Discovery reports (1937) Discovery reports discoveryreports14inst Year: 1937 Fig. 13. Development of the antenna (x 46). a, larva with 5 telson spines; c, larva 9-71 mm. long with 3 telson spines; b, larva 9-16 mm. long with 3 telson spines; d, larva 11-30 mm. long with 3 telson spines. In the statement of the number of segments in the inner ramus of the antenna of the larvae from St. 374 (Table XX) the number has been expressed as the sum of two, of which the first indicates peduncular and the second flagel- lar segments. In Table XXIII the length frequency of the larvae according to the nu
Discovery reports (1937) Discovery reports discoveryreports14inst Year: 1937 Fig. 13. Development of the antenna (x 46). a, larva with 5 telson spines; c, larva 9-71 mm. long with 3 telson spines; b, larva 9-16 mm. long with 3 telson spines; d, larva 11-30 mm. long with 3 telson spines. In the statement of the number of segments in the inner ramus of the antenna of the larvae from St. 374 (Table XX) the number has been expressed as the sum of two, of which the first indicates peduncular and the second flagel- lar segments. In Table XXIII the length frequency of the larvae according to the number of terminal spines in the telson and the state of the inner ramus of the antenna are given. None of the seven- or six-spined larvae possess segmented antennal inner rami. Among five-spined larvae 89-7 per cent have unsegmented and 10-3 per cent have segmented antennal inner rami. The number of four-spined larvae is incon- siderable but all have segmented inner rami. By the time the larvae are three-spined, only a very small minority are unsegmented, and in the two- and one-spined larvae no unsegmented antennae occur. The analysis shows therefore that the change in the form of antenna is not restricted to one stage but may take place in five-spined or Fig. 14. Segmentation of antennal inner ramus. three-spined larvae. It also shows that, within a,Thysanoessa maoura; b,Eiiphausiafrigida; c, E. siiperba. Diagrammatic, a and b after Rustad.
Size: 1506px × 1328px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
