442 Document heading doi:10.12980/JCLM.2.2014J36 襃 2014 by the Journal of Coastal Life Medicine. All rights reserved. Biological parameters and feeding behaviour of invasive whelk Rapana venosa Valenciennes, 1846 in the south-eastern Black Sea of Turkey Hacer Saglam * , Ertug Düzgünes Karadeniz Technical University, Faculty of Marine Science, Çamburnu 61530, Trabzon, Turkey Journal of Coastal Life Medicine 2014; 2(6): 442-446 Journal of Coastal Life Medicine * Corresponding author: Hacer Saglam, Department of Marine Science and Technology Engineering, Faculty of Marine Science, Karadeniz Technical University, 61530 Camburnu-Trabzon, Turkey. Tel.: +904627522805 E-mail: hacersaglam@yahoo.com Foundation Project: This study was financially supported by the Karadeniz Technical University, Trabzon, Turkey. 1. Introduction Rapa whelk, Rapana venosa Valenciennes, 1846, (R. venosa) is a predator native of Asian waters around Japan, China and Korea. Rapa whelks were first discovered out of its native range in Novorossiysk Bay in the Black Sea in the mid-1940s and spreaded throughout Adriatic [1] , North America, Chesapeake Bay [2] and South America [3] in the recent decades. Ballast water transport of the planktonic larval stage between habitats is the most likely vector of introduction across traditional zoogeographic boundaries. The Asian Rapa whelk can tolerate wide ranges in salinity and temperature and combine with currents, has a high potential for spreading into invaded areas. Rapa whelk reaches sexual maturity at 40 mm size [4] . This whelk is a predatory gastropod feeding mostly on bivalves and themselves can be preyed by lobsters, crabs, sea stars and various fishes, such as cod, dogfish and rays [5] . There are no major predators of invasive adult R. venosa in the Black Sea and the population has become very large and PEER REVIEW ABSTRACT KEYWORDS Rapana venosa, Rapa whelk, Length-weight relationships, Growth type, Feeding behaviour, Black Sea Objective: To determine length-weight relationships, growth type and feeding behavior of the benthic predator Rapa whelk at the coast of Camburnu, south-eastern Black Sea. Methods: Rapa whelk was monthly collected by dredge sampling on the south-eastern Black Sea at 20 m depth. The relationships between morphometric parameters of Rapa whelk were described by linear and exponential models. The allometric growth of each variable relative to shell length (SL) was calculated from the function Y=aSL b or logY=loga+blogSL. The functional regression b values were tested by t-test at the 0.05 significance level if it was significantly different from isometric growth. The total time spent on feeding either on mussel tissue or live mussels was recorded for each individual under controlled conditions in laboratory. Results: The length-weight relationships showed positive allometric growth and no inter-sex variability. Body size in the male population was significantly higher than in the individuals of the female. All characters in males and females showed a trend towards allometry rather than isometry. While the total time spent feeding increased with increasing prey size the total time that Rapana venosa spent feeding decreased with increasing Rapa whelk size. The total average feeding time needed by Rapa whelks was 160 min. But they took 310 min on live mussels in 27-28 °C in the laboratory conditions. Conclusions: Length and weight relationships, growth type, total time spent feeding of this species were explained in details for this region. It would be useful to sustainable management in the south-eastern Black Sea of Turkey. The results about the feeding behaviour of this species will contribute to the understanding of the role of this species within the ecosystem. Peer reviewer D iego G iberto, P h D in B iology, Researcher of the National Council of Scientific Research, Mar del Plata, Argentina. Tel: +54 223 4862586 E-mail: diegogiberto@inidep.edu.ar Comments The paper is of broad interest for scientists working in invasive species and fisheries in the region and around the world. The methodology used in the manuscript is correct, the presentation of results is appropriate. Details on Page 445 Article history: Received 11 Dec 2013 Received in revised form 2 Jan, 2ed revised from 23 Jan, 3rd revised from 15 Feb 2014 Accepted 13 May 2014 Available online 10 Jun 2014 journal homepage: www.jclmm.com