CREASERand CLIFFORD: LIFE HISTORY STUDIES OF SANDWORM 



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(15) (1) 



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(3) (2: (101(101 112*11) (181 



i: NUMBERS OF WORMS INSPECTED 



_i 1 i_ 



OND JFMAMJ JASOND J FMAMJJ 



1966 



1967 



IB) 



1968 



O :MEAN MUD TEMPERATURE A 

 FROM 3 AREAS OF WORM 

 FLAT 



0NDJFMAMJJAS0NDJFMAMJ J 

 I9S6 1967 1968 



Figure 4.— (A) Oocyte growth occurring simultaneously in 

 two groups of Wiscasset sandworms at different stages of 

 maturation (lines fitted by eye). (B) Monthly mean mud and 

 bottom water temperature from the Sheepscot River at Wis- 

 casset. 



Table 1.— Summary of temperature and salinity associated 

 with sandworms spawning at Wiscasset, Maine, on 2 May 1967 

 and 19 April 1968. 



EST) and ending just before low water (14:34 

 EST), no spawning worms were observed until 

 about 3 h after high water (Table 2). Although 

 the possible role of water temperature in initiat- 

 ing spawning cannot be completely eliminated, 



13 l N 50 



1.2 



1.1 



1.0 



.9 



8 



V 



-.6 



CO 



o 



O .5 



LU 



4 

 .3 

 .2 



11- 



E 0464 L 25523 



5 10 15 20 25 30 35 40 45 50 55 60 

 ANESTH LENGTH, CM 



Figure 5.— Number of eggs produced as a function of sand- 

 worm length. 



the tidal-condition results in Table 2 are consis- 

 tent with numerous visual observations on 

 spawning activity in the Wiscasset area over 

 many years. 



Spawning Characteristics 



Nearly all sandworms captured during spawn- 

 ing were males. Females were only rarely en- 

 countered in the latter part of the spawning sea- 

 son. Scuba observations revealed that male 

 sandworms emerge from the mud anterior-end 



Table 2.— Data collected during scuba investigation of tidal 

 conditions between high water and low water at onset of spawn- 

 ing activity on 23 April 1968. 



Temperature 

 (°C) 



Salinity 

 (%o) 



No. 

 worms 



collected 



Surface Bottom Surface Bottom 



Time Tide 

 of height 



dive (m) 



(High water 0828 h EST) 



0910- 3.4 7.3 6 1 24 24 26 64 



0930 

 1010- 2 9 7 6 6 5 25 12 26 24 



1028 

 1103- 2.1 8 1 7 7 24 87 24 74 



1123 

 1200- 1.2 8 8 8.2 24 61 24 69 



1222 

 1305- 06 9.4 9.1 25 16 25 26 



1335 

 1400- 0.5 11.2 10 4 24.72 24 98 



1410 

 (Low water 1434 h EST) 















127 



118 



96 





 

 

 

 

 



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