POPULATION CHARACTERISTICS O F THE CRAB
MONODAEUS COUCHII (CRUSTACEA, BRACHYURA,
XANTHIDAE) I N T H E WESTERN MEDITERRANEAN
Mori, M., Abelló, P., Mura, M. & De Ranieri, S., 1995. Population characteristics of the crab
Monodaeus couchii (Crustacea, Brachyura, Xanthidae) in the Western Mediterranean. Misc.
Zool., 18: 77-88.
Population characteristics of the crab Monodaeus couchii (Crustacea, Brachyura, Xanthidae)
in the Western Mediterranean.- Some aspects of the biology of the bathyal crab Monodaeus
couchii from the North Tyrrhenian Sea, Sardinian Channel and Catalan Sea (Western
Mediterranean) have been studied. The occurrence depth range has been found to be of between 8 0 and 748 m. The sex-ratio was found to be highly biassed towards males in the three study
areas. The crabs are sexually dimorphic, adult males being larger than adult females. There
appears to be seasonality in reproduction: ovigerous females were only collected in October,
November and December. Puberty moult, as determined by morphological changes of the chelae, takes place in males within a size range of 11-16 mm carapace length. This species is heterochelic, with most males being right-handed. M. couchii is an opportunistic predator but seems
to be also able of deposit feeding and scavenging.
Key words: Brachyura, Xanthidae, Monodaeus, Distribution, Population biology.
(Rebut: 11 XI 94; Acceptació condicional: 21 11 95; Acc. definitiva: 27 VI1 95)
Mario Mori, Istituto di Anatomia Comparata delllUniversita, viale Benedetto XV 5, 16132
Genova, Italia (1talyJ.-Pere Abelló, Institut de Ciencies del Mar (CSIC), Passeig Joan de
Borbó s/n., 08039 Barcelona, Espanya (Spain).- Marco Mura, Dipartimento di Biologia
Animale ed Ecologia, Universitd degli Studi di Cagliari, Viale Poetto 1, Cagliari, ltalia
(Italy).- S. de Ranieri, Dipartimento di Scienze delllAmbiente e del Territorio dell'Universita,
via A. Volta 6, 56100 Pisa, Italia (Italy).
The Italian part of this research was supported by the Ministero Marina Mercantile. Data from
the Catalan Sea were obtained through the research programs "Análisis de la degradación de
comunidades explotadas" funded by CAICYT, and "Estudi de l'impacte de la pesca dels arrastrers petits en els stocks d'espkcies comercials de la costa catalana" funded by Generalitat de
Catalunya.
INTRODUCTION
Monodaeus couchii (Couch, 1851) is a deepwater crab which inhabits muddy substrates
on the outer shelf and continental slope. Its
distribution area encompasses the
Mediterranean and Eastern Atlantic from
&
Scotland southward to Angola (MANNING
HOLTHUIS,
1981; CLARK,1986; INGLE,1981).
Published information on its biology is
limited, especially because of its low densities and therefore scarce records. However, it
1
l
Misc. Zool. 18, 1995
Fig. 1. Location of the three study areas in the western Mediterranean. A. Thyrrenian Sea; B. Sardinian
Channel; C. Catalan Sea.
Situación de las tres zonas de estudio en el Mediterráneo occidental. A. Mar Tirreno; B. Canal de
Cerdeña; C. Mar Catalán.
is not a rare species, since it is preyed upon
by many epibenthic species of the bathyal
Mediterranean, such as the crabs Geryon longipes and Paromola cuvieri (RELWI& MORI,
1977; MORI,1986), and the fishes Chimaera
monstruosa, Galeus melastomus, Phycis
blennoides, and Conger conger (VACCHI
&
RELINI,1979; MACPHERSON,
1980; RELINI&
FANCIULLI,
1981; MORI,1982).
The present investigation was set out to
analyse the main population characteristics of
Monodaeus couchii, such as depth range of
distribution, population structure, reproductive biology, morphometrics and diet from data
collected on its populations from the Northem
Tyrrhenian Sea, Sardinian Channel and
Catalan Sea in the Westem Mediterranean.
