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Photoelectric measurement of lobster (homarus americanus) response to feed attractants
Aquacultural Engineering 1 (1982) 5-9
P H O T O E L E C T R I C M E A S U R E M E N T OF LOBSTER ( H O M A R U S A M E R I C A N U S ) RESPONSE TO FEED A T T R A C T A N T S
ROBERT C. BAYER,'~ JOHN RILEY,$ JAMES H. RITTENBURG,'~ DALE F. LEAVITT'~ and MARGIE LEE GALLAGHER-~
Departments of tAnimal and Veterinary Sciences, and gAgricultural Engineering, University of Maine, Orono, Maine 04469, USA
ABSTRA CT
The apparatus described was designed to measure the speed and direction of lobster response to feed attractants with minimal observer influence on the test animal. Lobster activity was monitored in an 8 4 x l O x 1 0 i n ( 2 1 3 x 2 5 x 2 5 c m ) plexiglas tank based on interruption o f photoelectric cells. Impulses from the photocells trigger the pens o f a 6-channel event recorder. During its operation the apparatus is covered with an opaque plastic sheet. Lobster behavior was such that the animals always settled in one o f the chamber ends and the test material could be injected at the far end. The lobsters responded to a variety o f test materials.
INTRODUCTION
Several methods have been used previously to study the reaction of lobsters to constituents in their environment. Mackie and Shelton (1972) designed a chamber with a shelter habitat and one-way mirrors for direct observation of lobsters' behavior when exposed to potential attractants, without the observer influencing this behavior. McLeese (1972) blindfolded lobsters, tagged them with fluorescent paint, and recorded movement using ultraviolet light. A photograph, taken with a three-minute time exposure, traced the path of the lobster in its response to attractants. Allen et al. (1975) pumped water from a pre-soaked bait in a small tank into a larger tank containing a mature Dungeness crab (Cancer magister). Direct behavioral observations were made of the crab's response. The apparatus described in this paper was designed to measure and record the directional response of lobsters to feed attractants with minimal observer influence on the test animal. 5 Aquacultural Engineering 0144-8609/82/0001-0005/1;02.75 O Applied Science Publishers Ltd, England, 1982 Printed in Great Britain
6
BAYER et aL
MATERIALS AND METHODS The activity monitoring system is based on the interruption of light beams by the moving lobsters. A tank 84 × 10 x 10in (213 × 25 × 25 cm) was fabricated from 1in (0-635 cm) plexiglas, with angle iron reinforcing at the corners, and a rigid supporting base of 3 in (1-905 cm) plywood. Six photoelectric cells were mounted along one side of the tank at equal spacings with six light sources along the opposite side, each being aimed at its corresponding photocell; see Fig. 1.
~OVERFLOW
,N.~LE ..J
"~
f~/4"Plexiglas ~
~
~
~
LI/2"xl/2" Angle
~ ~'5/4"Plywood
I~lO"-~l P HOTOCELL . . . ~ K . . / L
IGHT SOURCE
SectionA-A Fig, 1.
Experimental activity monitoring apparatus.
The output signal from each photocell operates the coil of a relay, the output of which is connected to one channel of a 6-channel event recorder. With the photocell receiving light from the source, the relay contacts are held open and no signal reaches the recorder. Interruption of the light beam causes the relay to close, actuating the event recorder pen for that particular channel. When the light beam is restored, the recorder pen returns to a central 'off' position. Figure 2 shows a schematic of the instrumentation circuitry. The light sources and photocells were designed to operate up to 180 cm apart. At the 60 cm separation in this application the amount of light received is far greater than that needed to generate a signal strong enough to operate the relays. It was felt that the levels of lighting in the tank should be kept as low as possible, primarily to reduce distraction to the lobster, but also because the lobster is by nature nocturnal and would be more likely to respond naturally in a relatively dark environment. The light sources were therefore partially covered so that only a thin vertical beam was projected. The tank was filled with water dyed to simulate the poorest visibility, due to suspended silt, likely to be encountered, and the size of the light beam was gradually reduced until further reduction actuated the relay and event recorder. These tests were conducted with the tank covered by black polyethylene film so that the effects of ambient light on the photocells would be reduced as much as possible.
LOBSTER RESPONSE TO FEED ATTRACTANTS
,,5 VAC
~
~
'~
'~
'~
7
'[~ LIGHT SOURCES (SIGMA SERIES 8)
+12VDC -12 VDC 115VAC ( RECORDERDRIVE) Fig. 2.
