shrimp showed blue coloration of the abdomen 

 and injection site. The abdominal color faded 

 slowly but remained distinct in some for over 

 60 days. The blue to blue -gray branchial 

 staining was retained for the duration of the 

 120 -day experiment. 



Thirty additional shrimp were injected 

 with a 1 -percent solution as above. Initial 

 staining was similar to that detailed in the pre- 

 ceding test. Cannibalism accompanying ecdysis 

 was high, and only 7 individuals remained after 

 52 days. 



Fifteen ahrimp given 5 feedings stained 

 with a similar solution showed a temporary 

 blue coloration of the digestive tract. All evi- 

 dence of staining disappeared within 3 days 

 after the final stained feeding. 



Ten shrimp, divided into 3 lots, were 

 immersed for periods of 7, 5, and 3 minutes 

 in a 1 -percent solution prepared with 25 ml. of 

 distilled water and 275 ml. of sea water. Two 

 of 3 shrimp immersed for 7 minutes were dead 

 at completion of the staining period. In the re- 

 mainder, abnormal coloration was confined to 

 a slight bluish tinting of the branchiae and an- 

 terior margins of the antennal scales . Normal 

 coloration was attained within 48 hours. 



Ten shrimp injected with a 1 -percent 

 solution made up with 5 ml. of distilled water 

 and 95 ml . of sea water showed an immediate 

 general pink coloring and definite branchial 

 concentration. The general coloration persisted 

 in several individuals for at least 70 days, and 

 a bright-red branchial staining was very evident 

 in 4 shrimp which survived 234 days. 



Eleven shrimp injected with a 1 -percent 

 solution prepared with 10 ml. of distilled water 

 and 90 ml. of sea water showed similar colora- 

 tion on injection . Abdominal staining faded 

 within 16 days, but the red branchial concentra- 

 tion was fast in the one shrimp remaining after 

 220 days. 



Eleven shrimp were given injections, 

 averaging . 03 cc, of a 1 -percent solution pre- 

 pared as above but warmed to facilitate dissolv- 

 ing of the dry stain. Abnormal coloration was 

 essentially similar to that in the previous ex- 

 periment. On the thirty -ninth day two shrimp 

 showed loss of equilibrium and rested on their 

 side rather than in the normal position. When 

 stimulated, both showed normal swimming 

 ability but lost balance shortly after coming to 

 rest. Both were cannibalized within 7 days. 

 Five shrimp surviving 46 days retained abnormal 

 branchial color as previously described. 



Trypan Red (Harleco) 



Ten shrimp were injected with a 1 -per- 

 cent solution made up with 5 ml. of glycerine 

 and 95 ml. of sea water. A slow diffusion re- 

 sulted in a general pink color with bright -red 

 concentrations in the branchiae and injection 

 area . Rapid abdominal fading followed, but 

 distinctive branchial coloration remained fast 

 in 4 shrimp surviving 245 days . 



Two lots of 10 and 15 individuals were 

 injected with a 1 -percent solution prepared 

 with 10 ml. of distilled water and 90 ml. of sea 

 water. A mortality of 18 shrimp within 72 

 hours was attributed to excessive injection vol- 

 umes. Staining was essentially the same as in 

 the preceding test, but the general coloration 

 was persistent, together with the branchial con- 

 centration, in the 3 shrimp remaining through 

 124 days. 



Thirty-three shrimp given injections, 

 averaging 0.05 cc, of a I -percent solution pre- 

 pared with sea water showed pink abdominal and 

 red branchial colorations. A high mortality re- 

 sulted in the loss of 25 individuals within 10 days. 

 Abdominal fading was slow but the branchial 

 color was fast in the remainder and was evident 

 in the one shrimp surviving 175 days. 



Ten shrimp were given four feedings, 

 stained with a 1 -percent solution made up with 

 10 ml. of distilled water and 90 ml. of sea water, 

 at 4-, 2-, and 4-day intervals. Red branchial 

 concentration was apparent after the third feed- 

 ing, and several showed diffuse red staining of 

 the entire cephalothorax. Branchial color was 

 retained through at least three shedding periods 

 and was very evident in the one individual sur- 

 viving 215 days after the final stained feeding. 



Fifteen shrimp given three feedings 

 stained with a 2 -percent solution prepared with 



15 



