. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 228 Bulletin Museum of Comparative Zoology, Vol. 157, No. 4. Text-Figure 2. Distribution map of species of Xylophaga. ported here. The first case involves varia- tion in response to different substrata, the second case exliibits variation that possibly is genetic because the substrate and all other parameters were as nearly uniforin as possible, and the third case illustrates variation in a normal growth series. Variation Due to Different Substrates. Variation in Xylophaga mashingtona in re- sponse to the substrate ca
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 228 Bulletin Museum of Comparative Zoology, Vol. 157, No. 4. Text-Figure 2. Distribution map of species of Xylophaga. ported here. The first case involves varia- tion in response to different substrata, the second case exliibits variation that possibly is genetic because the substrate and all other parameters were as nearly uniforin as possible, and the third case illustrates variation in a normal growth series. Variation Due to Different Substrates. Variation in Xylophaga mashingtona in re- sponse to the substrate can be deinonstrat- ed with material from the USNCEL tests. A series of 10 panels of different types of wood were attached to a submersible test unit (STU) that was submerged from April 1965 to May 1966 off San Miguel Island, California (34°06'N, 120°42'W) at 2,370 ft (730 m) (see Table 1 and Text-Figs. 3-9). The 2 X 6 X ( X X min) wood panels were all attached to the same rack on the STU so that they would be resting just above the mudline. Con- sequently, all factors affecting the borers were as nearly identical as possible except the substrate (, the species of wood) on i which the borer larvae settled and into j which they would bore. Text-Figures 3—8 illustrate typical specimens from each of the wood panels; Text-Figure 9 shows specimens from a phenolic laminated rod. It is interesting to note that the dorsal plates in all specimens are remarkably uni- form, varying only slightly in length/width proportions. Even the specimens taken from the phenolic laminated rod could be identified by the dorsal plates. The general shape of the valves with the high posterior slope also remained rather constant except in the extremely steno- morphic (stunted) specimens from Afam- beaii and the phenolic laminated rod. It is difficult to explain the proportionate size of the larval valves on specimens boring into harder materials except that these speciinens had
Size: 1894px × 1319px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorharvarduniversitymuseumofcomparat, booksubjectzoology
