Feeding of the spider crab Maja squinado in rocky subtidal areas of the Ría de Arousa (north-west Spain)

The diet of the spider crab, Maja squinado, was studied in the rocky subtidal areas of the Ría de Arousa (Galicia, north-west Spain), by analysing the gut contents of crabs caught in the summer and winter of 1992. The highly diverse diet was made up primarily of macroalgae and benthic invertebrates that were either sessile or had little mobility. The most important prey were the seaweeds Laminariaceae (43% of the frequency of occurrence and 15% of the food dry weight), Corallina spp. (38% and 3%), molluscs [the chiton Acanthochitona crinitus (15% and 1%), the gastropods Bittium sp. (30% and 2%), Trochiidae and others and the bivalve Mytilus sp. (32% and 12%)], echinoderms [the holothurian Aslia lefevrei (32% and 18%) and the echinoid Paracentrotus lividus (16% and 7%)] and solitary ascidians (18% and 6%). The variability in diet composition was determined by the season (Laminariaceae, Corallina spp., P. lividus, Mytilus sp., gastropods and chitons appeared in greater frequency in winter, while the solitary ascidians and A. lefevrei were consumed to a greater extent in summer) in addition to sexual maturity (prey such as Bittium sp. or Trochiidae were more common in juveniles). Moreover, the changes in the food consumption rate were linked primarily to the moult stage. Feeding activity plummeted during the phases immediately preceding and following ecdysis (stages D0–D3–4 and A), and the diet was less diverse during these phases. No feeding differences were found that could be linked to sex. The composition of the diet of Maja squinado appears to be determined by the seasonal abundance of the different prey in subtidal rocky areas and by their availability (depending on their behavioural and anatomical characteristics, mainly mobility and the presence of hard external structures). Moreover, life history factors have little importance in the variability of the diet composition and only the moult cycle has a considerable effect on feeding rate.

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Feeding activity and diet composition of round goby (Neogobius melanostomus, Pallas 1814) in the coastal waters of SE Baltic Sea

Oceanological and Hydrobiological Studies ◽

10.1515/ohs-2015-0048 ◽

2015 ◽

Vol 44 (4) ◽

Cited By ~ 7

Author(s):

Artūras Skabeikis ◽

Jūratė Lesutienė

Keyword(s):

Baltic Sea ◽

Coastal Waters ◽

Diet Composition ◽

Feeding Activity ◽

Macoma Balthica ◽

Round Goby ◽

Benthic Fauna ◽

Neogobius Melanostomus ◽

The Body ◽

Gut Contents

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.

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Diet Composition and Seasonal Fluctuations in the Feeding Habit of Snow Barbel (Schizothorax plagiostomus) in River Indus, Pakistan

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.82439 ◽

2018 ◽

Vol 46 (1) ◽

pp. 8

Author(s):

Muhammad Qayash Khan ◽

Muhammad Zubair Anjum ◽

Shamim Akhter ◽

Irfan Khattak ◽

Abid Ali

Keyword(s):

