A48.05 Marine Borers 



1. Teredinidae . Teredlnldae , including Bankia havailenals . 

 Teredo af finis . T. milleri . T. parksi . T. trulllformis , T. ( Lyrodus ) 

 diegensis , T. ( Lyrodus ) sp. , and T. sp . , vere very active at all f our 

 locations throughout the period covered "by the test. The severity of 

 attack was such that it was requested in November 19^ that all panels 

 ■be removed from the test "boards and replaced with panels 2 inches 

 thick. This change was made in Decemlier. However, increasing the 

 thickness of the panels did not prolong their length of life, since 

 the attack was Just as severe proportionately in the two-inch panels as 

 in the one- inch panels. In Novemljer 19^5 it was requested that all 

 liaAels on the test "boards "be removed and that a new series "be insteilled 

 and pperated on a 4-month "basis instead of on the 8-month "basis which 

 was ))eing employed. The change to the new series of panels was made 

 in IJiebeaaber. The detailed figures on the occurrence of Teredinidae 

 at each of these locations are summarized "below. 



a. USHH-l (Tim"ber Wharf ). Tered.inidae occurred in all 4l 

 control panels, ranging from minute pits or embryonic specimens to 

 specimens up to 50 nm in length. Five of these panels were 40^, 50^* 

 ^^r l^i>t and 90^ filled, respectively. The "breeding season was 

 continuous. Teredinidae also occurred in all except 5 of the k-8 test 

 panels, none occurring in the first 2 panels or in the first one in the 

 new series installed when the change was made to thicker panels in 

 December 19^. A maximum length of 250 mm (lO inches) was recorded 

 in a panel su'bmerged for 7 months. Thirty-eight of the k-8 test panels were 

 either filled or riddled, although most of them had "been submerged for 

 only k months. One. test panel "became riddled in as short a period as 2 

 months. The attack was extremely destructive each year, Including 19^. 



"b. T3SMH-2 (lOlO Wharf ). Teredinidae occurred in all 4l 

 control panels, ranging from minute pits or em"bryonic specimens to those 

 up to 25 mm in length. Two of these panels were 50^ and ^t-O^ filled, 

 respectively. The "breeding season was continuous. Teredinidae also 

 occurred in all 48 test panels, with a maxlTmim length of 220 mm 

 (a"bout 9 inches) recorded in a panel su'bmerged for 3 months. Nineteen 

 test panels were either filled or riddled, although most of them had 

 "been su'bmerged for only k months. One of these panels "became filled 

 within 5 months. The attack was extremely destructive each year, including 

 1944. 



c. IJSM-5 (DE Wharf ). Teredinidae occurred in all except 

 2 of the 4l control panels, ranging from minute pits or em"bryonlc 

 specimens to those up to 25 mm in length. The "breeding season was 

 continuous. Two of these panels were 40^ filled, and 2 were completely 

 filled. Teredinidae occurred in all 48 test panels, with a maximum 

 length of 240 mm (a"bout 9z inches) recorded in a panel suhmerged for 4 

 months. 



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