~
( DAYTONSPOT)
EVENT RECORDER ( ESTERLINE-ANGUS) ( 8- CHANNEL)
Schematic of instrumentation circuitry of activity monitoring apparatus.
The tank was provided with water inlet and overflow connections. To perform a feeding response test, the inlet was connected to a supply of sea water, the tank was filled, and then the flow rate was adjusted to give the desired flow through the tank. The tests were conducted using lobsters weighing 400-500 g; they were fasted for 2 - 4 weeks prior to the tests, since Mackie and Shelton (1972) had shown that fasted lobsters were more responsive to attractants. The lobsters were placed in the tank and given 15 min to acclimate as sea water flowed through the tank. After this waiting period, water flow was stopped and the test substance was injected into the water inlet tube. The inlet valve was then opened for approximately 1 s to force the test substance into the tank, this time being determined by earlier dye injection tests aimed at delivering the dye to the point where the inlet pipe joined the tank. As the test lobster moved down the tank in response to the feed its movement was traced on the recorder as a series of events corresponding to each interruption of a light beam. The sequence of events thus allowed determination as to there being a positive or negative response to the feed or attractant, and the spacing of the events allowed a comparison of the rate of the response. Knowing the distance between the photocells and the strip chart paper speed, quantitative values for the speed of response could be obtained if necessary. Figure 3 shows a sample of recorder chart for a positive response in which the lobster moved directly from one end o f the tank to the other end at which the attractant was located. A lobster was used for three or four test substances and then replaced. A lobster h e m o l y m p h injection into the tank after this number of tests produced a negative response, indicating that the animal was fatigued or conditioned in some way; lobster h e m o l y m p h has been shown to be a potent natural attractant. Attractants o f various types were tested. Amino acids were tested as had previously been done by McLeese (1972), Mackie and Shelton (1972), and others, along with
8
BAYER
e t al.
! !
2
~
4
5
e[
Ig--
I Fig. 3.
S a m p l e strip c h a r t r e c o r d i n g s h o w i n g m o v e m e n t o f l o b s t e r s f r o m o n e e n d o f t a n k to another.
TABLE 1 S u m m a r y o f r e s p o n s e o f l o b s t e r s to test a t t r a c t a n t s
Test substance
Day response
Night response
Xanthine Fish f l a v o r a B alanine Taurine G l u t a m i c acid Guanine Lysine Lobster hemolymph Anise a Uric acid Argenine Homocystine Chocolate flavor a Chicken fat flavor a /-leucine Lysine and trimethylamine H e r r i n g m e a l solubles Glycine Liver flavor a Whole egg h e r r i n g oil e m u l s i o n Cheese f l a v o r a Mussel e x t r a c t
+ +
+ -
+ ± + + -
+_ + + + + + + + + + +
-
+ +
+ I n d i c a t e s positive r e s p o n s e ; - i n d i c a t e s n e g a t i v e r e s p o n s e ; a b l a n k i n d i c a t e s n o t tried, a K e m i n I n d u s t r i e s , Des Moines, I o w a , U S A .
LOBSTER RESPONSE TO FEED ATTRACTANTS
9
some amino acid metabolites. Synthetic food flavors, animal feed flavor additives, sea water soluble extracts of feed ingredients and fish oil emulsions were also tested.
RESULTS AND DISCUSSION Since observations of lobsters indicated that they were more active at night, both day and night trials were conducted. Table 1 summarizes the results of the trials. It can be seen that lobsters demonstrated different responses to the same substance depending on whether the test was performed during the day or at night. The apparatus itself proved to be simple to use and relatively trouble-free. Although most of the testing was done inside a laboratory, the apparatus was designed to be portable. It could be transported by station wagon to a lobster pound or other remote locations, and a small gasoline generator could be used to power a circulating pump, the light sources and the event recorder.
REFERENCES Allen, W. V., Frederick, E. C. & Wong, R. (1975). Experiments on the development of an artificial bait for Dungeness crab, Cancer magister. Sea Grant Bulletin, HSU-SG-7. McLeese, D. W. (1972). Orientation of lobsters (Homarus americanus) to odor. J. Fish. Res. Bd. Can., 30,839-40. Mackie, A. M. & Shelton, R. G. J. (1972). A whole-animal bioassay for the determination of food attractants of the lobster, Homarus gammarus. "Mar. Biol., 14, 217-21.
