Publication year: 2012-10-29

Publication title: Microdistribution of Faunal Assemblages at Deep-Sea Hydrothermal Vents in the Southern Ocean

Publication authors: Marsh, L., Copley, J.T., Huvenne, V.A.I., Linse, K., Reid, W.D.K., Rogers, A.D., Sweeting, C.J. & Tyler, P.A.

Publication editors: Plos One

Publication year: 2014-04-08

Publication title: Controls on faunal microdistribution and reproductive development in deep-sea chemosynthetic environments in the Antarctic (Doctoral Thesis)

Publication authors: Marsh, Leigh

Publication editors: University of Southampton

Publication year: 2012-01-03

Publication title: The discovery of new deep-sea hydrothermal vent communities in the southern ocean and implications for biogeography

Publication authors: Rogers, A.D.; Tyler, P.A.; Connelly, D.P.; et al.

Publication editors: Plos Biology

Publication year: 2010-02-21

Publication title: Chemosynthetic Ecosystems of the Southern Ocean (CHESSO) – RRS James Cook Cruise 42 – Cruise Report

Publication editors: Dr Alex David Rogers

Publication year: 2013-02-08

Publication title: The Biology of Squat Lobsters

Publication authors: Baba, K.F.; Fujita, Y.; Wehrtmann, S.I.; Scholtz, G.

Publication editors: CSIRO Publishing (Poore, G.; Ahyong, S.; Taylor, J.)

Publication year: 2013-02-08

Publication title: Getting the bigger picture: Using precision Remotely Operated Vehicle (ROV) videography to acquire high-definition mosaic images of newly discovered hydrothermal vents in the Southern Ocean

Publication authors: Marsh, L.; Copley, J.T.; Huvenne, V.A.I.; Tyler, P.A.

Publication editors: Deep Sea Research II: Topical Studies in Oceanography

Specimens of Kiwa tyleri were collected from six biological sampling dives at the E2 and E9 vent fields during RRS James Cook research cruise 42 (7th January - 24th February 2010) using the Isis ROV (remotely operated vehicle) equipped with a suction sampler. Discrete spatial samples were targeted to investigate the fine-scale spatial variation in reproductive biology. Three biological sampling dives were conducted at the E2 vent field and a further three sampling dives at the E9 vent field. Specimens recovered from the ROV were sorted by sex and ovigerous condition. Sex determination was based on the presence of setose pleopods and the presence of the gonopore on the 3rd pereopod of the females. Females that were carrying eggs were determined as ovigerous and the brood was carefully removed. The standard measure of body size for anomurans, carapace length (CL), was determined to the nearest 0.01 mm by vernier calipers for both males and females. CL was measured from the midline of the orbital arch to the mid dorsal posterior margin of the carapace. Female specimens and eggs for reproductive analysis were then fixed in 4% seawater buffered formaldehyde solution before being transferred to 70% ethanol on arrival in the UK. Adult females were dissected and reproductive maturity was assessed by direct visual observation of ovary morphology, colour, and relative size under using a stereomicroscope. To obtain oocyte size-frequency distributions, ovaries were removed by dissection and subsequently imaged using a Leica EZ4HD stereomicroscope. It was not possible to separate individual oocytes without rupturing the oocyte structure. Sections of the gonad were therefore laid as flat as possible onto a petri dish. For inter- and intra- species comparisons, a minimum of 20 Equivalent Circular Diameters (ECD) of both pre-vitellogenic and vitellogenic oocytes were then calculated from calibrated images using ImageJ (version 1.440) image analysis software. ECD represents the diameter of a hypothetical circle of equal area to the object measured, and therefore takes account irregularities in the shape of the oocytes as a result of dense packing in the ovary. The vitellogenic oocytes were not suitable for histological analysis because of their exceptionally large size (maximum measured oocyte 1558 μm) and high neutral lipid content. Subsamples of ovaries from each spatial sample were however examined histologically to confirm pre-vitellogenic development. A small section of the ovary was dehydrated through a series of graded alcohol solutions and cleared in xylene. The tissues was embedded in paraffin wax and sectioned by microtome at 7 μm. Sections were mounted on glass slides and stained with haemotoxylin and eosin. During dissection, criteria presented in Marsh (2014) were used to assign a Reproductive Development Stage (RDS) to each female; (1) Moult stage; (2) Ovary Maturity Stage (OMS); (3) Ovigerous condition; The eggs were staged based on criteria presented in Marsh (2014). Realised fecundity has been defined as the number of eggs carried on the pleopods of each individual. To examine fecundity, the eggs from ovigerous females were enumerated and imaged with the Leica MZ16. Eggs that had not ruptured and had retained the embryonic membrane were measured (egg length (EL) and egg width (EW)) using ImageJ (version 1.440). Late stage eggs take a prolate ellipsoid shape and therefore egg volume (EV) was estimated as EV = 4/3π(EL/2) × (EW/2)^2 (Baba et al., 2011). The data were published in the Published Data Library by the British Oceanographic Data Centre following clarification of metadata with the data originators.

Instrument(s) used to collect data: optical backscatter sensors; underwater cameras; optical microscopes; rulers; Ultra Short Baseline Positioning Systems; CTD.