Diet Composition ◽

Feeding Activity ◽

Fish Fauna ◽

Feeding Habit ◽

Gut Contents ◽

Catch Per Unit Effort ◽

Food Items ◽

Unit Effort ◽

Significant Difference ◽

River Indus

Background:Schizothorax plagiostomus is widely distributed in river Indus and is most important food fish in Pakistan. The feeding habit of fish is directly related to the size of fish, its metabolic rate and environmental temperature. The accurate description of fish diet and feeding habit is a very important aspect in fisheries management for the purpose of species conservation, breeding and culture. The present work was aimed to investigate the specie abundance, the diet composition and seasonal variations in the feeding habit of Snow barbell Schizothorax plagiostomus.Materials, Methods & Results: A total of 1799 fish specimens were caught at the confluence of six tributaries along river Indus at Indus Kohistan, northeastern Pakistan. The fish were collected by 5-panels of gill net during first week of each month. The site specific Catch Per Unit Effort (CPUE) and season specific CPUE of fish fauna were assessed. For the gut content analysis 240 samples (99 male and 141 females) of S. plagiostomus were selected on monthly basis. Frequency of occurrence method and volumetric method were applied to record the different food items in the gut of S. plagiostomus. The physico-chemical parameters, NO3 concentration and dissolved Co2 of water from different localities of river Indus were recorded month wise by Hach sensION 156 meter, Horiba LAQUA Nitrate Meter and EA80 meter respectively. Significant difference was observed in water temperature during the four seasons. Except alkalinity no other water parameter showed significant variation across different localities. The results showed that highest Mean CPUE was observed for Darel Stream (0.55) and lowest for Jalkot stream (0.26). Peak abundance of fish was recorded in the month of November with a mean catch of 44.50, mean CPUE of 0.74 and mean Kruskal-Wallis rank value of 63.25. Spirogyra and Ulothrix occurred as maximum food items in the gut of S. plagiostomus during summer while their minimum amount occurred during autumn. According to the ranking index spirogyra and ulothrix ranked higher with significant difference in comparison to other food items. The results showed that S. plagiostomus is phytophagous in its feeding habit, which consumed mainly algae attached to stones and pebbles during the whole year. However, the presence of some secondary items such as animal matter, detritus, sand and mud might be due to the distinct availabilities of food along the seasons. The highest feeding activity of S. plagiostomus was recorded during summer while the lowest one occurred during autumn, spring and winter. Discussion: Catch per unit effort (CPUE) is an indirect measure of the abundance of a target species. It is used as an index of stock abundance in fisheries and conservation biology. During the study low fish fauna was found in River Indus as reported previously. Majority of the fish occurred in snow fed river tributaries in the study area as these tributaries are comparatively less turbulent. Previous studies have also recorded that Schizothoracine generally prefer clean waters. The present findings of gut contents analysis showed clearly that S. plagiostomus is a phytophagous fish which scrap and consumed spirogyra and ulothrix attached to stones and pebbles. Earlier it was reported that mouth of S. plagiostomusis is inferior, wide, with deep lower jaw having keratinized cutting edge and the lower lip is folded and expanded with numerous papillae making it best suited for scrapping algae attached to stones and pebbles. The highest feeding activity was observed during warmer months as compared to cold months. S. plagiostomus spawn twice in a year in autumn and in spring. The highest feeding activity of S. plagiostomus seems to be link with a reflex of recovery strategy due to physiological process of gonadal development.

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Moult cycle and growth of Maja squinado (Decapoda: Majidae) in coastal habitats of Galicia, north-west Spain

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315403008208h ◽

2003 ◽

Vol 83 (5) ◽

pp. 995-1005 ◽

Cited By ~ 19

Author(s):

María-Paz Sampedro ◽

Eduardo González-Gurriarán ◽

Juan Freire

Keyword(s):

Growth Rates ◽

Microscopic Observation ◽

Moult Cycle ◽

Spider Crab ◽

Length Frequency Distribution ◽

Length Frequency ◽

North West ◽

Abdominal Vein ◽

Increment Rate ◽

Males And Females

Over the course of the moult cycle of Maja squinado, the spider crab changes in the hardness and colour of the carapace were assessed and used as methods to identify the intermoult stage in each individual. This intermoult staging was later verified by means of the microscopic observation of the maxilla. These staging techniques made it possible for the prompt identification of the principal intermoult stages—postmoult, intermoult and premoult. In 90% of the cases analysed, there was a correlation between the presence of an underlying carapace and a pink colour of the abdominal vein in crabs in advanced premoult stages.The seasonality of the moult was studied based on the number of specimens in the postmoult stage. There were two main moulting periods—the first occurring in April, and the second, longer period was between July and November. A hypothetical growth model was established and growth rates were determined by length–frequency distribution analyses. Three groups of juveniles and one group of adults were identified. The adults were only found among the population between July and October. In both males and females, the moult increment rate was lower in terminal moults (mean=22%) than in juvenile or prepubertal moults (mean=27%).