P H O T O E L E C T R I C M E A S U R E M E N T OF LOBSTER ( H O M A R U S A M E R I C A N U S ) RESPONSE TO FEED A T T R A C T A N T S
ROBERT C. BAYER,'~ JOHN RILEY,$ JAMES H. RITTENBURG,'~ DALE F. LEAVITT'~ and MARGIE LEE GALLAGHER-~
Departments of tAnimal and Veterinary Sciences, and gAgricultural Engineering, University of Maine, Orono, Maine 04469, USA
ABSTRA CT
The apparatus described was designed to measure the speed and direction of lobster response to feed attractants with minimal observer influence on the test animal. Lobster activity was monitored in an 8 4 x l O x 1 0 i n ( 2 1 3 x 2 5 x 2 5 c m ) plexiglas tank based on interruption o f photoelectric cells. Impulses from the photocells trigger the pens o f a 6-channel event recorder. During its operation the apparatus is covered with an opaque plastic sheet. Lobster behavior was such that the animals always settled in one o f the chamber ends and the test material could be injected at the far end. The lobsters responded to a variety o f test materials.
INTRODUCTION
Several methods have been used previously to study the reaction of lobsters to constituents in their environment. Mackie and Shelton (1972) designed a chamber with a shelter habitat and one-way mirrors for direct observation of lobsters' behavior when exposed to potential attractants, without the observer influencing this behavior. McLeese (1972) blindfolded lobsters, tagged them with fluorescent paint, and recorded movement using ultraviolet light. A photograph, taken with a three-minute time exposure, traced the path of the lobster in its response to attractants. Allen et al. (1975) pumped water from a pre-soaked bait in a small tank into a larger tank containing a mature Dungeness crab (Cancer magister). Direct behavioral observations were made of the crab's response. The apparatus described in this paper was designed to measure and record the directional response of lobsters to feed attractants with minimal observer influence on the test animal. 5 Aquacultural Engineering 0144-8609/82/0001-0005/1;02.75 O Applied Science Publishers Ltd, England, 1982 Printed in Great Britain
6
BAYER et aL
MATERIALS AND METHODS The activity monitoring system is based on the interruption of light beams by the moving lobsters. A tank 84 × 10 x 10in (213 × 25 × 25 cm) was fabricated from 1in (0-635 cm) plexiglas, with angle iron reinforcing at the corners, and a rigid supporting base of 3 in (1-905 cm) plywood. Six photoelectric cells were mounted along one side of the tank at equal spacings with six light sources along the opposite side, each being aimed at its corresponding photocell; see Fig. 1.
~OVERFLOW
,N.~LE ..J
"~
f~/4"Plexiglas ~
~
~
~
LI/2"xl/2" Angle
~ ~'5/4"Plywood
I~lO"-~l P HOTOCELL . . . ~ K . . / L
IGHT SOURCE
SectionA-A Fig, 1.
Experimental activity monitoring apparatus.
The output signal from each photocell operates the coil of a relay, the output of which is connected to one channel of a 6-channel event recorder. With the photocell receiving light from the source, the relay contacts are held open and no signal reaches the recorder. Interruption of the light beam causes the relay to close, actuating the event recorder pen for that particular channel. When the light beam is restored, the recorder pen returns to a central 'off' position. Figure 2 shows a schematic of the instrumentation circuitry. The light sources and photocells were designed to operate up to 180 cm apart. At the 60 cm separation in this application the amount of light received is far greater than that needed to generate a signal strong enough to operate the relays. It was felt that the levels of lighting in the tank should be kept as low as possible, primarily to reduce distraction to the lobster, but also because the lobster is by nature nocturnal and would be more likely to respond naturally in a relatively dark environment. The light sources were therefore partially covered so that only a thin vertical beam was projected. The tank was filled with water dyed to simulate the poorest visibility, due to suspended silt, likely to be encountered, and the size of the light beam was gradually reduced until further reduction actuated the relay and event recorder. These tests were conducted with the tank covered by black polyethylene film so that the effects of ambient light on the photocells would be reduced as much as possible.
LOBSTER RESPONSE TO FEED ATTRACTANTS
,,5 VAC
~
~
'~
'~
'~
7
'[~ LIGHT SOURCES (SIGMA SERIES 8)
+12VDC -12 VDC 115VAC ( RECORDERDRIVE) Fig. 2.
