Grutter,
A.S., Deveny, M.R., Whittington, I.D. and R.J.G. Lester. 2002.
The effect of the cleaner fish Labroides dimidiatus on
the capsalid monogean Benedenia lolo parasite of the
labrid fish Hemigymnus melapterus. Journal of Fish
Biology 61:1098-1108.
Cleaner
wrasses have long been recognized as predators on various
parasitic crustaceans commonly found on fish. This study shows
that the common south Pacific cleaner wrasse, Labroides
dimidiatus, can also feed on and control, the monogean (trematode)
parasite Benedenia
lolo, on the wrasse Hemigymnus
melapterus. Monogeans often become problematic in
aquaculture and aquaria situations once they are introduced due
to poor quarantine procedures. They can often show explosive
growth in numbers and can be very difficult to eradicate once
introduced. Chemicals and freshwater baths are often used to
control their numbers and prevent their introduction into
systems but these can be expensive and/or time consuming.
This
is a photo, taken by Julian Sprung, of a yellow puffer (Anthron sp.) with a cleaner wrasse (Labroides dimidiatus) entering its gill for cleaning purposes. For
those of you who recall this photo was used as the cover
photo for the original Aquarium
Frontiers, Fall 1994.
This
study examined how effective the cleaner wrasse was in removing
monogeans and what effect they would have on their abundance and
size-frequency distribution under the controlled conditions of an
aquarium. In the test aquaria it was found that small fish (<11.5 cm)
had 100x the number of monogeans of wild small fish while large fish
(>11.5 cm) had 15x the number. Small fish had higher densities of
monogeans than larger fish and had greater numbers of small monogeans
(<1 mm) indicating that small fish appeared to be more susceptible to
infection by the motile infectious stage of monogeans. However, large
fish had more large monogeans (> 3mm). Fish can exhibit immunity to
parasites and this immunity can be acquired.It was thought that the increased susceptibility to monogeans in
smaller fish might be linked to a lower resistance to disease as has
been shown in other fish parasites and fish species and that as they
grow larger they acquire an increased immunity to infection.
In
the presence of cleaner wrasses, small fish had significantly fewer
monogeans than fish not exposed to cleaner wrasses. The abundance on
large fish was not affected. Within the two fish size-classes, cleaner
wrasses did affect the size-frequency distribution of monogeans. Fish
had fewer large monogeans and more small monogeans than those fish not
exposed to cleaner wrasses. This effect was more pronounced on large
fish than on small fish.
This
study indicates that cleaner wrasses can help to control benedeniine
monogean populations in closed systems; however, there is a difference
in how they can affect the population depending on the size of the fish
involved. By selectively removing large monogeans, cleaner wrasses can
help to slow the spread of infection and perhaps, over time, even
eliminate them from systems. However, for hobbyists that have relatively
small systems with low fish densities, and who should be acquiring fish
that have already been adequately quarantined, the role of cleaner
wrasses in such systems in questionable. Wholesalers and other importers
on the other hand, may benefit from keeping a small population of
cleaner wrasses in large holding systems where large fish are regularly
held. This does not, however, preclude the need for pretreating fish
upon arrival from areas known to have high incidences of monogean
infections on fish e.g. Marshall Islands, Christmas Island with
freshwater baths or medication.
For
public aquariums or other facilities that house large populations of
both large and small fish, cleaner wrasses can be useful tools to help
control the spread of benedeniine monogeans or while chemical means are
used to totally eradicate them.
Unless you
are 110% confident that the fish you purchase are free
of disease, then hobbyists should always quarantine
any new arrivals in a separate system for at least
three weeks to ensure they are not carrying any
disease and are eating and behaving normally.
Nordemar,I.,
Nystrom, M. and R. Dizon. 2003. Effects of elevated
seawater temperature and nitrate enrichment on the
branching coral Porites cylindrica in the absence of
particulate food. Marine Biology (in press). (Abstract:
http://link.springer.de/link/service/journals/00227/contents/02/00989/)
These two
studies both underline the stresses placed on corals
that are exposed to not only elevated temperatures but
also elevated nitrate and ammonium levels. The levels
of ammonium and nitrate used in these studies are
lower than found in most hobbyist systems and
underscore that our systems are not always close
approximations to nature. This is something that I
have long argued when others have advocated raising
temperatures or making other changes to our systems
while ignoring other factors that can act
synergistically to create problems.
Proud
sponsor of this column
Anemones
Baeza,
J.A. and W. Stotz. 2003. Host-use and selection of differently colored
sea anemones by the symbiotic crab Allopetrolisthes spinifrons. Journal
of Experimental Marine Biology and Ecology 284(1-2): 25-40.
Aquaculture
McMillian,
J.D., Wheaton, F.W., Hechheimer, J.N. and J. Scares. 2003. Pumping
effect on particle sizes in a recirculating aquaculture system. Aquacultural
Engineering 27(1): 53-60.
Rombaut,
G., Grommen, R., Zizhong, Q., Vanhoof, V., Suantika, G., Dhert, P.,
Sorgeloos, P. and W. Verstraate. 2003. Improved performance of an
intensive rotifer culture system by using a nitrifying inoculum (ABIL). Aquaculture
Research 34(2): 149-164.
Cephalopods
Nabhitabhata,
J. 2003. Double eggs of pharaoh cuttlefish, Sepia pharaonis
Ehrenberg, 1831. Veliger 46(1): 97-98.