MATERIAL AND METHODS
Crabs were collected from three study areas:
the North Thyrrenian Sea between the islands
of Elba and Giannutri, the Sardinian Channel
between Sardinia and Tunisia, and the Catalan Sea off the coasts of Catalonia (fig. 1).
A total of 86 males and 19 females were
collected from the Thyrrenian Sea during six
years of demersal trawl surveys (1985-86-87
and 1990-91-92) in the area lying between
the islands of Elba and Giannutri. A total of
260 hauls were performed with a 20 mm
mesh trawl net, within a depth range of 4635 m. Sarnples were taken in al1 months of
the year. In the Sardinian Channel a total of
50 females and 115 males were collected in
MORI et al.
30 trawls from depths of between 400 and
550 m in June-December 1993 using 20 mm
mesh size trawl nets. Data from the Catalan
Sea were collected dunng two fishery research surveys with monthly samples performed between June 1981 and June 1983 and
between November 1990 and November
1991 off the coasts of Catalonia. In 1981-83,
a total of 185 trawls were completed in
depths of between 3 and 871 m using bottom
trawl nets of 20 rnm mesh size equipped with
a 9 mm mesh size covered codend. In 199091,66 trawls were performed at depths comprised between 16 and 677 m. A total of 125
male and 49 female of Monodaeus couchii
from this area were collected and examined.
Measurements were taken with vernier
calipers to the nearest 0.1 rnrn. Data collected
were: CL. Carapace length, from the frontal
margin to the posterior edge of the carapace;
CW. Carapace width, from tip to tip of the last
anterolateral teeth; handedness; in right-handed individuals; RCRL. Crusher chela propodus length, right crusher length, from the
ventral carpo-propodus junction to the tip of
the chela and RCRH. Crusher chela propodus
height, maximum height of the propodus at the
leve1 of the dactylar junction. A distinction
was made in male crabs between those bearing
a closed chela (juveniles) and those bearing an
open chela (adults). Morphometric data were
analyzed by calculating the linear regression
of log CW, log RCRL and log RCRH on log
CL (Model 1). Allometry was determined by
comparing the slope of the log-transformed
regressions with the isometxic slope of 1 using
the Student's t-test. Hystological exarnination
of the vas deferens of three juvenile and five
adult male crabs from the Thrrenian Sea was
performed to relate externa1 morphology of
the chelae with the onset of sexual matunty.
Natural diet was determined by foregut
content analysis of 24 males from the
Thyrrenian Sea and of 74 males and 33 fema-
les from the Sardinian Channel. Al1 the crabs
studied were collected in summer, during
daytime, within a depth range of 400-500 m.
Food items were scored using the percentage
occurence method (F%) as described by
WILLIAMS
(1981); in the samples from the
Sardinian Channel the percentage number of a
prey in relation to the total prey number (N%)
was calculated for those prey items in which
quantification was posible. Empty foreguts
were omitted from al1 calculations. To test for
differences in the proportional constitution of
stomach contents of males and females from
the Sardinian Channel, a chi-squared test was
performed on the frequency of occurrence of
the different prey categones (SIEGEL,1956).
RESULTS
Bathymetnc distribution
In the Northem Thyrrenian Sea, specimens of
Monodaeus couchii were collected within a
depth range of 80-635 m; the sampled depth
range was 4-635 m. In the Sardinian Channel
M. couchii occurred at depths of between 400
and 600 m; the sampled depth range was 100600 m. The depth range of occurrence of M.
couchii off the coasts of Catalonia was found
to be 137-748 m; the sampled depth range
was 3-871 m.
