Sahar Izadi

Large predators typically feed on proportionally sized prey but the world's largest animals, baleen whales, bulk feed on plankton and small fishes. While most baleen whales migrate to feed on polar aggregations of nutritious zooplankton prey, Bryde's whales (Balaenoptera edeni brydei and B. e. edeni) inhabit less productive warm‐temperate waters with variable prey abundance and quality. Off New Zealand, Bryde's whales target both fish and zooplankton, some with lower calorific value. We use multisensor tags (n = 4) and visual observations from drones and boats (n = 52) to reveal that Bryde's whales employ specialized feeding tactics matched to prey type. Zooplankton‐feeding at the surface involved multiple head‐slaps that presumably aggregate zooplankton followed by a side‐lunge. Whales exploiting plankton patches swam in tight circles, performing up to 33 lunges (M = 5.5 ± 6.1) per feeding bout. In contrast, whales targeting fish performed faster vertical lunges. With both prey types, whales concluded lunges with a ~90° roll probably to minimize prey escape at the surface. The diet plasticity and dynamic behaviors of Bryde's whales are key to increasing their foraging efficiency. This may be essential for the whales to meet energetic demands year‐round with a variety of prey in New Zealand waters.

ABSTRACT Mollusc’s community was investigated along 9 intertidal rocky sites around Qeshm Island in August 2010 and January 2011. This survey is a part of a comprehensive study on intertidal invertebrates of Qeshm Island carried out in Persian Gulf Biotechnology Research Centre. In total, 69 taxa belonging to 37 families and 3 classes (gastropoda, bivalvia and polyplacophora) were identified in sampling sites. Differences in mollusc’s biodiversity among sites were studied by depicting dissimilarities of sampling sites according to presence and absence of mollusc species. The results of MDS and cluster analysis displayed clear groups which can be explained by specific characters of sampling sites such as distance to residential area or situation of locations in island. The results of cluster analysis confirmed this grouping as well. In 0.48 similarities, MDS plot showed two distinct groups that separated location 16 and location 24 from other sites. In contrast to other sampling sites, these two sites are located in northern part of the island. Location 5, which is a pristine site, with 35 species showed the most mollusc diversity, while location 16, which is exposed to fisheries activities by locals, was the least diverse site with 19 species. Clypeomorus bifasciatus was found in all sampling sites, while Engina mendicaria, conus sp., Mauritia grayana, Diodora sp., Meduso fissurella sp., Littoraria intermedia, Thais tissoti, Nerita adenensis, Cellana rota, Gryneum sp., Barbatia obliquata, Vasticardium lacunosum, Plicatula plicata, Codakia tigerina, Asaphis violascens, Neotrapezium sublaevigatum, Irus macrophylla, Chiton lamyi, Chiton salihafui and Tonicella sp. was sampled just in one of these 9 sites.