Lophius Piscatorius Research Articles

APPLICATION OF QUALITY INDEX METHOD (QIM) SCHEME IN SHELFLIFE STUDY OF ANGLERFISH (Lophius piscatorius)

The aim was to evaluate a Quality Index Method (QIM) scheme for fresh Anglerfish (Lophius piscatorius). Anglerfish were stored at 0±2 °C on ice up to 9 days. Total Mesophilic Counts (TMC), Total Psychrophilic Counts (TPC) and counts of Specific Spoilage Organisms (SSOs) were done. An high correlation between the Quality Index (QI) and storage time on ice and between the Quality Index (QI) and H2S-producing bacteria counts was found. The remaining storage time could be estimated with accuracy of ±1.5 days when the Anglerfish were evaluated with QIM.

Test of 300 and 600 mm netting in the forward sections of a Scottish whitefish trawl

Comparative fishing trials investigated the effect of increasing the mesh size in the forward sections of a trawl from 120 and 160 mm to (i) 300 mm and (ii) 600 mm on the catches in the Shetland mixed whitefish fishery. The 300 and 600 mm trawls respectively caught an estimated 49 and 75% fewer Atlantic cod ( Gadus morhua), 79 and 93% fewer megrim ( Lepidorhombus whiffiagonis), 36 and 68% fewer ling ( Molva molva), and 28 and 53% fewer hake ( Merluccius merluccius) than the control trawl at all lengths. The 300 mm trawl caught ∼40% more haddock ( Melanogrammus aeglefinus) than the 600 mm and control trawls which had similar catch rates. The catch rates for monkfish ( Lophius piscatorius) were length dependent and the 300 mm trawl caught ∼50% fewer monkfish at 30 cm with no significant difference > 76 cm. The 600 mm trawl caught ∼90% fewer monkfish at 30 cm with no significant difference > 83 cm. Both the 300 mm and 600 mm trawls caught significantly fewer saithe ( Pollachius virens) above 53 cm.

Preservative effect of an organic acid‐icing system on chilled fish lipids

AbstractThis study provides a first approach concerning a novel chilling strategy, which employs a mixture of different preservative organic acids (ascorbic, citric and lactic) in the icing medium. Thus, ice prepared from water including two different concentrations of a commercial acid mixture‐formula (800 and 400 ppm; C‐800 and C‐400 conditions, respectively) were applied as icing system to three important commercial fish lean species (hake, Merluccius merluccius; megrim, Lepidorhombus whiffiagonis; angler, Lophius piscatorius). Lipid oxidation (peroxide value; thiobarbituric acid index; fluorescent compound formation) and hydrolysis (free fatty acid formation) were evaluated throughout the chilling time (up to 12–15 days) and compared to results obtained in fish kept under traditional ice prepared only from water (C‐0 condition); a complementary sensory evaluation was carried out. As a result of employing the C‐800 icing condition, a partial inhibition of lipid oxidation and hydrolysis development was obtained that was accompanied by a shelf life enhancement in all cases. Further research taking into account the complementary action of the present organic acids is envisaged. According to the lipid damage analysis, lipid hydrolysis was a more relevant event than lipid oxidation in all fish species tested.

Species selectivity in the Eastern Mediterranean demersal trawl fishery using grids to reduce non-target species

Summary Scientific studies have been conducted on size selectivity of trawls with grids in the Mediterranean; however, none has focused on species selectivity. The aim of the present study was to analyze the value of sorting grids with 20 mm bar spacing for species separation, in a demersal trawl fishery mainly targeting deep water rose shrimp (Parapenaeus longirostris) in the Eastern Mediterranean. Fishing trials were carried out 17–24 August 2008 onboard the commercial trawler ‘Hapuloglu’, using a modified bottom trawl net. The separation rate for silver scabbard fish (Lepidopus caudatus) was highest among all species with 98% by weight and 97% by number in 44 mm diamond (44D) and 40 mm square mesh (40S) codends, respectively. The exclusion of European hake (Merluccius merluccius) by the grid shows differences between 85 and 93%, in weight and 64 and 83% in number for codends of 44D and 40S, respectively. Excluding the ratio for greater forkbeard (Phycis blennoides), the angler fish (Lophius piscatorius) and broadtail short fin squid (Illex coindetii) varied between 93 and 97% in weight, and 81 and 86% in number in both codends. Losses of legal sized rose shrimp were determined as 23 and 25% in 44D and 40S, respectively. The results obtained in the present study demonstrate that substantial separation of fish and shrimp can be achieved in this Mediterranean demersal trawl fishery. However, further developments should be explored; for this purpose the behaviour of species has to be studied in relation to trawl and grid design and where commercial consequences of changes in gear technology need to be considered.