Size population structure and sex-ratio
In the Thyrrenian Sea, the size of the individuals collected (86 males and 19 females)
ranged between 5.5 and 21.2 mm CL for
males and between 8.3 and 13.9 mm CL for
females (fig. 2). Both juvenile and adult
males occurred in the catches, while most of
the females were adult individuals (the smallest ovigerous female sampled was 11 mm
CL; see below). In the Sardinian Channel,
male sizes ranged between 8.8 and 21.1 mm
CL. and female sizes between 8.4 and
Misc. Zool. 18, 1995
Thyrrenian Sea
Males
Females
7
6
5
2E 4
L3
2
1
o
5
1O
15
20
25
5
Carapace length (mm)
1O
15
Sardinian Channel
Males
20
25
Carapace length (mm)
20
Females
14
12
15
10
L
a
n
$ 8
;10
2
z
6
5
4
o
o
2
5
1O
15
20
25
5
Carapace length (mm)
1O
15
15
20
Carapace length (mm)
20
25
Carapace length (mm)
Catalan Sea
Males
5
10
25
5
Females
10
15
20
Carapace length (mm)
25
MORIet al.
15.8 mm CL (fig. 2). In the Catalan Sea, sizes
ranged between 9.4 and 22.0 mm CL for
males, and between 8.0 and 16.6 mm CL for
females (fig. 2). Al1 crabs were captured within tlíe codend. As in the Thyrrenian Sea,
most of the females captured were adult individual~(the smallest ovigerous female sampled was 10 mm CL; see below). In al1 the
areas studied, the d e population was markedly bimodal or polymodal, whereas the
female population was clearly unimodal. The
size range and the population structure were
similar in the three populations studied.
The overall ma1e:female sex-ratio found
in the Thyrrenian Sea was 4.5:1, in the
Sardinian Channel, 2.3:1, and in the Catalan
Sea, 2.6:l. In the three populations studied
males occurred more frequently in the catches than females. The sex-ratio at sizes larger than 15 mm CL was however clearly
dominated by males.
Reproductive biology
Only three ovigerous females weré collected
in the Thyrrenian Sea; they measured 10.8,
11.3 and 13.9 mm CL and were collected in
October and November 1991, and December
1992 (fig. 2). Two out of three females
collected in May-June 1992 had mature
gonads of an orange colour. In the Catalan
Sea, ovigerous females were only collected
in three trawls performed in November 1990,
and their sizes ranged between 10.3 and
13.6 mm CL (fig. 2); in November 1991, two
Table 1. Occurrence of a hydroid, living in epibiosis on the carapaces of Monodaeus couchii, and of a sacculinid parasite in the different study areas in the Western Mediterranean.
Presencia de un hidrozoo epibionte del caparazón de Monodaeus couchii y de un parásito saculínido
en las distintas áreas de estudio en el Mediterráneo occidental.
With hydroids
With parasite
Thyrrenian Sea
Adult males
Juvenile males
Total males
Adult females
Catalan Sea
Males
Females
Sardinian Channel
Males
Females
Overall
Males
Females
Fig. 2. Size frequency distributions (CL, in 1 mm size classes) of male and female Monodaeus couchii.
Distribuciones de frecuencias de tallas (CL, en clases de talla de 1 mm) de machos y hembras de
Monodaeus couchii.
81
Misc. 2001.18, 1995
out of six females had fully mature gonads of
a violaceous colour. In the Sardinian
Channel one ovigerous female of 15.5 mm
CL was collected in December 1993, whereas 46% of the 39 females collected in JuneJuly 1993 had yellow-orange developing
ovaries and none had mature violaceous
gonads.
Epizoites and parasites
The presence or absence of colonies of a
hydroid epibiont on the carapace of the crabs
was noted for a total of 55 males and 15
females in the Thyrrenian Sea and for 32
males and 18 females in the Catalan Sea
(table 1). This hydroid has been identified as
Opercularella panicula (G. O. Sars, 1874). It
was mainly located on the bases of the
pereiopods and on the lateral and posterior
margins of the carapace. More than half the
adult males examined in the Thyrrenian Sea
had hydroid colonies growing on them, while
a much smaller proportion of juvenile crabs
carried epibionts (table 1). Only two of the
male crabs exarnined in the Catalan Sea had
colonies of this hydroid.
