Sepiolida'nın (Mollusca: Cephalopoda) karşılaştırmalı üreme biyolojileri

Güneybatı Atlantik’ten Semirossia patagonica (104 birey) ve Neorossia caroli jeannae (27 birey); Akdeniz’den de Rossia macrosoma (189 birey) ve Neorossia caroli’ye (13 birey) ait örneklerin üreme özellikleri incelenip diğer sepiolidlerle karşılaştırılmıştır. Akdeniz’den örneklenmiş olan türlerden R. macrosoma’nın potansiyel fekonditesi 126 – 946 arasında, spermatofor sayıları 15 -103 arasında bulunurken N. caroli’nin potansiyel fekonditesi 551 – 608 arasında, spermatofor sayıları 20 -74 arasında bulunmuştur. Güneybatı Atlantik’ten örneklenen S. patagonica’nın potansiyel fekonditesi 7 – 766 arasında, spermatofor sayıları 2 – 229 arasında; N. caroli jeannae’nin potansiyel fekonditesi 215 – 827 arasında ve spermatofor sayıları 9 – 16 adet arasında bulunmuştur. Rossinae subfamilyası üyelerinin Sepiolinae üyelerine göre daha yüksek potansiyel fekonditelere ve daha büyük yumurta çaplarına sahip oldukları bulunmuştur. N. caroli’nin Güneybatı Atlantik’teki alt türü N. caroli jeannae’den daha yüksek potansiyel fekonditeye sahip olmasına karşılık daha küçük yumurta çaplarına sahip olduğu görülmüştür. Bunun sıcaklık farkından ötürü oluşan bir uyum olduğu düşünülebilir. İncelenen bütün örneklerin grup-senkronik ovülasyona ve aralıklı ve/veya sürekli yumurtlamaya sahip oldukları tahmin edilmektedir

Length weight relationships of coleoid cephalopods from the eastern Mediterranean

Abstract Length-weight relationship (LWR) studies have been widely conducted for fish. They are important because they provide information about the growth of the fish, its general wellbeing, and fitness in a marine habitat. In comparison, relatively few LWR studies have been conducted on cephalopods. A total of 13,474 specimens belonging to 28 cephalopod species was investigated to define their length–weight relationship status and Fulton’s condition factors, and compared with previous studies to evaluate life history traits and test comparability of LWR values. Isometry was found in 8 species including 2 teuthids, 2 sepiids and 4 octopods, and positive allometry was found in 2 squid species. Other species showed negative allometry. Four orders of the class Cephalopoda distributed in the Mediterranean Sea were also compared in respect of their coefficient b values, and a clear distinction was found between the orders reflecting their characteristic body types and thus lifestyles. Coefficient b values of mature animals were found lower than that of maturing ones that reflects growth of semelparous cephalopods stops or at least slows down when they reach maturity. Some extreme condition factor values were calculated for especially octopods that one of them reached to 140.91 in a deep-sea octopus Pteroctopus tetracirrhus. It suggests that there are many factors that might affect the calculations. Some of them were: different body structure and growth type in cephalopods than that of fish, different length measurement method applied in cephalopods, different body parts that might have different growth rates, and preservation methods that could affect the body shape and weight in soft bodied animals

Are introduced gibel carp Carassius gibelio in Turkey more invasive in artificial than in natural waters?

GAYGUSUZ, Ozcan/0000-0001-6861-6221; Copp, Gordon/0000-0002-4112-3440; Gaygusuz, Ozcan/0000-0001-6861-6221; Sac, Gulsah/0000-0001-9988-1116; Yapici, Sercan/0000-0003-2288-5084; Tarkan, Ali Serhan/0000-0001-8628-0514; Filiz, Halit/0000-0003-0096-6123WOS: 000301429900009The underlying mechanisms responsible for ecological plasticity and consequent invasive character of non-native freshwater fish species, variations in growth and life history traits in gibel carp Carassius gibelio (Bloch) were compared in natural and artificial water bodies of Turkey. Females significantly outnumbered males in all natural and most artificial waters. Discriminate function analysis differentiated gibel populations into three separate groups (natural lakes, artificial water bodies and running waters), with significant differences among separated groups in growth index, standard length and age at maturity, relative fecundity and gonado-somatic index, but not in egg diameter and both generalised and relative condition. Growth features (e.g. growth index and relative condition) and reproductive features (e.g. relative and absolute fecundity) positively correlated with water body area. No correlations were found for any growth or life history trait with depth, latitude and altitude. With the exception of smaller size at maturity, all traits were higher in populations from artificial water bodies than those inhabiting running waters, suggesting gibel carp is required to exert more reproductive effort to invade natural ecosystems than artificial waters.Mugla UniversityMugla Sitki Kocman University [09/28]; Istanbul UniversityIstanbul University [BYPF-6-6/160606]; UK Department for Environment, Food & Rural Affairs (Defra)Department for Environment, Food & Rural Affairs (DEFRA)Elaborated within the framework of an international network initiated with a NATO Science Programme 'Collaborative Linkage Grant' (awarded to GHC) on the use of life-history traits to assess the risks of non-native fishes, the present study was funded jointly by Mugla University (Project No: 09/28), Istanbul University (Project No: BYPF-6-6/160606), with the participation of GHC funded by the UK Department for Environment, Food & Rural Affairs (Defra). Special thanks go to N. Gokalp and members of Ildeniz Fisheries for assistance in the field