Influence of Host Biological Features on Macroparasites of the Two European Anglerfish Species, Lophius piscatorius and Lophius budegassa, off North and Northwest Spain

Two anglerfish species, Lophius piscatorius and Lophius budegassa, caught off the north and northwest coast of Spain in 2007, were examined for parasite infections. Four parasite taxa were chosen for study, i.e., Anisakis larvae Type I (sensu Berland, 1961), Hysterothylacium rigidum (Nematoda), Spraguea lophii (Microsporidia), and Chondracanthus lophii (Copepoda). Prevalence, intensity, and abundance were determined and related to host size and sex. The abundance of Anisakis larvae Type I significantly increased with size in both anglerfish species, and C. lophii was also more abundant in larger L. piscatorius specimens. The abundance of H. rigidum and the prevalence of S. lophii were unrelated to host size. The infestation with the parasites studied was not affected by host sex.

Transfer of fishing effort between areas and fishery units in Spanish fisheries as side effects of the prestige oil spill management measures

This paper shows how post-oil spill management measures can affect the general pattern of fishing effort exerted on two particular species of great commercial value in northern Spanish fisheries: anglerfish ( Lophius piscatorius and Lophius budegassa) and mackerel ( Scomber scombrus). Data time series of catches and fishing efforts were analysed corresponding to the area and time period affected by the oil spill fishing restrictions (December 2002–June 2003) and similar previous and post-spill periods. This was done to detect shifts that could be due to either the oil spill per se or the management measures taken to minimise pollution effects. Then, analyses and simulations with Arcview GIS module FAST (Fishing Activity Simulation Tool v. 1.1) were carried out with the aim of studying the fishing effort spatial distribution. Changes were observed in the Catch Per Unit Effort (CPUE) of anglerfish and mackerel by area or fishery unit. Results show a spatial displacement of fishing effort to other fishing areas in the case of anglerfish, and the transfer of fishing effort between different fishery units in the case of mackerel. Although both effects were caused primarily by the management measures in force after the oil spill, they are considered side or collateral effects. The management measures that have to be taken after any disaster should also consider these kinds of ancillary effects as well as evaluating the likely positive or negative impact of these side effects.

Phase transition in recruitment and distribution of monkfish (Lophius piscatorius) in Icelandic waters

The abundance and distribution of monkfish (Lophius piscatorius) at Iceland have increased rapidly in the last decade, concurrent with rising seawater temperatures and salinity. These environmental changes seem to have improved the reproductive success of the monkfish stock, and since 1998 large cohorts have recruited almost annually, in great contrast to at least 15 years prior to that. The study indicates that the transition in recruitment could be mediated by the direct effects of expanded nursery and feeding habitat through elevated temperatures. Other factors are likely to be involved, such as a more favourable egg and larval drift resulting from a changed inflow of surface water from spawning to nursery areas. A proportion of the monkfish stock in Icelandic waters may originate from distant areas, either by means of larval drift or active migration of larger fish.

Using existing industrial remotely operated vehicles for deep‐sea science

Since the mid‐18th century scientists have been using existing industrial technology for scientific investigation in remote places. This approach, pioneered by Linnaeus and his ‘Apostles’, is being used today to access deep‐water environments using remotely operated vehicles (ROVs) in collaboration with the offshore hydrocarbon industry, particularly through the Scientific and Environmental Remotely operated vehicle Partnership using Existing Industrial Technology (SERPENT) project. Industrial ROVs are well suited for scientific investigation with high quality imaging systems as standard. These have already been used to provide associated ecological information to taxonomic specimens and to describe feeding behaviours of monkfish (Lophius piscatorius) and a galatheid (Munida sarsi). In addition, work‐class vehicles have sufficient power and manipulation capacity to interact with the environment, permitting sample collection and experimental assessment of deep‐water ecological processes; examples are given of each of these investigations. The increased understanding of deep‐water systems is now being used by policy‐makers and industry to improve environmental management and monitoring procedures.