The occurrence of externae of a sacculinid parasite was noted in some of the crabs
studied (table 1). No parasitized crabs were
found in the Thyrrenian Sea. The infestation
prevalence was however low in the other
populations studied (3.5-8.0%).
Handedness
The percentages of the different handedness
types found in males and females in the three
areas studied are shown in table 2.
Monodaeus couchii is a heterochelous crab,
with most individuals (around 88%) being
right-handed, i.e. the right chela has a crusher
morphology and the left, a cutter. The major
chela (crusher) is different in shape from the
minor one (cutter), and has large molariform
teeth at the base of propodial claw.
Table 2. Percentage of crabs with one or both chelae rnissing, and of the different handedness types (nghthanded (RH), left-handed (LH), and homochelous), in male and female Monodaeus couchii in the three
study areas. Only individuals with both chelae present have been taken into account to study handedness.
Porcentajes de pérdida de quela y de tipos de lateralidad en machos y hembras de Monodaeus
couchii de las tres áreas estudiadas: RH. Pinza robusta en la derecha; LH. Pinza robusta en la izquierda. Para el estudio de la lateralidad en las quelas sólo se han tomado en consideración aquellos individuos con las dos quelas presentes.
RH
Thyrrenian Sea
Males
Females
Catalan Sea
Males
Females
Sardinian Channel
Males
Females
Overall
Males
Females
LH
Homochelous
%RH
MORIet al.
MorphometricsAll morphometric relationships were first studied by sex and area separately. Significant differences were only
found between sexes, not between areas.
Data were therefore grouped.
Table 3. Pameters of the potential regression
equations (y = a xb) in male and female
Monodaeus couchii for carapace length (CL) and
carapace width (CW) (in rnrn).
Parámetros de las ecuaciones potenciales de
regresión entre la longitud de cefalotórax (CL) y
la anchura de cefalotórax (CW) (en mm) en
machos y hembras de Monodaeus couchii.
a
b
r
n
Comparison
Ho
t
Significance
Allometric status
Males
Females
0.3482
1.016
0.9865
252
0.2752
1.055
0.9705
117
b=l
1.50
n. s.
Isometry
b=l
2.25
p < 0.05
Allometry (+)
The parameters of the relationship between carapace length (CL) and carapace width
(CW) are shown in table 3. A significant
positive allometry was found in carapace
shape in females. Females would accordingly
enlarge their body in width more than in
length with size.
The relationship between carapace
length and chelar propodus length and
height has been studied in both sexes in
right-handed individuals, i.e. those with a
right crusher chela, in order to detect any
possible change in allometry with size. The
morphological change in cheliped shape
between juvenile and adult crabs started at
around 11 mm of carapace length; juvenile
crabs, with closed chelae, were found up to
a size of 16.0 mm CL, whereas crabs with
open chela morphology ranged between
11.2 and 22.0 mm CL. Regressions were
estimated separately for crabs with open and
closed chelae (table 4). The hystological
examination of the vas deferens of juvenile
and adult male crabs confirmed that this
change in chela morphology coincided with
Table 4. Parameters of the potential regression equations (y = a xb) between size (CL, in mm) and nght
chela propodus length (RCRL) and height (RCRH) in right-handed male and female Monodaeus couchii.
Parámetros de las ecuaciones potenciales de regresión entre la talla (CL, en mm) y la longitud
(RCRL)y anchura (RCRH)del propodio de la quela derecha en machos y hembras de Monodaeus couchii
con la quela derecha robusta.
