[en] CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2⁰C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2⁰C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10⁰C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10⁰C. Yet reproduction is enhanced above 280 bars and occurs with a regeneration time of 4 hours at 690 bars and 7 hours at 930 bars. (4) The loss of colony forming ability at 10⁰C is very slow but very rapid at 32⁰C with 10⁶ colony forming units being lost in less than one hour. The activation energy for thermal inactivation was 43 Kcal. Two hypotheses may be tenable One is that most of the important deep-sea abyssal plain bacteria are barophilic. The other is that most of the published literature on the properties and characteristics of deep-sea bacteria has been generated with spurious deep-sea bacteria. At the end of the year cultures of CNPT-3 were irradiated with cobalt-60 gamma rays. Early results suggest that it may not be unusually radiosensitive. Technique development this year included: completion of the first stage of a high pressure microbial cultivation facility; procurement of the first stage of an image analysis system; and, completion of the fabrication of two pressure retaining amphipod traps