Norman,
M.D., Paul, D., Finn, J. and T. Tregenza. 2002. First encounter with a
live male blanket octopus: the world’s most sexually size-dimorphic
large animal. New Zealand Journal of Marine and Freshwater Research
36(4): 733-736.
Corals
Anthony,
K.R.N. and O. Hoegh-Guldberg. 2003. Kinetics of photoacclimation in
corals. Oecologia 134(1):23-31.
Duh,
C.Y., Chien, S.C., Song, P.Y., Wang, S.K., ElGamal, A.A.H. and C.F. Dai.
2002. New cadinene sesquiterpenoids from the Formosan soft coral Xenia
puerto-galerae. Journal of Natural Products 65 (12): 1853-1856.
Duh,
C.Y., ElGamal, A.A.H., Chiang, C.Y., Chu, C.U., Wang, S.K and C.F. Dai.
2002. Cytotoxic Xenia diterpenoids from the Formosan soft coral Xenia
umbellata. Journal of Natural Products 65 (12): 1882-1885.
Savage,
A.M., Goodson, M.S., Visram, S., Trapido-Rosenthal, H., Wredenmann, J.
and A.E. Douglas. 2002. Molecular diversity of the symbiotic algae at
the latitudinal margins of their distribution: dinoflagellates of the
genus Symbiodinium in corals and sea anemones. Marine Ecology
Progressive Series 244:17-26.
Saxby,
T., Dennison, W.C. and O. Hoegh-Guldberg. 2003. Photosynthetic responses
of the coral Montipora digitata to cold temperature stress. Marine
Ecology Progressive Series 248: 85-97.
Sheu,
J.H., Ahmed, A.F., Shiue, R.T., Dai, C.F. and Y.H. Kuo. 2002.
Scabrolides A-D, four new norditerpenoids isolated from the soft coral Sinularia
scabra. Journal of Natural Products 65 (12): 1904-1908.
Vermeij,
M.J.A., Sampayo, E., Bröker, K. and R.P.M. Bak. 2003.Variation in planulae release of closely related coral species. Marine
Ecology Progressive Series 247: 75-84.
Yacobovitch,
T., Weis, V.M. and Y. Benayah. 2003. Development and survivorship
of zooxanthellate and azooxanthellate primary polyps of the soft coral
Heteroxenia fuscescens: laboratory and field comparisons. Marine
Biology (In press). (Abstract: http://link.springer.de/link/service/journals/00227/contents/03/01035/).
Ecology
Knott,
M. 2003. The net is closing on coral reef bombers. New Scientist
177(2377): 6-7.
Nagelkerken
I. and G. van der Velde. 2002. Do non-estuarine mangroves harbour higher
densities of juvenile fish than adjacent shallow-water and coral reef
habitats in Curaçao (Netherlands Antilles)? Marine Ecology
Progressive Series 245: 191-204.
Nagelkerken,
I., Roberts, C.M., vanderVelde, O., Dorenbosch, M., vanRiel, M.C.,
delaMorinere, E.C. and P.H. Nienhuis. 2002. How important are mangroves
and seagrass beds for coral reef fish? The nursery hypothesis tested on
an island scale. Marine Ecology Progressive Series 244: 299-306.
Sale,
P. and R. Bshary. 2003. Coral reef fishes: Diversity and dynamics in a
complex ecosystem. Nature 412(6921): 317-319.
Finley
RJ, Forrester GE. 2003. Impact of ectoparasites on the demography of a
small reef fish. Marine Ecology Progressive Series248:305-309.
Greenfield,
D.W. and K. Matsuura. 2002. Scorpaenades quadrispinosus: a new
indo-Pacific scorpionfish (Teleostei: Scorpaenidae). Copeia 4:
973-978.
Mitchel,
J.S. 2003. Social correlates of reproductive success in fake clown
anemonefish: subordinate group members do not pay-to-stay. Environmental
Ecology Research 5(1):89-104.
Seagrass
Agawin,
N.S.R. and G.M. Duarte. 2002. Evidence of direct particle trapping by a
tropical seagrass meadow. Estuaries 25(6A): 1205-1209.
Durako,
M.J., Kunzelman, J.I., Kenworthy, W.J. and K. K. Hammerstrom.
2003. Depth-related variability in the photobiology of two populations
of Halophila johnsonii and Halophila decipiens. Marine
Biology (In press). (Abstract:
http://link.springer.de/link/service/journals/00227/contents/03/01038/).
Thomas,
F.I.M. and C.D. Cornelisen.2003.
Ammonium uptake by seagrass communities: effects of oscillatory versus
unidirectional flow.Marine
Ecology Progressive Series247: 51–57.
Sponges
The
second 2003 issue of Journal of Biotechnology (vol. 100 issue 2) is a
special installment entitled, Biotechnological Aspects of Marine
Sponges. It contains several papers dealing with the culture of
marine sponges and would be a useful issue for those interested in
culturing and growing sponges in aquaria.
Guzmán,
H.M., Guevara, C.A. and I.C. Hernández. 2003. Reproductive cycle of two
commercial species of sea cucumber (Echinodermata: Holothuroidea) from
Caribbean Panama.Marine Biology
(2003) 142: 271-279.
Ramofafia,
C., Byrne, M. and C. S. Battaglene. 2003. Reproduction of the commercial
sea cucumber Holothuria scabra (Echinodermata: Holothuroidea) in
the Solomon Islands. Marine
Biology (2003) 142: 281-288.
Steindler,
L., Beu, S. and M. Ilan. 2002. Photosymbiosis in intertidal and subtidal
tropical sponges. Symbiosis 33(3):263-?.