-
-
-
a
b
r
n
t
Significance
Allometric Status
RCRL
Males closed
Males open
Females
-0.251
-0.589
-0.292
1.143
1.281
1.127
0.975
0.963
0.953
81
139
80
4.88
9.18
3.12
p < 0.001
p < 0.001
p <0.01
Allometry (+++)
Allometry (+++)
Allometry (++)
RCRH
Males closed
Males open
Females
-0.970
-1.391
-0.953
1.109
1.289
1.057
0.932
0.933
0.908
75
133
76
2.16
6.66
1.00
p < 0.05
p < 0.001
p > 0.05
Allometry (+)
Allometry (+++)
Isometry
Misc. Zool. 18, 1995
Males clearly reach larger sizes than
females (MURA,1987; present results) and
occurred more frequently in the samples in
the three populations studied. This rnay be a
characteristic of the population, but it rnay
Diet
also be due in part to an artifact of trawl
The foregut contents of 24 male crabs from
selectivity, since females are smaller than
the Tyrrhenian Sea was investigated. Only
males and rnay escape more often the samnine of them were found to be empty. Of
pling gear. This size difference rnay help in
the remaining, three had full foreguts and
any potential protective role of the male
12 were at least one-fourth full. Bivalves
towards
the female versus predators and male
were present in 60% of the samples examicompetitors dunng mating.
ned, with gastropods, ophiuroids and peraSpawning in the Western Mediterranean,
carid Crustacea occurring l e s ~frequently
according to present results, takes place in
(table 5).
autumn-winter. No author has ever recorded
The diet of crabs from the Sardinian
ovigerous females of Monodaeus couchii in
Channel was examined in 74 males and 33
spring or summer in the Mediterranean. In
females, of which 16 males and 6 females
the Atlantic, however, ovigerous females
had empty foreguts. There were no differenhave been observed between April and June
=
ces in diet composition between sexes
(INGLE,1981). The scarcity of ovigerous
6.4; p > 0.5); data were therefore combined
females in the samples rnay be due to their
for both sexes. Crustaceans and polychaetes
remaining in their burrows during the eggconstituted the most important prey based
carrying period, thus being inaccesible to
both on presencelabsence data and as number
trawling, as seems to be the case of other
of prey (table 5).
deep-sea crabs such as Geryon trispinosus
(ATTRILL
et al., 1991).
The results regarding size at sexual maturity
DISCUSSION
estimated from morphometric data in male
Monodaeus couchii showed that maturity startThe normal distribution depth range of
ed within a size range of 11-16 mm CL.
Monodaeus couchii is comprised between
Morphology
of the chelae in crabs is very
around 60 m to at least 1300 m (ZARIQUIEYimportant
for
a
wide variety of behavioural inte& HOLTHUIS,
ÁLVAREZ,1968; MANNING
ractions such as feeding habits, agonistic inte1981; INGLE,1981). In the Mediterranean,
ractions and courtship behaviour (HARTNOLL,
the populations of M. couchii are found on
1982; VANNINI
& GHERARDI,
1988).
muddy substrates on the outer shelf and,
Monodaeus couchii can be considered as a
especially, on the upper and middle slope
right-handed species. Most xanthid crabs are
(MURA,1987; A B E L Let
~ al., 1988).
known to be major predators of molluscs
However, some records have been reported
1977) and NG & TAN(1985) propoat shallower depths in the Atlantic by INGLE (VERMEIJ,
sed that nght-handedness rnay be related to the
(1981) and in the Mediterranean by
fact that almost al1 marine gastropod shells are
PASTORE
(1981), who reported this species
dextral. However, the analysis of the feeding
at 7 m on Modiolus beds and at few centihabits
of M. couchi shows that it is not a spemeters on the seaweed Cystoseira spp., rescialized
gastropod predator, but an opportunispectively.
the onset of sexual maturity. No distinction
was made in female crabs according to chela
morphology.
(x2
MOR[et al.
Table 5. Diet of Monodaeus couchii from the Sardinian Channel(6 6 n = 58; Q Q n = 27) and Northem
Thyrrenian Sea ( d n = 15). F%. Percentage occurrence of a prey; N%. Percentage number of a prey.
Dieta de Monodaeus couchii en el Canal de Cerdeña ( d d n = 58; Q Q n = 27) y norte del Mar
Tirreno ( d O' n = 15). F%. Porcentaje de presencia de una presa; N%. Porcentaje en número de una
presa.
Sardinian Channel
Females
Males
Crustacea
Decapoda
Sergestes sp.
Plesionika sp.
