Appendix II 



Amphipod Analytical Sheet 



A Checklist of Characters to be Examined Before Using Keys 



Before the keys are utilized for the identification of an amphipod, 

 the morphological characteristics of the organism should be deter- 

 mined. This requires a complete dissection, mounting, and examina- 

 tion of parts on microscope slides as discussed in Appendix I. The 

 follo^^dng checklist may be useful as a guide to characters that should 

 be determined. This procedure is very laborious at first but pays 

 dividends in the final result and makes familiar, more rapidly, those 

 characters which ultimately are most important. Principal characters 

 are italicized. 



The checklist is designed to indicate the characters present by 

 circling the pertinent items in the sentences, or adding percentages 

 to blanks or zeros to the ends of inappropriate sentences. Descriptive 

 phrases applied to various shapes are minimal in number; the observer 

 may have to compose further refinements. But descriptive refine- 

 ments can be overextended to the unnecessary wastage of time, for 

 this checklist applies to initial analysis of the generic position and not 

 to fine details necessary for specific identity. 



One may find it useful to replicate copies of this checklist for the 

 keeping of records. 



BODY 



(Pereon and Pleon [metasome and urosome]) 



General, segments: 



Abnormal disproportion or enlargement (example, Danaella) . 

 Cylindricalization (examples, Colomastigidae, Eophliantidae). 

 Dorsal depression with or without splaying of coxae. 

 Ornamentation : 



Teeth, dorsal and lateral; pereon 1, 2, 3, 4, 5, 6, 7; pleon 1, 2, 3, 4, 5, 6. 

 Spine groups, dorsal, especially on pleon 1, 2, 3, 4, 5, 6. 

 Elongation of metasome: example, is it as long as 5 or 6 pereonites? (for dis- 

 tinguishing a few Gammaridae and Eusiridae). 

 Urosome : 



Coalescence of segments: 1-2, 1-3, 2-3 (examples: Ampeliscidae, Kuriidae 



Podoceridae). 

 Dorsal depression (examples, Corophiidae, Cheluridae). 

 Elongation of urosomite 1 (example, Podoceridae). 

 Pleonal epimera: 



Shape and ornamentation from lateral view, especially of epimeron 3 (primarily 

 for identification to species). 

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