Feeding ecology of the sand shrimp Crangon hakodatei Rathbun, 1902 (Decapoda: Crangonidae) in the East Sea of Korea

Figures & data

Figure 1.  Sampling areas in this study, areas 1, 2, and 3 are those of rectangle, circle, and triangle, respectively.

Figure 2.  Proportion of stomach fullness scale of Crangon hakodatei by size for (A) autumn, (B) winter, and (C) spring.

Figure 3.  Relative importance of major stomach contents of Crangon hakodatei in overall diets for all combined samples irrespective of areas (Alg, algae; Amp, amphipods; Cum, cumaceans; Dec, decapods; Iso, isopods; Mol, molluscs; Mys, mysids; Pis, pisces; Pol, polychaets; Otc, other crustaceans; Oth, other species; Nem, nematodes).

Table 1. Diet composition of Crangon hakodatei in the three seasonal groups and two size groups (%F, frequency of occurrence; %N, percentage abundance).

Area	Autumn				Winter				Spring
Size class	Small		Large		Small		Large		Small		Large
Number examined	47		52		42		42		40		41
Prey item	%F	%N	%F	%N	%F	%N	%F	%N	%F	%N	%F	%N
POLYCHAETA	2.13	1.00	9.62	5.38	9.52	6.25	2.38	1.23	22.50	12.00	7.32	1.70
CRUSTACEA
Mysidacea	23.40	18.00	21.15	17.20	26.19	16.30	26.19	18.50	22.50	20.00	12.20	13.00
Amphipoda	38.30	22.00	32.69	21.50	38.10	27.50	33.33	23.50	42.50	24.00	31.71	16.00
Isopoda	6.38	5.00	9.62	5.38	7.14	3.75	2.38	1.23	0.00	0.00	7.32	1.00
Cumacea	8.51	5.00	1.92	1.08	7.14	5.00	4.76	4.94	7.50	4.00	19.51	3.20
Decapoda	2.13	1.00	5.77	3.23	7.14	3.75	9.52	7.41	15.00	8.00	4.88	4.00
Copepoda	4.26	3.00	9.62	7.53	2.38	1.25	9.52	6.17	2.50	1.80	2.44	5.00
Unidentified pieces	14.89	8.00	3.85	3.23	9.52	6.25	7.14	3.70	7.50	4.00	4.88	2.10
Other crustacean	4.26	3.00	9.62	6.45	7.14	3.75	7.14	3.70	7.50	4.00	12.20	3.00
MOLLUSCA
Bivalvia	2.13	1.00	5.77	4.30	7.14	3.75	4.76	2.47	7.50	3.20	7.32	6.00
Gastropoda	6.38	4.00	1.92	1.08	4.76	2.50	7.14	4.94	7.50	4.00	7.32	6.00
FISH
Pisces	6.38	4.00	1.92	1.08	7.14	3.75	4.76	2.47	0.00	0.00	0.00	0.00
Backbone	4.26	3.00	1.92	1.08	0.00	0.00	7.14	4.94	7.50	4.00	4.88	4.60
Eggs	6.38	2.00	5.77	3.23	4.76	2.50	0.00	0.00	7.50	4.00	2.44	0.40
ALGAE	6.38	4.00	3.85	2.15	0.00	0.00	0.00	0.00	2.50	2.80	0.00	0.00
OTHER	19.15	3.00	19.23	14.00	14.29	7.50	19.05	12.30	15.00	8.00	7.32	5.20
NEMATODA	0.00	13.00	3.85	2.15	11.90	6.25	4.76	2.47	0.00	0.00	7.32	0.00

Figure 4.  Relative importance of major stomach content items for areas 1 and 2 samples pooled by size classes: small (<10 mm CL) and large size (>10 mm CL) (Alg, algae; Amp, amphipods; Cum, cumaceans; Dec, decapods; Iso, isopods; Mol, molluscs; Mys, mysids; Pis, pisces; Pol, polychaets; Otc, other crustaceans; Oth, other species; Nem, nematodes).

Figure 5.  Relative importance of major stomach contents for Crangon hakodatei samples pooled by seasons (A) autumn, (B) winter and (C) spring (Alg, algae; Amp, amphipods; Cum, cumaceans; Dec, decapods; Iso, isopods; Mol, molluscs; Mys, mysids; Pis, pisces; Pol, polychaets; Otc, other crustaceans; Oth, other species; Nem, nematodes).

Figure 6.  Trophic diversity (A) and equality (B) of prey items found in small and large size classes of Crangon hakodatei at each season.