In Sepia officinalis (Linnaeus, 1758), the digestive gland matures during the first month post-hatching, while a shift from intracellular acid to extracellular alkaline digestion occurs. The purpose of this study was to investigate the possibility of using enzymatic ratios for the description of digestive system maturation in early life stages of S. officinalis. Second, it is intended to apply these new tools as eco-physiological indicators for understanding the impact of cuttlefish eggs' life history from different spawning sites of the English Channel on digestive performance of juveniles. An experimental rearing was performed over 35 days after hatching (DAH) on juveniles from wild collected eggs in 2010 and 2011. Four digestive enzyme activities and their ratios [i.e., trypsin, cathepsin, acid (ACP), and alkaline (ALP) phosphatase, ALP/ACP, and trypsin/cathepsin] were studied along with histological features (e.g., internal yolk surface and digestive gland development). The two enzyme ratios were good indicators of digestive system maturation allowing the study of the digestive gland's development. They were highly correlated to juveniles' weight increase and histological features of the gland in early DAH. These ratios described more accurately the shift occurring between the intracellular acid and the extracellular alkaline modes of digestion in S. officinalis and were more specific than separated enzyme activities. Their application as eco-physiological tools revealed that enzyme ratios reflected yolk content and digestive gland development in new hatching juveniles. Finally, ALP/ACP ratio was shown to be a powerful tool to describe growth performance of S. officinalis which is useful for aquaculture optimization.

Embryonic and early postembryonic development of the cuttlefish Sepia officinalis (a cephalopod mollusk) occurs in coastal waters, an environment subject to considerable pressure from xenobiotic pollutants such as pharmaceutical residues. Given the role of serotonin in brain development and its interaction with neurodevelopmental functions, this study focused on fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI, antidepressant). The goal was to determine the effects of subchronic waterborne FLX exposure (1 and 10 μg L−1) during the last 15 days of embryonic development on neurochemical, neurodevelopmental, behavioral, and immunological endpoints at hatching. Our results showed for the first time that organic contaminants, such as FLX, could pass through the eggshell during embryonic development, leading to a substantial accumulation of this molecule in hatchlings. We also found that FLX embryonic exposure (1 and 10 μg L−1) (1) modulated dopaminergic but not serotonergic neurotransmission, (2) decreased cell proliferation in key brain structures for cognitive and visual processing, (3) did not induce a conspicuous change in camouflage quality, and (4) decreased lysozyme activity. In the long term, these alterations observed during a critical period of development may impair complex behaviors of the juvenile cuttlefish and thus lead to a decrease in their survival. Finally, we suggest a different mode of action by FLX between vertebrate and non-vertebrate species and raise questions regarding the vulnerability of early life stages of cuttlefish to the pharmaceutical contamination found in coastal waters.

Octopus maya is the main species caught in Mexico. From September 2007 to June 2008, its sex ratio, reproductive season, frequency of non-vitellogenic and vitellogenic oocytes, reproductive indices, and size and weight at maturity, were evaluated. The monthly sex ratio was significantly different from 1:1. The major reproductive season occurs during February to June (dry season) in Yucatan. May-June is the common reproductive season to both Yucatan and Campeche populations. Higher frequencies of vitellogenic oocytes (> 50%) were found from January-March and in May. From five reproductive indices, only the macroscopic and microscopic maturity indices were the best descriptors of the reproductive season in females, whilst only the reproductive complex index was the best descriptor in males. The weight at sexual maturity (BW50%) was 335 g for females and 242 g for males. The size at sexual maturity (DML50%) was 12.58 cm for females and 7.42 cm for males. It is recommend revising the minimum catch size by following these results. The reproductive traits here evaluated could contribute to the recently created Plan for Management of Octopus Fisheries, in particular action line no. 1.4, which refers to protection of females during breeding, and to their protection throughout the entire reproductive season.

Within the English Channel, the common cuttlefish Sepia officinalis is a semelparous species for which a 2-year life cycle was exclusively described in the 1980s. In the 1990s, new research indicated that whilst a 2-year life cycle was still evident for females and the large majority of males, a small proportion of males were actually maturing at only 1 year of age. Since 1980, the interest of French and UK fishers for this resource has increased and it is nowadays one of the most important demersal species of the area and is considered to be fully exploited. From the start of the 20th century, fishing effort and sea surface temperatures have increased in the English Channel and have probably impacted the life history traits of S. officinalis. A 2-year sampling programme was undertaken at French landing sites of the English Channel during the reproduction season in 2010 and 2011 to estimate if the proportion of 1-year-old mature animals has changed. Age determination was carried out by coupling polymodal decomposition and lipofuscin measurement. Size-at-maturity for each year and each sex was estimated by fitting a binomial error GLM. Results highlight that a variable percentage of males and females belonging to the first cohort are mature and that size-at-maturity was lower than that observed in the 1990s. Finally, different parameters, such as temperature and fishing pressure are explored to discuss changes in life history traits suggesting that cuttlefish could be an indicator of the temperature regime shift in the English Channel.