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Impact of Feeding Activity of Silver Carp on Plankton Removal from a High-Rate Pond Effluent

Water Quality Research Journal ◽

10.2166/wqrj.2005.022 ◽

2005 ◽

Vol 40 (2) ◽

pp. 191-201 ◽

Cited By ~ 2

Author(s):

Nadia Berday ◽

Driss Zaoui ◽

Abdeljaouad Lamrini ◽

Mustapha Abi

Keyword(s):

Feeding Activity ◽

Silver Carp ◽

Treatment Plant ◽

High Rate ◽

Fish Pond ◽

Gut Contents ◽

Hypophthalmichthys Molitrix ◽

Technology System ◽

Solids Concentration ◽

Plankton Communities

Abstract The effect of silver carp (Hypophthalmichthys molitrix Val.) feeding activity on the plankton communities in a high-rate pond technology system (HRPTS) effluent was investigated over a period of 100 days. The experiment was conducted at the experimental wastewater treatment plant of the Agronomic and Veterinary Medicine Institute (AVI) of Rabat, Morocco, using a HRPTS in a fish pond receiving the plant effluent. The effluent was highly dominated by phytoplankton (99.95%). Silver carp could survive and grow in the fish pond. Production was 37 kg with a very low mortality rate (12%). The high specific intestine weight (7%) and intake rates of biomass and phytoplankton by silver carp (616 g kg-1 of fish day-1 and 1.6 x 1011 cell kg-1 of fish day-1, respectively) demonstrated the importance of the feeding activity of the fish. Zooplankton intake rates were lower (2 x 107 bodies kg-1 of fish day-1). The high intestine index (3 to 4.3 for fish sizes of 14 to 22 cm) and the dominance of phytoplankton in the gut contents (99.95%) confirmed an omnivorous/ phytoplanctivorous diet. Silver carp were efficient in removing plankton from the HRPTS effluent. The net removal yields of biomass were 285 g m-3 day-1 and 322 g kg-1 of fish day-1, 7 x 1010 algal cells kg-1 of fish day-1 and 8.7 x 107 zooplankton bodies kg-1 of fish day-1, with net removal rates of 47, 64 and 62%, respectively. The total suspended solids concentration decreased from 211 in the inflow to 112 mg L-1 in the fish pond.

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Metabolism of the mussel Mytilus galloprovincialis from two origins in the Ría de Arousa (north-west Spain)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400002848 ◽

2000 ◽

Vol 80 (5) ◽

pp. 865-872 ◽

Cited By ~ 38

Author(s):

Jose M.F. Babarro ◽

María José Fernández-Reiriz ◽

Uxío Labarta

Keyword(s):

Oxygen Consumption ◽

Rocky Shore ◽

Mytilus Galloprovincialis ◽

Excretion Rate ◽

Ammonia Excretion ◽

Dry Weight ◽

North West ◽

Cultivation Period ◽

Seed Origin ◽

Ammonia Excretion Rate

Mussel seed Mytilus galloprovincialis (Bivalvia: Mytilidae) from two origins (rocky shore and collector ropes) was cultivated on a raft in the Ría de Arousa (north-west Spain), from seeding to thinning out, for 226 d (November 1995–July 1996) and two aspects of metabolism, oxygen consumption rate (VO2) and ammonia excretion rate (VNH4-N) were studied in situ.The model derived from multiple analysis of oxygen consumption accounted for 91.9% of the variance, based on dry weight of the mussels and the environmental factors quality of food (organic content) and mainly chlorophyll-a. Seed origin also showed significant influence. The seasonal pattern of the oxygen consumption can be attributed mainly to the variation of chlorophyll-a, which showed a higher range of values in the spring months.Origin of seed did not show a homogeneous effect on oxygen consumption throughout the cultivation period. Collector rope mussels showed higher oxygen consumption values at the beginning of the cultivation period and after the first 15 d, but the rocky shore mussels showed a higher oxygen consumption between days 22 and 110. Energy-conserving patterns and lower condition index at the onset of the experiment for rocky shore mussels could explain these initial differences.Multiple analysis on the variation of ammonia excretion rate provided a model that accounted for 72.6% of the variance based on dry weight of mussels, seed origin and the environmental parameters chlorophyll-a and total particulate matter. The rocky shore mussels showed a significantly higher excretion values for most of the cultivation period, although there was no constant tendency throughout. High excretion values were recorded between January and March, whilst for the rest of the cultivation period values were low.The O:N index was higher in collector rope mussels for most of the cultivation period, which may suggest a more favourable energy metabolism and/or a more appropriate nutritional state for these specimens.

