Invertebrates worms

This chapter reviews the history of a remarkable family of natural products first isolated from the marine tube-inhabiting invertebrate worm Cephalodiscus gilchristi. C. gilchristi, found in the temperate Southern Hemisphere, is often attached to bryozoans and sponges. This tiny worm ( 5 mm in tube colonies) can exist independently of the coenicium (worm tube), and exposure to predators during such moments may have aided the evolution of chemical defence mechanisms. 

FIGURE 6.7 The three-dimensional structures of two proteins that contain substantial amounts of rx-helix in their structures. The helices are represented by the regularly coiled sections of the ribbon drawings. Myohemery-thrin is the oxygen-carrying protein in certain invertebrates, including Sipunculids, a phylum of marine worm. (Jane Richardson)... 

Trivalent chromium was less effective than Cr+6 in reducing fecundity of Daphnia magna 44 pg Cr+VL vs. 10 pg Cr+6/L (USEPA 1980). Annelid worms (Tubifex sp.) accumulated about 1 mg total chromium/kg whole body during exposure for 2 weeks in sediments containing 175 mg ( T+3/kg, suggesting that benthic invertebrates have only a limited ability to accumulate chromium from sediments or clays (Neff et al. 1978). 

The distribution of aquatic species sensitivities to cypermethrin is typical of SPs [7] (Giddings JM (2006) Compilation and evaluation of toxicity data for synthetic pyrethroids. Unpublished report of Compliance Services International, Rochester). Crustacean and insect species (from the phylum Arthropoda) tend to be more sensitive to pyrethroids compared to other invertebrates such as worms and mollusks, and fish tend to be less sensitive than arthropods. These sensitivities are... 

Assuming that the mammal or bird feeds on soil invertebrates (e.g., worm-eating birds or mammals), the simplest model to calculate an MPC based on this food web is... 

This supports our earlier work with invertebrates which were exposed to lower concentrations of oil in the laboratory or selected at a refinery outfall site (7). We recently noted that annelid polychaetes (sandworms) collected near this refinery had slightly higher AHH activity levels than worms from a control site, but attempts to stimulate activity in "control" worms with oiled sediments have been unsuccessful. 

Baculoviruses are members of a large group of double-stranded DNA viruses which only infect invertebrates, including insects. The restricted host range makes baculoviruses safer than mammalian expression systems. The most widely used baculoviruses are Autographa califor-nica nuclear polyhedrosis virus and the Bombyx mori nuclear polyhedrosis virus. The host cell most commonly used is Sf9, derived from the fall army worm Spodoptera frugiperda. 

Resting Membrane Potential A variety of unusual invertebrates, including giant clams, mussels, and polychaete worms, live on the fringes of hydrothermal vents on the ocean bottom, where the temperature is 60 °C. 

While the hydra is almost immortal as a result of the continuous differentiation of its stem cell lines, other small invertebrates follow a very different course of development. Both the rotifers and the annelid worms (Fig. 1-14) tend to have a constant number of cells in the adult body. The entire developmental program is specified genetically in strict detail. 

Bayne, C.J. (1998) Invertebrate cell culture considerations insects, ticks, shellfish, and worms. Methods in Cell Biology 57, 1 87-201. 

---