Camp.Biochem. Physioi.. 1977, Vol. 56A,pp. 19 IO 22. Pergamon Press. Printed tn Great Britain
THE STIMULATION OF FILTER FEEDING IN THE PORCELAIN CRAB PETROLISTHES CINCTIPES RANDALL BY AMINO ACIDS AND SUGARS
H. BERNARD HARTMAN AND MAKIKO S. HARTMAN Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, U.S.A. and Oregon Institute of Marine Biology, Charleston, OR 97420, U.S.A.
(Received 29 March 1976)
Abstract-l. The porcelain crab Petrolisthes cinctipes Randall is stimulated to filter feed by amino acids and sugars. 2. The most stimulatory amino acids are L-tyrosine > glycine > L-proline > L- and D-glumatic acid > y-amino-n-butyric acid. 3. The most stimulatory sugars are trehalose and glucose. 4. Glutathione. peptides of glycine, and peptides of glycine and tyrosine are weakly stimulatory.
stock of about 200 animals, 5 randomly selected P. cinc- tipeswere placed in each of 4 large finger bowls. The bowls There is a growing literature describing the electro- contained 5OOml of filtered fresh sea water at 1@14”C physiology of chemoreception and the anatomy of with a pH ranging from 7.4-8.0. Small stones were intro- chemoreceptive structures in Crustacea. Hodgson duced into the bowls to provide a natural substrate for (1958) recorded electrical activity from neurons of the animals to grip; the room was darkened and the ani- setae on the chelae and walking legs of crayfish using mals allowed to acclimate for l&l5 min. amino acids as stimuli. Case & Gwilliam (1961) and A typical experimental run included a blank control, a glycine control, and 2 different compounds for assay. The Case (1964) extended these findings by showing that blank control was 5 ml of distilled water gradually pipetted chemoreceptors associated with dactyls of the walking into one finger bowl. The glycine control was 5 ml of legs of Carcinus mnaenas, Cancer antennarius, and 10-l M glycine in distilled water pipetted into another Cancer productus respond to specific amino acids. finger bowl. The latter served as a test of the feeding readi- More recently, Shelton & Laverack (1968) have speci- ness of the crabs. Preliminary investigation indicated that fied certain setae on the dactyls of C. maenas and this amino acid was particularly effective in promoting Homarus vulgaris as being chemoreceptive. filter feeding, and if 60% of this control group did not Little research has been reported on compounds initiate feeding, the results of the entire run were dis- promoting feeding behavior in Crustacea. Case et al. counted. Into the third bowl was pipetted 5 ml of a 10-l M solution of a compound to be assayed; this was repeated (1960) comment that amino acids evoking an electro- with the fourth compound in the remaining bowl. The ani- physiological response from dactyl chemoreceptors mals were observed for 2 min, and those actively filter feed- also arouse feeding movements when applied to the ing were counted. chelae and mouthparts of intact C. muenas. However, All solutions were made up immediately before use in we have no knowledge of detailed experiments with distilled water to concns ranging from 10-l to 10m4M. Crustacea where feeding behavior is used as the cri- For those compounds which are particularly acidic or terion for chemoreception of specific compounds. basic, the sea water in the assay bowls was buffered using We observed that while the porcelain crab Petro- Tris to the pH of the blank and glycine control bowls. listhes cinctipes Randall will commence filter feeding Checks using fluorescein mixed with the glycine control showed that the pipetted material was initially rapidly when newly hatched brine shrimp hernia salina are distributed about the finger bowl aided chiefly by the cur- introduced into their aquarium, they are also stimu- rent created by baling movements of the scaphognathites, lated to filter feed by the dialyzate of the hatch solu- and the beating of the flagella of the exopodites of the tion. As no macroscopic particles are present in the maxillipeds. Feeding was initiated best when there was a latter solution, the feeding must be stimulated by the gradient or front approaching the animals. Preliminary ex- chemoreception of small compounds. Since P. cinc- periments indicated that Petrolisthes would not feed if tipes is relatively abundant and reliably responds with placed in finger bowls containing homogeneous solutions stereotyped filter feeding, we set out to determine the of glycine. specific compounds evoking the behavior. RESULTS MATERIALS AND METHODS The filter feeding behavior of Porcellam longicornis The porcelain crab Petrolisthes cinctipes Randall col- has lected in the rocky high and middle tide zones of North been carefully described by Nicol (1932) and that Cove at Cape Arago, OR was used in this investigation. of Petrolisthes cinctipes is very similar. The porcelain The animals were starved for at least 2 days prior to exper- crab firmly grips the substrate with the sharp dactyls iments by filtering the sea water entering the aquarium of the 3 pairs of walking legs. The beating of the through a fiberglass trap. From a frequently replenished flagella of the exopodites on the maxillipeds aided 19 20 H. BERNARDHARTMAN AND MAKIKO S. HARTMAN
