Male Choice in the Stream-Anadromous Stickleback Complex

Studies of mating preferences and pre-mating reproductive isolation have often focused on females, but the potential importance of male preferences is increasingly appreciated. We investigated male behavior in the context of reproductive isolation between divergent anadromous and stream-resident populations of threespine stickleback, Gasterosteus aculeatus, using size-manipulated females of both ecotypes. Specifically, we asked if male courtship preferences are present, and if they are based on relative body size, non-size aspects of ecotype, or other traits. Because male behaviors were correlated with each other, we conducted a principal components analysis on the correlations and ran subsequent analyses on the principal components. The two male ecotypes differed in overall behavioral frequencies, with stream-resident males exhibiting consistently more vigorous and positive courtship than anadromous males, and an otherwise aggressive behavior playing a more positive role in anadromous than stream-resident courtship. We observed more vigorous courtship toward smaller females by (relatively small) stream-resident males and the reverse pattern for (relatively large) anadromous males. Thus size-assortative male courtship preferences may contribute to reproductive isolation in this system, although preferences are far from absolute. We found little indication of males responding preferentially to females of their own ecotype independent of body size

Fish Intelligence, Sentience and Ethics

Fish are one of the most highly utilised vertebrate taxa by humans; they are harvested from wild stocks as part of global fishing industries, grown under intensive aquaculture conditions, are the most common pet and are widely used for scientific research. But fish are seldom afforded the same level of compassion or welfare as warm-blooded vertebrates. Part of the problem is the large gap between people’s perception of fish intelligence and the scientific reality. This is an important issue because public perception guides government policy. The perception of an animal’s intelligence often drives our decision whether or not to include them in our moral circle. From a welfare perspective, most researchers would suggest that if an animal is sentient, then it can most likely suffer and should therefore be offered some form of formal protection. There has been a debate about fish welfare for decades which centres on the question of whether they are sentient or conscious. The implications for affording the same level of protection to fish as other vertebrates are great, not least because of fishing-related industries. Here, I review the current state of knowledge of fish cognition starting with their sensory perception and moving on to cognition. The review reveals that fish perception and cognitive abilities often match or exceed other vertebrates. A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates. Although scientists cannot provide a definitive answer on the level of consciousness for any nonhuman vertebrate, the extensive evidence of fish behavioural and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Resection margin in laparoscopic hepatectomy: a comparative study between wedge resection and anatomic left lateral sectionectomy

AbstractBackgroundExperience from open hepatectomy shows that anatomic liver resection achieves a better resection margin than wedge resection. In recent years, laparoscopic hepatectomy has increasingly been performed in patients with liver pathology including malignant lesions. Wedge resection (WR) and left lateral sectionectomy (LLS), which also represent non-anatomic and anatomic resection respectively, are the two most common types of laparoscopic hepatectomy performed. The aim of the present study was to compare the two types of laparoscopic hepatectomy with emphasis on resection margin.MethodsBetween November 2003 and July 2009, 44 consecutive patients who underwent laparoscopic hepatectomy were identified and retrospectively reviewed. The WR and LLS group of patients were compared in terms of operative outcomes, pathological findings, recurrence patterns and survival.ResultsOut of the 44 patients, 21 underwent LLS and 23a WR. The two groups of patients were comparable in demographics. The two groups did not differ in conversion rate, blood loss, blood transfusion, mortality, morbidity and post-operative length of stay. The LLS group patients had significantly larger liver lesions, wider resection margin and less sub-centimetre margins. In patients with malignant liver lesions, there was no difference between the two groups in incidence of intra-hepatic recurrence and 3-year overall and disease-free survival.ConclusionOperative outcomes are similar between laparoscopic WR and LLS. However, WR is less reliable than LLS in achieving a resection margin of more than 1cm. Larger studies involving more patients with longer follow-up are warranted to determine the impact of the resection margin on intra-hepatic recurrence and survival