~
( DAYTONSPOT)
EVENT RECORDER ( ESTERLINE-ANGUS) ( 8- CHANNEL)
Schematic of instrumentation circuitry of activity monitoring apparatus.
The tank was provided with water inlet and overflow connections. To perform a feeding response test, the inlet was connected to a supply of sea water, the tank was filled, and then the flow rate was adjusted to give the desired flow through the tank. The tests were conducted using lobsters weighing 400-500 g; they were fasted for 2 - 4 weeks prior to the tests, since Mackie and Shelton (1972) had shown that fasted lobsters were more responsive to attractants. The lobsters were placed in the tank and given 15 min to acclimate as sea water flowed through the tank. After this waiting period, water flow was stopped and the test substance was injected into the water inlet tube. The inlet valve was then opened for approximately 1 s to force the test substance into the tank, this time being determined by earlier dye injection tests aimed at delivering the dye to the point where the inlet pipe joined the tank. As the test lobster moved down the tank in response to the feed its movement was traced on the recorder as a series of events corresponding to each interruption of a light beam. The sequence of events thus allowed determination as to there being a positive or negative response to the feed or attractant, and the spacing of the events allowed a comparison of the rate of the response. Knowing the distance between the photocells and the strip chart paper speed, quantitative values for the speed of response could be obtained if necessary. Figure 3 shows a sample of recorder chart for a positive response in which the lobster moved directly from one end o f the tank to the other end at which the attractant was located. A lobster was used for three or four test substances and then replaced. A lobster h e m o l y m p h injection into the tank after this number of tests produced a negative response, indicating that the animal was fatigued or conditioned in some way; lobster h e m o l y m p h has been shown to be a potent natural attractant. Attractants o f various types were tested. Amino acids were tested as had previously been done by McLeese (1972), Mackie and Shelton (1972), and others, along with
8
BAYER
e t al.
! !
2
~
4
5
e[
Ig--
I Fig. 3.
S a m p l e strip c h a r t r e c o r d i n g s h o w i n g m o v e m e n t o f l o b s t e r s f r o m o n e e n d o f t a n k to another.
TABLE 1 S u m m a r y o f r e s p o n s e o f l o b s t e r s to test a t t r a c t a n t s
Test substance
Day response
Night response
Xanthine Fish f l a v o r a B alanine Taurine G l u t a m i c acid Guanine Lysine Lobster hemolymph Anise a Uric acid Argenine Homocystine Chocolate flavor a Chicken fat flavor a /-leucine Lysine and trimethylamine H e r r i n g m e a l solubles Glycine Liver flavor a Whole egg h e r r i n g oil e m u l s i o n Cheese f l a v o r a Mussel e x t r a c t
+ +
+ -
+ ± + + -
+_ + + + + + + + + + +
-
+ +
+ I n d i c a t e s positive r e s p o n s e ; - i n d i c a t e s n e g a t i v e r e s p o n s e ; a b l a n k i n d i c a t e s n o t tried, a K e m i n I n d u s t r i e s , Des Moines, I o w a , U S A .
LOBSTER RESPONSE TO FEED ATTRACTANTS
9
some amino acid metabolites. Synthetic food flavors, animal feed flavor additives, sea water soluble extracts of feed ingredients and fish oil emulsions were also tested.
RESULTS AND DISCUSSION Since observations of lobsters indicated that they were more active at night, both day and night trials were conducted. Table 1 summarizes the results of the trials. It can be seen that lobsters demonstrated different responses to the same substance depending on whether the test was performed during the day or at night. The apparatus itself proved to be simple to use and relatively trouble-free. Although most of the testing was done inside a laboratory, the apparatus was designed to be portable. It could be transported by station wagon to a lobster pound or other remote locations, and a small gasoline generator could be used to power a circulating pump, the light sources and the event recorder.
REFERENCES Allen, W. V., Frederick, E. C. & Wong, R. (1975). Experiments on the development of an artificial bait for Dungeness crab, Cancer magister. Sea Grant Bulletin, HSU-SG-7. McLeese, D. W. (1972). Orientation of lobsters (Homarus americanus) to odor. J. Fish. Res. Bd. Can., 30,839-40. Mackie, A. M. & Shelton, R. G. J. (1972). A whole-animal bioassay for the determination of food attractants of the lobster, Homarus gammarus. "Mar. Biol., 14, 217-21.