Variations in progesterone (P-4) and testosterone (T) levels in the gonad of Octopus maya from Sisal in Yucatan State, Mexico, were investigated by radioimmunoassays and in relation to four gonad maturation stages (GMS) and to the reproductive cycle, as represented by two maturity indices (microscopic MiMI' and macroscopic MaMI'). According to the GMS and the maturity indices, the reproductive season of O. maya from Yucatan occurred from February to June. In females, P-4 and T displayed the same pattern, with a tendency to increase at the same time, although on average, P-4 had seven-fold higher concentrations than T. In contrast, P-4 and T in male gonads displayed a different pattern, where T concentrations were relatively stable throughout all of the study months. In the female gonad P-4 was lowest (close to 0pgg(-1)) during both developing (GMS-I) and maturing (GMS-II) stages, and increased (189 +/- 53pgg(-1)) approaching the mature stage (GMS-III) to a maximum value of 611pgg(-1). Concentrations of T in the male gonad were lowest (106 +/- 9pgg(-1)) during the maturing stage (GMS-II) and increased up to the mature stage (GMS-III), reaching a maximum of 440pgg(-1). Pearson's correlation (r) between hormones and maturity indices showed strong relationships for females (around 0.4 and -0.7; p<0.05), but there were negligible or weak relationships for males (0.2 and -0.1; p>0.05). Hormone correlations in females were inverse with MaMI and direct with MiMI. Our major findings showed that gonadal P-4 levels were elevated during GMS-III and GMS-IV (i.e. periods of vitellogenic oocytes), where the characteristic aspect is an ovary with very high oocyte diameters, with the primary follicle cells deeply infolded in the ooplasm for yolk synthesis. These results suggested a synchrony between P-4 and the process of folliculogenesis, and in turn, vitellogenesis.

Although cephalopod early life stage development often occurs in coastal areas where contamination is real and continuous, the physiological perturbations induced by contaminants have been rarely investigated. This study focused on the Zn as it is one of the trace metals the most concentrated in coastal waters, worldwide. As Zn-tolerance limits were unknown in juvenile Sepia officinalis, the aim of this study was to estimate the threshold inducing mortality during the 2-first weeks post-hatching, and to determine its sensitivity using digestive and immune enzymatic assays, as well as growth and behavior follow-up during the first 5 weeks post-hatching. Our study highlighted a Zn-mortality threshold lying between 185 and 230 μg l−1, and growth reductions occurring after 5-week at 108 μg l−1 and above, associated with enzymatic perturbations. These results underline a relatively important sensitivity of juvenile cuttlefish to Zn, pointed out by a wide diversity of biomarkers.

Little is known about the immune system of cephalopods, in spite of their many highly derived characters within the molluscan clade, including a vertebrate-like high-pressure closed circulatory system. Further the economic importance of cephalopod fisheries, potential for aquaculture, and use as ecotoxicology models demand a thorough understanding of their immune system. In this study, we present a comprehensive characterization of hemocytes in the common cuttlefish Sepia officinalis. Cytological stainings, electron microscopy- and flow cytometry-observations highlight a single granulocyte population with various densities of eosinophilic granules and unstained vesicles. These hemocytes contain acid phosphatase-, lysozyme- and proPO system enzymes, and have high activity in bead phagocytosis assays. Interestingly, bead pre-incubation in plasma results in time-dependent aggregation perhaps resulting from hemocyanin-coating, and decrease in phagocytosis. This study provides the basis for understanding hemocyte-mediated immunity in the common cuttlefish, and essential background for future studies on cephalopod immunity.

Cephalopod Culture is the first compilation of research on the culture of cephalopods. It describes experiences of culturing different groups of cephalopods: nautiluses, sepioids (Sepia officinalis, S

In this study, we investigated the changes of 13 trace metal and metalloid concentrations (i.e. Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, V, Zn) and their subcellular fractionation in juvenile cuttlefish Sepia officinalis reared in controlled conditions between hatching and 2 months post-hatching. In parallel, metallothionein concentrations were determined. Our results highlighted contrasting changes of studied metals. Indeed, As and Fe concentrations measured in hatchlings suggested a maternal transfer of these elements in cuttlefish. The non-essential elements Ag and Cd presented the highest accumulation during our study, correlated with the digestive gland maturation. During the 6 first weeks of study, soluble fractions of most of essential trace metals (i.e. Co, Cr, Cu, Fe, Se, Zn) slowly increased consistently with the progressive needs of cuttlefish metabolism during this period. In order to determine for the first time in a cephalopod how metal concentrations and their subcellular distributions are impacted when the animals are trace metal-exposed, we studied previously described parameters in juveniles exposed to dissolved Zn at environmental (i.e. 50 μg l(-1)) and sublethal (i.e. 200 μg l(-1)) levels. Moreover, oxidative stress (i.e. glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase activities, and lipid peroxidation (LPO)) was assessed in digestive gland and gills after 1 and 2 months exposures. Our results highlighted no or low ability of this stage of life to regulate dissolved Zn accumulation during the studied period, consistently with high sensitivity of this organism. Notably, Zn exposures caused a concentration-dependent Mn depletion in juvenile cuttlefish, and an increase of soluble fraction of Ag, Cd, Cu without accumulation modifications, suggesting substitution of these elements (i.e. Mn, Ag, Cd, Cu) by Zn. In parallel, metallothionein concentrations decreased in individuals most exposed to Zn. Finally, no perturbations in oxidative stress management were detected in gills, whereas modifications of GST, SOD and catalase activity levels were recorded in digestive gland, resulting in an increase of LPO content after a 6-week exposure to low Zn concentration. Altogether, these perturbations are consistent with previously described high sensitivity of juvenile cuttlefish towards Zn. Our results underlined the need to study deeply contamination impact on this animal at this stage of life.