Distribution, abundance, and growth of anglerfish (Lophius piscatorius) on the Porcupine Bank (west of Ireland)

Abstract Velasco, F., Landa, J., Barrado, J., and Blanco, M. 2008. Distribution, abundance, and growth of anglerfish (Lophius piscatorius) on the Porcupine Bank (west of Ireland). – ICES Journal of Marine Science, 65: 1316–1325. This manuscript presents the first results on abundance and distribution of white anglerfish (Lophius piscatorius) from a series of groundfish surveys carried out on the Porcupine Bank. White anglerfish were caught in all trawlable areas, recruits and juveniles mainly from the shallower parts of the bank, around the central mound and closer to the Irish shelf. A strong cohort was manifest in 2001, and it could be tracked over time by age matrices obtained with illicia age–length keys (ALKs) collected during the surveys. However, a mismatch in the cohort analysis suggests that the growth pattern based on illicia underestimates around three of the younger age classes. Using an ALK estimated numerically from a faster growth model, this mismatch disappears, which seems to confirm faster growth. Recruits of the 0-group and adults of age 4 (with the faster growth: ca. ∼57–65 cm) dominated, whereas the intermediate age groups were scarce on the bank. These results and recent findings from tag-and-recapture experiments suggest that white anglerfish move to and from the Porcupine Bank, calling into question the stock boundaries currently accepted for the species in the North Atlantic.

Biological features of the Lophius piscatorius catch in Scottish waters

Abstract Laurenson, C. H., Dobby, H., McLay, H. A., and Leslie, B. 2008. Biological features of the Lophius piscatorius catch in Scottish waters. – ICES Journal of Marine Science, 65: 1281–1290. Here, data on 50 265 Lophius piscatorius sampled between 1998 and 2006 on board commercial fishing vessels during observer trips and chartered surveys at Shetland, west of Scotland, and Rockall are analysed. In each area, length differed significantly with depth (p < 0.001), there was an increase in modal size with increasing depth down to 450 m, and large fish dominated hauls in deeper water. The sex ratio of all data combined was 0.88 females:1 male, but it varied by area, depth, and season, with males greatly outnumbering females in deep water west of Scotland during the first quarter of the year. The proportion at length that were female differed significantly with depth, and the highest proportions of mature fish were in deep water at Rockall and west of Scotland. L50% maturities, for all data combined, were 102.4 cm for females and 58.3 cm for males.

Analyzing the market position of fish species subject to the impact of long-term changes: a case study of French fisheries in the Bay of Biscay

Market position and its evolution were analysed in nine key fish and cephalopod species subject to long- term changes, using the Bay of Biscay fisheries as a case study. Although such long term changes have already been documented, and in some cases shown to be related to the impacts of fishing, changes in the physical environment, or both, relatively little work has been devoted to their potential consequences in economic terms. The nature and extent of these consequences was determined in the present study by looking at the composition of the affected fish production, and the status of different fish products on the markets. We propose a methodology to characterize market position for this set of nine species. The selected species represent a significant part of the gross turnover of French fishing fleets operating in the bay. These species were characterized in terms of their potential sensitivity to fishing and changes in environmental conditions due to global warming. We separated species potentially positively (Engraulis encrasicolus and Lophius budegassa) and negatively affected (Pollachius pollachius and Lophius piscatorius) by warming. Evolution of the value of production of the nine species was then depicted using analysis of macro-economic index (production and potential consumption) and price indices. This revealed the relatively high sensitivity of domestic production to the market crisis that occurred in France in the early 1990s, compared to imported and exported products. The relative position of individual species, with respect to the market and its evolution between 1990 and 2005, was analyzed by multi-factorial analysis. Results derived from the analysis clearly distinguish two groups of species, the first character- ized by higher prices (monkfish, Nephrops, sole, seabass) and the second by larger volumes available on the French market (pollack, hake, anchovy, sardine, cuttlefish). We conclude that a major part (69 to 87%) of the gross turnover associated with catches of these fish species in the Bay of Biscay remains potentially unaffected by long-term changes related to climate.

The Lophius budegassa component of monkfish catches in Scottish waters

Abstract Laurenson, C. H., Dobby, H., and McLay, H. A. 2008. The Lophius budegassa component of monkfish catches in Scottish waters. – ICES Journal of Marine Science, 65: 1346–1349. To date, research efforts on Lophius species in waters around Scotland (ICES Divisions IVa, VIa, and VIb) have focused almost exclusively on Lophius piscatorius. Here, the characteristics and distribution of the Lophius budegassa component of the catch are described using data collected by observers during commercial fishing trips and scientific surveys on chartered commercial fishing vessels between 1998 and 2006. At Rockall Bank (VIb), L. budegassa were rare, just 0.1% of the catch of Lophius spp., whereas west of Scotland (VIa) and around the Shetland Islands (IVa), they made up 18 and 2% of catches, respectively, with greatest prevalence towards the shelf edge. Fish length ranged from 16 to 89 cm with a modal length at 40 cm. Greater proportions of large individuals were recorded around the Shetland Islands than in other parts of the study area. Overall, the sex ratio was 1:1, and lengths at 50% maturity were estimated to be 70.4 cm for females and 49.4 cm for males.