Natantia unidentified
Calocaris macandreae
Ebalia sp.
unidentified
Brachyura
Amphipoda
Lysianassa
unidentified
Isopoda
Cirolana borealis
unidentified
Cumacea
Leucon sp.
unidentified
Copepoda
unidentified
Unidentified
Total
Males
F%
N%
F%
N%
F%
N%
1.7
3.4
1.7
3.4
1.7
1.7
4.3
4.3
2.2
4.3
4.3
2.2
3.7
4.3
3.7
8.7
2.3
2.3
1.2
3.5
1.2
1.2
4.3
2.9
1.4
5.8
2.9
1.4
3.4
5.1
4.3
8.7
3.7
7.4
4.3
8.7
3.5
5.8
4.3
8.7
3.4
8.6
4.3
10.9
3.7
11.1
4.3
17.4
3.5
9.4
4.3
13.0
3.4
4.3
17.2
21.7
3.7
3.7
3.7
18.5
4.3
4.3
8.7
21.7
1.2
3.5
1.2
17.6
1.4
4.3
2.9
21.7
F%
13.3
Mollusca
Bivalvia
Nucula sp.
unidentified
Gastropoda
1.7
1.7
2.2
2.2
Polychaeta
Nephtyidae
unidentified
3.4
12.1
4.3
15.2
Echinodermata
Echinoidea
Crinoidea
Ofiuroida
3.4
Foraminifera
Plas tic
Sediment
Marine Plants
Posidonia oceanica
N. Thyrrenian Sea
11.1
13.0
2.3
11.8
2.9
14.5
2.3
3.7
6.6
6.6
1.2
13.3
12.1
7.4
1.7
3.4
3.4
10.6
1.2
8.2
18.5
5.9
26.6
13.3
Misc. Zool. 18, 1995
tic predator. VANNINI
& GHERARDI
(1988)
observed that the growth of the chelae of the
xanthid crab Eriphia smithi did not differ between right and left-handed individuals, thus
suggesting a possible genetic determination of
handedness. In Callinectes sapidus
(HAMILTON
et al., 1976), Nephrops nowegicus
(SARDA,1983), and Menippe mercenaria
(SIMONSON,
1985), handedness changes with
age, i.e the crabs may al1 begin life with a right
crusher chela, but dunng their life cycle they
can lose chelae and as a consequence there is a
reversal of handedness. Al1 our left-handed
specimens were adult crabs, but, in agreement
with ABELLÓet al. (199O), a larger sarnple size
of juvenile crabs is necessary to confirm a
change with age.
A significant positive allometry was
found in carapace shape in females, which
would accordingly enlarge their body in
width more than in length with size, a fact
that may be related to an increase in carapace
volume which would allow more space for
ovaries to develop.
Monodaeus couchii in the Tyrhhenian
Sea feeds mainly on bivalves and crustaceans, while in the sardinian channel the
main prey are crustaceans and polychaetes'
The differences in diet composition between
the two Mediterranean populations may
reflect differences in prey species availability in the two areas, especially for
mO1luscs and other benthic
A
Part of identifiable food items in the
foreguts of M. couchii of the two populations
studied were organic partic.es. I~ deep-sea
sediments a significant proportion of
particles cOnsist 0f nanObiOtal
ments i.e. microorganisms between the size
of bacteria and meiofauna ( W A T L ~ G
1989).
,
~ h i ~ that M. couchii can also act as
a deposit feeder. Whether the
organisms are or are not a sufficient source
of energy for macrobenthic populations is
86
still a subject open to discussion (CAMMEN,
1989). Deposit feeding probably represents
an integration of the diet. Finally, the presence of unidentified organic debris confirmed
that M. couchii, as many other crabs
(WARNER,
1977), is also a scavenger. In conclusion, this species can be described, as
many other species of bathyal crabs such as
Geryon longipes, Paromola cuvieri and
Macropipus tuberculatus (RELINI& MORI,
1977; MORI, 1986; ABELLÓ,1989), as an
opportunistic predator which is also able to
switch between deposit and scavenger
feeding.
