Ikeda: Energy budget of Maurolicus muellen 



53 



Energy invested in reproduction is partly included 

 in G in the present calculation (e.g. G is derived from 

 intact fishes including gonads, but neither eggs nor 

 sperm already released were included). The great- 

 est proportional weight of gonads for M. muelleri in 

 Toyama Bay has been reported as 10% of WW for 

 females and 6%> of WW for males (recalculated from 

 gonad index data in Ikeda, 1994). From the caloric 

 content of adults given in Table 2 (1.47 Kcal/g WW) 

 and those of ovaries (1.12 Kcal/g WW) and testes ( 0.93 

 Kcal/g WW) in Table 3, the proportions of energy in 

 the form of ovaries and testes were computed as 7.6% 

 (10 x 1.12/1.47) and 3.8% (8.6 x 0.93/1.47), respec- 

 tively, of G (1,820 cal) in 1.8-yr-old fish (53 mm TL). 

 When M is combined with G (i.e. assimilated energy: 

 1,820 + 9,075 cal), the fraction of energy stored in 

 gonads becomes 1.3% for females and 0.6 % for males. 

 Alternatively, energy invested in egg production in 

 females may be estimated by knowing the number 

 of mature oocytes. The DW of single mature oocytes 

 is 34 ng (±1.76, n=5), and the maximum number 

 counted for M. muelleri in Toyama Bay is 283 ( Ikeda, 

 1994). These figures, combined with calorific content 

 of the oocytes (5.61 Kcal/g WW, Table 4) yield 54.0 

 cal (34 x 10 -6 x 5.61 x 10 3 x 283), which corresponds 

 to 0.5% of energy assimilated (1,820 + 9,075 cal) by 

 1.8-yr-old fish. 



T(°C) 



Figure 2 



Relationship between ETS activity (ETS: /*L 2 /(mg 

 WWh)) and temperature ("Offish 1: 442 mg WW, and 

 fish 2: 472 mg WW) for Maurolicus muelleri. Slopes are 

 not significantly different U-test, P>0.05). 