Application of dynamic factor analysis in the assessment of Iberian anglerfish stocks

Abstract Azevedo, M., Duarte, R., Cardador, F., Sousa, P., Fariña, C., Sampedro, P., Landa, J., and Costas, G. 2008. Application of dynamic factor analysis in the assessment of Iberian anglerfish stocks. – ICES Journal of Marine Science, 65: 1362–1369. Dynamic factor analysis (DFA) was applied to six time-series of catch per unit effort data of the Iberian (ICES Divisions VIIIc and IXa) white anglerfish (Lophius piscatorius) and black anglerfish (L. budegassa). Results showed that grouping the abundance indices reflected the fleet's area of exploitation and fish size selection. Two common trends (CTs) were extracted for each species, capturing the main signal of abundance over time. The white anglerfish was assessed using these CTs as input to the biomass dynamic model currently used in the ICES assessment, to investigate whether the approach would reduce the uncertainty in parameter estimates and related quantities. Using the CTs, bias estimates are lower. The current perception of an overexploited stock is unchanged, but a much lower intrinsic rate of biomass increase was estimated, indicating that the biomass recovery might be much slower. A lower maximum sustainable yield, ∼3600 t, was obtained, and this is more consistent with the historical landings trajectory. The application of DFA to stock assessment of anglerfish, presented here for the first time, can be extended to age-based assessments.

Selectivity of a 50-mm diamond mesh knotless polyethylene codend for commercially important fish species in the Aegean Sea

Summary This research investigated effects of changing the diamond mesh size on codend selectivity in Mediterranean fisheries. The selectivity of a typical 50-mm diamond knotless polyethylene (PE) codend used in the Turkish fishery in the Aegean Sea was measured for commercially important species, in particular hake (Merluccius merluccius), horse mackerel (Trachurus trachurus), anglerfish (Lophius piscatorius) and John Dory (Zeus faber). Fishing trials were carried out on the commercial trawler ‘Hapuloglu’ between 9 and 12 December 2006 using a modified trawl net. Selectivity data were collected by the covered codend method and analysed by means of a logistic equation (Maximum Likelihood Method). The mean selectivity curve was estimated from individual hauls, taking between-haul variations into account. Mean mesh size of the codend was 49.4 mm as measured by digital calliper. Mean values for 50% retention length of hake and horse mackerel were estimated to be 11.4 and 15.6 cm total length; corresponding selection ranges were 4.1 and 5.5 cm respectively. The 50-mm diamond mesh codend showed adequate selectivity compared to the minimum landing size (MLS) for horse mackerel, while for hake it selected specimens in a size range far lower than the MLS. No selectivity values could be determined for anglerfish or John Dory. To design a more selective codend for the Turkish demersal trawl fishery, not only mesh size regulations but also other codend characteristics and netting material properties must be urgently considered.

Growth of white anglerfish (Lophius piscatorius) tagged in the Northeast Atlantic, and a review of age studies on anglerfish

Abstract Landa, J., Duarte, R., and Quincoces, I. 2008. Growth of white anglerfish (Lophius piscatorius) tagged in the Northeast Atlantic, and a review of age studies on anglerfish. – ICES Journal of Marine Science, 65: 72–80. Growth of white anglerfish was estimated from the results of a tagging study in south European waters. In all, 1326 fish, caught by bottom trawl and gillnet commercial vessels and on trawl surveys, were tagged from 1995 to 2004; 50 were recovered, and a growth rate of 13.6 cm year−1 was estimated from the four fish at liberty long enough to allow extrapolation of the growth rate to an annual period. Growth patterns were reviewed based on available studies of growth verification of white anglerfish in Atlantic waters, including another tag-recapture study, length-frequency of catches, and microstructure analysis of hard parts. The growth rate estimated from these studies showed many similarities, and an overall growth pattern was estimated: growth rate = 18.24e–0.015length. A von Bertalanffy growth curve fitted to all data yielded the parameter values L∞ = 140 cm and k = 0.11. This growth rate is faster than estimated recently using illicia for age estimation, but similar to that found in the first studies that used illicia and sectioned otoliths. Current estimates of growth based on illicia, which are used in assessing the northern European stock of white anglerfish, seem to be underestimated.