ACKNOWLEDGEMENTS
Thanks are due to al1 participants in these programs. We wish to thank Dr. J. M. Gili (ICM,
Barcelona) for the identification of the epibiotic
hydroid,
RESUMEN
Caracteristicas poblacionales del cangrejo batial
Monodaeus couchii ( C r u s t a c e a , B r a c h y ~ ~ r a ,
Xanthidae) en el Mediterráneo occidentnl,
Se han estudiado algunos aspectos de la biología del cangrejo Monodaeus couchii a partir de
ejemplares capturados en el mar Tirreno, canal de
Cerdeña y mar Catalán (Mediterráneo occidental)
(fig. 1). El rango batimétrico de distribución abarcó
profundidades comprendidas entre 80 y 748 m,
abarcando parte de la plataforma continental y el
talud superior y medio. Su presencia es no obstante
más común en el talud continental. La proporción
de sexos en las muestras se inclina claramente a
favor de los machos en las tres áreas de estudio. La
especie presenta dimorfismo sexual de tallas, alcanzando los machos tallas superiores a las de las hembras (fig. 2). Se detectó la presencia de hembras
ovígeras en octubre, noviembre y diciembre. Se
observó la presencia de un hidrozoo epibionte, así
como de un parásito saculínido (tabla 1). La especie
es heteroquélica, presentando la mayor parte de
ejemplares la pinza robusta en la derecha (tabla 2).
MORIet al.
Las hembras presentan una ligera alornetría positiva en la forma del caparazón (tabla 3). La muda de
pubertad, determinada por cambios morfológicos
en las quelas, tiene lugar en los machos a una longitud de cefalotórax estimada alrededor de 11-16
mm (tabla 4). Su dieta está basada fundamentalmente en presas bentónicas y epibentónicas (bivalvos, gasterópodos, ofiuras, crustáceos peracáridos)
(tabla 5). Se comporta como un depredador oportunístico capaz de actuar también como carroñero y
sedimentívoro.
MACPHERSON,
E., 1980. Régime alimentaire de
Galeus melastomus Rafinesque, 1 8 10
Etmopterus spinax (L., 1758) et Scymnorhinus
licha (Bonnaterre, 1788) em Méditerranée
occidentale. Vie Milieu, 30: 139-148.
L. B., 1981. West
MANNING,
R. B. & HOLTHUIS,
African Brachyuran crabs (Crustacea:
Decapoda). Smithsonian Contr. Zool., 306: 1379.
MORI,M., 1982. Osservazioni sull'alimentazione
di Conger conger dei fondi batiali liguri. Boll.
Mus. 1st. Biol. Univ. Genova, 50 suppl.: 391.
- 1986. Contributions to the biology of
REFERENCES
Paromola cuvieri (Crustacea: Decapoda:
Brachyura) in the Ligurian Sea. Oebalia, 13
A B E L L ~P.,, 1989. Feeding habits of Macropipus
N.S.: 49-68.
tuberculatus (Brachyura, Portunidae) off the
MURA,M., 1987. Crostacei Decapodi batiali della
Catalan coast (NW Mediterranean). Misc.
Sardegna meridionale. Rend. Sem. Fac. Sci.
Zool., 13: 45-50.
Univ. Cagliari, 57(2): 189-199.
ABELL~,
P., PERTIERRA,
J. P. & REID,D. G., 1990.
NG, P. K. L. & TAN,L. W. H., 1985. 'Right handSexual size dimorphism, relative growth and
edness' in heterochelous calappoid and
handedness in Liocarcinus depurator
xanthoid crabs. Suggestion for a functional
(Brachyura: Portunidae). Scientia Marina, 54:
advantage. Crustaceana, 49: 98-100.
195-202.
PASTORE,
M., 1981.1 popolamenti dell'infralitoraA.,
ABELL~,
P., VALLADARES,
F. J. & CASTELLÓN,
le di substrato roccioso lungo la costa salenti1988. Analysis of the structure of decapod
na (Golfo di Taranta). 1 Crostacei Decapodi.
crustaceans assemblages off the Catalan coast
Thalassia Salentina, 11: 137-155.
