FISHERY BULLETIN: VOL. 72, NO. 1 



Poiitc'lliiiii pUttychela 

 (Figures 17b, f, j; 18b, f, j, n) 



Copepodite stage V female: Th x 1.37 mm, 

 range 1.18-1.46 mm. 10 specimens. ThV postero- 

 lateral corners rounded and ending in a small 

 denticle (Figure 17b) as in adult. Furcal rami 

 (Figure 170 and P5 (Figure 17j) resembling 

 those of p/«»mfa. _ 



Copepodite stage V male: TL x 1.30 mm, 

 range 1.24-1.36 mm, 10 specimens. Margin of 

 posterolateral corner of ThV with weak denticle 

 (Figure 18b, n). P5 with distinctive right leg 

 (Figure 18j). Re considerably broader than in 

 the other three species, about 1.6 times as long 

 as wide. Furcal rami (Figure 18f) as in plianata. 



Poiitelliiui niorii 



(Figures 17c, g, k; 18c, g, k, q) 



(Notes based on specimens from localities in the 

 Indian Ocean.) 



Copepodite stage V female: TL x 1.28 mm, 

 range 1.18-1.36 mm, 10 specimens. ThV corner 

 typically with a small spiniform point (Figure 

 17c) resembling that in the adult. Ri of P5 

 (Figure 17k) longer than in plumata (Figure 

 21), typically with 2 spines; Re:Ri length ratio 

 considerably less (median 2.1:1, range 1.7- 

 2.6:1, 20 specimens) than in plumata (Figure 

 22). Furcal rami symmetrical (Figure 19), 

 shorter than those in plumata (Figure 20), as 

 in sexually mature stages. Medial setalike pro- 

 cess of Re of left P5 (Figure 17k) more abruptly 

 bent (~90°) than that of the other three species 

 (Figure 17i). 



Copepodite stage V male: TL x 1.21 mm, 

 range 1.12-1.32 mm, 10 specimens. Postero- 

 lateral corner of ThV ending in a relatively 

 short spiniform point (Figure 18c, q) about one- 

 half the length of that in sobrina (Figure 18d, 

 o) and much less robust than that in plumata 

 (Figure 18a, p). Di.stal segment of right P5 

 distinctly bent mediad (Figure 18k). Furcal 

 rami (Figure 18g) similar in relative length and 

 width to those in female. 



Pontell/ua sohr/i/ii 



(Figures 17d, h, 1; 18d, h, 1, o) 



(Notes based on juvtMiilc specimens from eastern- 

 most Pacific localities which were accompanied 

 by large numl)ers of adults; the localities are rela- 

 tively distant from those yielding worii.) 



Copepodite stage V female: TL x 1.25 mm, 

 range 1.18-1.34 mm, 10 specimens. Differences 

 between sexually immature sobrina and morii 

 females are relatively weak, e.g., greater length 

 of the ThV point (Figure 17d) and the weaker 

 bend of the medial setalike i)rocess on the left 

 Re of P5 (Figure 171), appear to be useful, but 

 lack confirmation by measurements from a 

 geographically representative series of 

 specimens. 



Copepodite stage V male: TL F 1.25 mm. 

 range 1.12-1.38 mm, 10 specimens. Postero- 

 lateral corner of ThV produced into a relatively 

 long slender point (Figure 18d, o). Right P5 

 with .straight distal segment resembling that 

 in plumata, but all segments in P5 of sobnjui 

 appear slightly wider. 



Sex Ratios 



In laboratory-reared populations sex ratios 

 among adult copepods of several families have 

 been found to vary widely (for recent comments 

 see Heinle, 1970; Katona, 1970; Paffenhdfer, 

 1970). In natural populations, however, late 

 immature copepodids have been found to pro- 

 duce males and females in about equal numbers 

 (Marshall. 1949). Among randomly sorted, 

 sexually mature adults of the four species of 

 Poutelliiia females consistently outnumbered 

 males by roughly 1.3: 1 (Table 4). 



Assuming that the sexes are genetically one 

 to one, the observed male-to-female ratios in 

 Poutelliua could be readily accounted for if 

 females live longer than males, a likelihood 

 suggested by many authors for various ampha- 

 scandrid copepod genera. In a small series 

 of rearing experiments on Labidocera trispi)iosa, 

 A. Barnett (pers. comm., 1972) has found that 

 following the adult moult females live 2 to 3 

 wk and males about 1 wk. 



Table 4. — Frequency of sexually mature individuals and 

 sex ratios in Pontcllina. 



1 One sample, i.e., Allanlis II 20-42, was omitted because it 

 provided the extremely disproportionate capture of 327 moles 

 and 10 females. 



92 



