Table 5. Equivalent analyses for both Lumbri-
neris species showed no significant difference in activity level for
any four hour period.
p
DISCUSSION
Several features of A. iricolor and A. semimaculata discovered
in the course of this investigation contribute to a picture of the
life of these worms.
Arabella iricolor and A. semimaculata are tubiculous worms that
live in large numbers in wharf piling and harbor float communities.
The tubes are made by peristaltic burrowing and consolidated with
mucus. Arabellids have limbate setae adapted for grasping a mucus
tube.
The worms forage for their food during the day, merely extend¬
ing their anterior ends or entirely leaving the burrow and returning
to the same burrow for the bulk of the day. Tube systems are auto¬
nomous and worms do not share burrows. In fact, territorial protec¬
tion of tube and foraging area have been observed.
In the daylight feeding expeditions the worms selectively eat
animal carrion. Differences in the diet of A. iricolor and A. semi¬
naculata are statistically significant and may be indicative of
parameters that separate two worms that live in the same habitat and
are by all indications very similar.
Based upon fecal pellet contents, behavioral observations in the
laboratory, and observations made on Phyllospadix root clusters when
the worms were collected, a living "pattern" for L. zonata can be
reconstructed. The system of burrows constructed in the sand aquar¬
iums supports the idea that in natural conditions the worms have
5
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Table 5. A. iricolor and A. semimaculata. Species dependent activity
versus time (in four hour blocks.) Recording the number of
observations the worms were active and inactive in these time
blocks. Used in RX C - G test. (n-total number of obser-
vatiens.
30
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Feeding and behavior of polychaetes
Table 5.
Time
Arabella iricolor
(24 hr. scale)
Active
Inactive
1-5
62
72
n=360
5-9
30
132
n=360
9-13
110
n=540
13-17
26
n=720
17-21
63
n=540
63
21-1
82
n=900
P. Mark, E. Whitaker
Arabella semimaculata
Active
Inactive
36
27
29
72
62
46
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
a similar, though more extensive tube system beneath the Phyllo-
spadix roots. The animals are unquestionably herbivores, which ap-
pear to ingest their food in sizeable "bites." At least occasion¬
ally they scrape encrusting algae such as Hildenbrandia and Peysso-
nellia from the rocks. This information, derived from fecal pellet
analysis, in conjunction with one observation of feeding and a
knowledge of jaw parts, leads one to conclude that the worms are
browsers, emerging from their tubes to take in living plant material
and detritus from the immediate vicinity.
A comparison of the distribution, feeding and observed behavior
of the four species studied reveals striking differences in many
respects. With regard to habitat, both arabellids were mainly found
in a subtidal environment, in protected burrows in calm water. Both
lumbrinerids were found intertidally, L. zonata being much more
abundant than L. erecta. Possibly L. erecta is primarily subtidal.
As striking a difference was seen in feeding. Arabellids are
carnivorous scavengers and defend their home grounds. Lumbrinerids
are browsing herbivores and do not defend territories.
SUMMARY
1. Arabella iricolor and Arabella semimaculata were found in
moderate numbers in Phyllochaetopterus tube communities at wharf
72 and the Monterey marina and in tunicate clusters at the marina.
Infrequently an A. iricolor was found in Phyllospadix roots at
Mussel Point. in the low intertidal zone (O to -2 ft.).
2. Lumbrineris zonata was found abundantly intertidally (O to
-2 ft.) at Mussel Point. L. erecta was found more rarely in the same
habitat. Neither species was found at the wharf or marina.
32
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
3. A. iricolor and A. semimaculata are apparently carnivorous
scavengers. Fecal pellet contents revealed 65% digested animal m
material and 15% sulphur bacteria.
4. L. zonata and L. erecta are herbivore, ingesting predomin-
antly red algae in "bites" as revealed by fecal pellet analyses.
5. Both Arabella species live in individual systems of semi-
permanent mucus burrows next to the site of attachment of the Phyllo¬
chaetopterus tubes and clusters of tunicates. The worms do not share
burrows, and do show aggressive territoriality.
6. The Lumbrineris species live in a system of semippermanent
mucus burrows in the sand under Phyllospadix roots. Evidence from
behavioral studies indicated that the worms are probably browsers.
No aggressive behavior was seen.
33
Feeding and behavior of polychaetes
P. Mark, E. Whitaker
REFEE
NCES
Blake, J.A. 1975. Phylum Annelida: Class Polychaeta, p.151-243.
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University of California Press, Berkeley and Los Angeles. 716 p.
Dales, R.P. 1962. The polychaete stomodeum and the inter-relation-
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Dales, R.P. 1967. Annelids. 2nd ed. London: Hutchinson. 200 p.
Day, J.H. 1967. A monograph on the Polychaeta of Southern Africa.
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Fauchald, K. 1970. Polychaetous Annelids of the families Eunicidae,
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Hartman, O. 1944. Polychaetous Annelids:fPartCV.iEunicia.-Allaneg
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Pettibone, M.K. 1977. Endoparasis
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Feeding and behavior of polychaetes
P. Mark, E. Whitaker
Pettibone, M.H. 1957. Endoparasitic polychaetous annelids of the
family Arabellidae with description of new species. Biol. Bull.
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Pettibone, M.H. 1963. Marine polychaete worms of the New England
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P. Mark, E. Whitaker
Feeding and behavior of polychaetes
ACKNONLEDGEMENTS
Our sincere thanks to Dr. D. P. Abbott for his patience and
invaluable assistance.
And to Dr. Isabella Abbott for help with all those fecal pellets!
Honorable Mention: Dr. Robin Burnett, whose help was definitely
sigtistically stagnificant.