(North-West Mediterranean). Marine Biology,
G., 1981. Biologia di
RELINI,L. & FANCIULLI,
98: 39-49.
Phycis blennioides: distribuzione e alimentaATTRILL,M. J., HARTNOLL,
R. G. & RICE,A. L.,
zione sui fondi da pesca batiali del Mar
1991. Aspects of the biology of the deep-sea
Ligure. Quad. Lab. Tecnol. Pesca Ancona, 3
crab Geryon trispinosus from the Porcupine
( 1 suppl.): 135-144.
Seabight. J. mar. biol. Ass. U.K., 71: 31 1RELINI,L. & MORI,M., 1977. Osservazioni sull'ali328.
mentazione dei Geryon longipes A. Milne
L. M., 1989. The relationship between
CAMMEN,
Edwards 1881 (Crustacea Decapoda Brachyura)
ingestion rate of deposit feeders and sediment
dei fondi batiali liguri. In: Atti IX Congr. Soc.
nutritional value. In: Lecture Notes on Coastal
Ital. Biol. Mar. Ischia: 375-387 (F. Cinelii, E.
and Estuarine Studies: Ecology of Marine
Fresi & L. Mazzella, Eds.). La Seppia, Firenze.
Deposit feeders: 201-222 (G. Lopez, G.
SARDÁ,F., 1983. El proceso de la regeneración de
Taghon & J. Levinton, Eds.). Spnnger-Verlag,
quelas en la cigala Nephrops nowegicus (L.).
New York.
Inv. Pesq., 47: 113-123.
CLARK,P. F., 1986. North East Atlantic Crabs.
SIEGEL,
S., 1956. Statistica non parametrica per le
Marine Conservation Society, Ross-on-Wye.
scienze del comportamento. Edizione OIS,
HAMILTON,
P. V., NASHIMOTO,
R. T. & HALUSKY,
Firenze.
J. G., 1976. Cheliped laterality in Callinectes
J. L., 1985. Reversal of handedness,
SIMONSON,
sapidus (Crustacea: Portunidae). Biol. Bull.,
growth, and claw stridulation patterns in the
150: 393-401.
stone crab Menippe mercenaria (Say)
HARTNOLL,
R. G., 1982. Growth. In: The biology
(Crustacea: Xanthidae). J. Crust. Biol., 5: 281of Crustacea. 2. Embriology, Morphology and
293.
Genetics: 111-196 (D. E. Bliss, Ed.).
VACCHI,M. & RELINI,L., 1979. Alimentazione di
Academic Press, New York.
Chimaera monstruosa L. sui fondi batiali liguINGLE,R. W., 1981. British crabs. British Museum
n . Atti Soc. Tosc. Sci. Nat. Mem., ser. B, 86
(Natural History) & Oxford University Press,
(suPP~.):388-391.
London.
VANNINI,
M. & GHERARDI,
F., 1988. Studies on the
Misc. Zool. 18, 1995
pebble crab, Eriphia smithi MacLeay 1838
(Xanthoidea Menippidae): patterns of relative
growth and population structure. Tropical
Zool., 1: 203-216.
VERMEIJ,
G. J., 1977. Pattems in crab claw size:
the geography of crushing. Syst. Zool., 26:
138-151.
WARNER,
G. F., 1977. The biology of crabs. Elek
Science, London.
L., 1989. Small-scale features of marine
WATLING,
sediments and their importante to the study of
deposit feeding. In: Lecture Notes on Coastal
and Estuarine Studies: Ecology of Marine
Deposit feeders: 269-290 (G. Lopez, G.
Taghon & J. Levinton, Eds.). Springer-Verlag,
New York.
WILLIAMS,
M. J., 1981. Methods for analysis of
natural diet in portunid crabs (Crustacea:
Decapoda: Portunidae). J. Exp. Mar. Biol.
Ecol., 52: 103-113.
R., 1968. Crustáceos
ZARIQUIEY-ÁLVAREZ,
Decápodos Ibéricos. Inv. Pesq., 32: 1-510.