The status of Lecithochirium grandiporum (Rudolphi, 1819) (Digenea: Hemiuridae), a rarely reported and poorly known species from the Mediterranean moray eel Muraena helena L. in the Western Mediterranean

A redescription of the poorly known Lecithochirium grandiporum (Rudolphi, 1819) is given based on numerous specimens collected from the stomach of the moray eel Muraena helena in the waters off the Scandola Natural Reserve, Corsica, in the Western Mediterranean. This species, abundant in all specimens of the moray eel studied in this region, is shown to be a valid species and not stunted specimens of L. fusiforme Lühe, 1901, a common parasite of the conger eel Conger conger which has developed in the wrong host. Comparative morphological and metrical studies, based on numerous specimens from the same geographical area, show that L. grandiporum from M. helena and L. fusiforme from C. conger and Lophius piscatorius represent one and the same species, the latter becoming a junior synonym of L. grandiporum. In addition, a list of the digenean species collected from each of these three fish species from off the Scandola Natural Reserve is given, showing the similarities between their digenean fauna.

Enhanced quality and safety during on-board chilled storage of fish species captured in the Grand Sole North Atlantic fishing bank

The Grand Sole North Atlantic fishing bank is exploited by several European countries, although time lapsed between catch and destiny arrival can attain 15 days. In the present work, the use of slurry ice (SI) system was investigated for the on-board storage of chilled fish and carried out in parallel to traditional flake icing (FI). Three species (hake, Merluccius merluccius; angler, Lophius piscatorius; ray, Raja clavata) widely present in the mentioned bank were studied. A lower ( p < 0.05) microbial (aerobes, psychrotrophes, proteolytics) development was observed in fishes subjected to SI system than in their counterpart specimens stored under FI. This correlated with lower ( p < 0.05) productions of trimethylamine (hake and angler) and total volatile bases (ray) and extended shelf-life for fish species kept under SI conditions. In summary, on-board employment of SI can provide higher quality and safety products to consumer and allow increased commercial values while unloading and sale.

The occurrence of the Japanese species Dinosoma lophiomi Toman, 1973 (Digenea: Hemiuridae) in Lophius piscatorius (Teleostei) from the western Mediterranean

Hemiurid worms from the stomach of the angler Lophius piscatorius off Corsica are described and considered to belong to a Japanese species, Dinosoma lophiomi Toman, 1973, which was originally described from an Indo-Pacific lophiid host. The apparent disjunctive distribution of this species and apparent differences in the terminal genitalia between the European and Japanese specimens are discussed. This is the first record of Dinosoma Manter, 1934 from the Mediterranean Sea. The validity of diagnostic features of Adinosoma Manter, 1947 is commented upon, and lists of records of species of Dinosoma and digeneans from L. piscatorius in the Western Mediterranean are included.

Prosorhynchoides gracilescens (Rudolphi, 1819) (Digenea: Bucephalidae) from Lophius piscatorius L. is a species complex: a redescription of this species (sensu stricto) from the western Mediterranean and the description of P. borealis n. sp. from the northern North-East Atlantic

The bucephalid digenean Prosorhynchoides gracilescens (Rudolphi, 1819) is a common intestinal parasite of the angler fish Lophius piscatorius in European marine waters. Detailed studies of new material collected off the coasts of both Marseilles and Corsica in the western Mediterranean, and comparison with museum material from the northern North-East Atlantic, indicated that the accepted concept of this species comprises two distinct taxa. The Mediterranean form occurs in relatively small numbers and has small eggs, a large rhynchus and a vitelline distribution that finishes well short of the rhynchus, whereas the NE Atlantic form, which comprises the majority of records, occurs often in large numbers, has larger eggs, a relatively smaller rhynchus and a vitelline distribution that tends to reach the rhynchus. Since the type-material is from the Mediterranean and resembles the Mediterranean form, there was little option but to consider the latter as P. gracilescens (sensu stricto) and to describe the NE Atlantic form as a new species, for which the name P. borealis n. sp. is coined to reflect its northerly distribution. Both species are described and figured in detail, and a table and illustration of the diagnostic features are presented. In addition, some discussion is included on the distribution of these two species and whether P. gracilescens (s. str.) might be a relict species, and on non-European records of P. gracilescens (sensu lato).

A note on the development of the embryos of anglerfish Lophius piscatorius

Embryo development over a 5 day period are shown and described from a rare find of anglerfish Lophius piscatorius spawn that was obtained at the Shetland Islands, U.K. The stage of development shown is earlier than that previously available for the species.