by the exhalent current of water from the branchial Table 2. Feeding activity evoked by dicarboxylic, aromatic, chamber draws particle laden water across the front heterocyclic amino acids, and related compounds of the carapace. Here the chemosensory antennules sample the water current for food. Upon chemical No. of stimulation, the beating of the flagella stops and animals Per- Concn feeding/ another water current created by the alternating ten tage Compound (M)* tested feeding movements of the third maxillipeds takes over. The 2nd through 5th segments of the third maxillipeds control (distilled bear rows of long pinnate sctae. When the limb is water) - 361285 13 extended, the setae form a spoon-shaped scoop control (glycine) 10-l 2061285 72 extending over a large area. The limbs are cast L-aspartic acid 10-l l/15 7 sideways alternately and flexed back towards the mid- Dr.-aspartic 10-l 2115 I3 line trapping suspended particles in the setae. A ter- L-glutamic acid lo- ’ 30145 67 minal brush of setae on the basal segment of the L-glutamic acid IO-’ IO/I5 67 L-glutamic acid IOm3 4115 27 second maxilliped on the same side, scrapes the par- o-glutamic acid lo- 1 II/I5 73 ticles from the setae of the flexed maxilliped and L-tyrosine 10-l 15/15 100 passes them to the mouth (Nicol, 1932). The behavior L-tyrosine 1O-2 27145 60 is the same and continues for some minutes in Petro- L-tyrosine 10-3 28145 62 listhes even though no particles are trapped in the L-tyrosine 10-4 2130 7 setae of the third maxillipeds. D-tyrosine IO-’ 3115 20 The effectiveness of aliphatic amino acids in pro- D-tyrosine 10-A o/15 0 moting filter feeding was assayed in the first series DL-phenylalanine 10-l 5115 33 L-P-3,Cdihydroxy- of experiments (Table 1). Glycine was by far the stron- phenylalanine lo- ’ 2/15 13 3-hydroxytyramine 10-l o/15 0 Table 1. Feeding activity evoked by aliphatic amino acids L-tryptophan IO_’ 18130 60 and related compounds L-tryptophan 1o-2 5115 33 L-tryptophan 1o-3 3115 20 No. of L-proline 10-l 25130 83 animals Per- L-proline lo-2 IO/15 67 Concn feeding/ centage L-proline 1o-3 6115 40 L-proline Compound (M)* tested feeding 1O-4 l/15 7 hydroxy-L-proline lo- ’ 3115 20 control (distilled L-histidine 10-l 6115 40 water) - 411360 11 control (glycine) 10-l 2731360 16 *See footnote of Table 1. glycine 1O-2 11/15 73 glycine 10-j 20,‘30 67 glycine 10-4 5/30 17 gest stimulant in this group. Concentrations of N-methyl glycine < lo- ’ M evoked a feeding response in 76% of the (sarcosine) lo- ’ O/I5 0 crabs while concns of Table 3. Feeding .activity evoked by peptides Table 5. Feeding activity evoked by monosaccharides, di- saccharides, amino sugars No. of animals Per- No. of Concn feeding/ centage animals Per- Compound (M)* tested feeding Concn feeding/ centage Compound (W* tested feeding control (distilled water) S/l05 8 control (distilled control (glycine) 10-r El/105 II water) 13/180 I glycylglycine 10-l 9/30 30 control (glycine) lo- 1 128/180 72 glycylglycylglycine 10-l o/15 0 rl-D-glucose 10-r 23145 51 glutathione lo- ’ 2130 I ~-D-glucose 10-l 21145 41 glutathione 10-I 2115 13 D-galactose IO_ ’ 3115 20 L-tyrosylglycine 10-l 4110 40 D-mannose lo- 1 2115 13 glycyl-L-tyrosine lo- ’ 2115 13 /3-D-fructose 10-r 3115 20 cc-r_-fucose lo- ’ 2115 13 * See footnote of Table 1. D-xylose 10-l 16145 36 D-f yXOSe lo- ’ 2115 13 effective stimulus. The structurally related compounds sucrose lo- ’ 4115 27 phenylalanine and ~-p-3,4 dehydroxyphenylalanine maltose 10-r 9145 20 (DOPA) were not effective stimuli, and 3-hydroxytyr- trehalose lo- I I E/30 60 amine suppressed feeding. L-tryptophan was modera- trehalose lo- I 3115 20 tely stimulatory at < lo- ’ M, but far less so at lower trehalose IO-2 2115 20 concns. glucosamine 10-3 5115 33 N-acetyl-D- The heterocyclic amino acid L-proline was a par- glucosamine lo- I 1l/30 31 ticularly stimulatory compound (Table 2). Eighty- three per cent of the crabs responded to a concn of * See footnote of Table 1.