The immune system of cephalopods remains poorly understood. The aim of this study was to determine the specific activity of immune enzymes in epithelial barriers, circulatory and digestive systems of the common cuttlefish Sepia officinalis. Three enzyme groups with putative functions in immunity were investigated: phenoloxidases (POs), lysozymes and protease inhibitors (PIs). Consistent with a role in immunity, highest PO activities were found in the integument as well as the respiratory and circulatory organs under zymogenic (proPO) and active form. Surprisingly, high PO activities were also found in the digestive gland and its appendages. Similarly, high lysozyme activities were detected in the integument and circulatory organs, but also in the posterior salivary glands, highlighting the implication of this antibacterial enzyme group in most tissues exposed to the environment but also within the circulatory system. Albeit highest in digestive organs, the ubiquitous detection of PI activity in assayed compartments suggests immune function(s) in a wide range of tissues. Our study reports proPO/PO, lysozyme and PI distributions in S. officinalis body compartments for the first time, and thus provides the fundamental basis for a better understanding of the humoral immune system in cephalopods as well as invertebrates.

The French part of the continental shelf of the Bay of Biscay (northeast Atlantic) is the habitat of an anchovy (Engraulis encrasicolus L.) population of scientific interest because of its economic importance and the trend towards greater interannual fluctuations in its abundance, particularly as a consequence of variations in recruitment.Each year a 1-month survey of this population and its pelagic environment is undertaken.Among the descriptors of ecosystem function characterized, mesozooplankton aspartate transcarbamylase (ATC) activity is measured with the goal of defining overall productivity of the mesozooplankton communities.Diverse physical forcing factors are responsible for the enhancement of productivity in the Bay of Biscay, and their respective influences vary at interannual scales.We present the results of ATC activity measurements carried out within the anchovy habitat during six consecutive breeding seasons (from 2000 to 2005).A strong correlation was found between mean ATC activity and variations in interannual biomass for the anchovy population (R = 0.928; p < 0.01).During the study period the anchovy population collapsed, and a particularly low level of ATC activity in the mesozooplankton preceded this event 1 year earlier.Conversely, an increase in anchovy abundance in the year following the collapse was preceded by a return to substantially higher levels of ATC activity.We hypothesize that this relationship may be robust and generally applicable.We speculate on the environmental descriptors necessary to confirm this result, in view of its potential application to the monitoring of this valuable fish population in the Bay of Biscay.

Among metals, cadmium, a non-essential element, is an important pollutant that is released into aquatic environments. Due to its persistence and bioaccumulation, this metal has been shown to exert immunological effects on organisms. The objective of the present study was to investigate the in vitro effects of cadmium chloride using a haemocyte primary culture from the European abalone, Haliotis tuberculata. Most studies have maintained viable haemocytes in vitro for periods ranging from several hours to several days during acute exposures. Few investigations have reported the effects of metals using longer in vitro exposures, which are more realistic with regard to mimicking environmental conditions. In this study, we exposed abalone haemocytes to concentrations from 0.5 to 50,000μgL−1 of CdCl2 for 10 days. The effects of cadmium chloride were reflected in a significant decrease in the number of viable cells and morphological modifications in a concentration-dependent manner beginning at a concentration of 500μgL−1 as well as in some physiological processes, such as phagocytotic activity and the number of lysosome-positive cells. In contrast, phenoloxidase (PO) activity and reactive oxygen species (ROS) production were increased beginning at a concentration of 5μgL−1, which is consistent with environmental concentrations in polluted sites. For PO activity and ROS production, maximally 9-fold and 130% inductions, respectively, were recorded under the highest dose. These results thus indicate that cadmium chloride alters immune parameters of abalone haemocytes and that the long-term (10 days) primary culture system used here represents a suitable, sensitive in vitro model for assessing cytotoxic responses.

During spring 2005, satellite imagery revealed high sea surface chlorophyll a concentrations over the edge of a wide continental shelf in the Bay of Biscay (NE Atlantic). As a descriptor of biological productivity, mesozooplankton aspartate transcarbamylase specific activity was measured in situ during the bloom. Notably high values were detected in the bloom area relative to other parts of the study area.