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FEEDING AND REPRODUCTIVE ACTIVITY OF THE COPEPODS Drepanopus forcipatus AND Calanus australis DURING LATE SUMMER ON THE SOUTHERN PATAGONIAN SHELF (ARGENTINA, 47°-55°S)

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592014073406204 ◽

2014 ◽

Vol 62 (4) ◽

pp. 295-314 ◽

Cited By ~ 10

Author(s):

Julieta Carolina Antacli ◽

Marina E. Sabatini ◽

Ricardo I. Silva ◽

Daniel R. Hernández ◽

Andrés J. Jaureguizar ◽

...

Keyword(s):

Diet Composition ◽

Feeding Activity ◽

Food Pellet ◽

Late Summer ◽

Reproductive Activity ◽

Seasonal Temperature ◽

Patagonian Shelf ◽

Adult Females ◽

Female Reproductive Status ◽

Potential Food

Drepanopus forcipatus and Calanus australis are key planktonic copepods on the southern Patagonian shelf. Their feeding and reproductive patterns and population status were investigated during late summer, when environmental conditions may be critical. The presence of food in the gut and food-pellet length were recorded in adult females and the most abundant copepodite stages. Diet composition was also studied in adult females. Female reproductive status was evaluated by gonad staging. Despite generally low feeding conditions and decreasing seasonal temperature, both copepods fed to some degree. The most numerous copepodites and adult females of both species showed similarly low feeding activity. About half of the adult females of the two species and C5s of C. australis contained food in their guts, but the proportion of fed C4-females of D. forcipatus was much lower. All copepods were generally feeding at low or intermediate levels. Gonad stage distribution and population structure showed low but still ongoing reproduction in both species. Gut content findings suggest a preference for smaller nanoplanktonic particles, especially dinoflagellates by D. forcipatus, and for autotrophic prey, particularly large diatoms by C. australis. The feeding and reproduction patterns of the two copepods were likely influenced by the distributions of potential food resources and temperature.

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PENGARUH KONSENTRASI MINYAK KEMIRI SUNAN (Reutealis trisperma (Blanco) Airy Shaw) TERHADAP LARVA Crocidolomia binotalis Zell. (Lepidoptera; Pyralidae) HAMA PADA TANAMAN SAWI (Brassica juncea L.)

AGROSCRIPT Journal of Applied Agricultural Sciences ◽

10.36423/agroscript.v1i2.271 ◽

2020 ◽

Vol 1 (2) ◽

Author(s):

Yenny Muliani ◽

Erry Mustariani ◽

Rahmat Wahid Ramdyan

Keyword(s):

Feeding Activity ◽

Dry Weight ◽

Plant Diseases ◽

Hazelnut Oil ◽

Botanical Pesticide ◽

Crocidolomia Binotalis ◽

Randomized Design ◽

Lepidoptera Pyralidae ◽

The University ◽

And Control

ABSTRAKKemiri sunan (Reutealis trisperma (Blanco) Airy Shaw) dikenal sebagai tumbuhan yang berperan sebagai pestisida nabati yang belum banyak diketahui keampuhannya, sehingga perlu dilakukan pengujian untuk memperoleh informasi tentang keampuhan dari tumbuhan ini. Pengujian efektivitasnya dilakukan terhadap larva Crocidolomia binotalis Zell. penyebab kerusakan pada tanaman sawi. Percobaan dilaksanakan di Laboratorium Vertebrata, Departemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Padjadjaran, Jatinangor, berlangsung dari Maret sampai Mei 2019. Percobaan menggunakan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 5 ulangan. Perlakuan meliputi minyak kemiri sunan dengan konsentrasi 10%, 5%, 2.5%, 1.25% dan kontrol. Hasil penelitian menunjukkan minyak kemiri sunan berpengaruh terhadap larva Crocidolomia binotalis. Konsentrasi 10% dapat mengakibatkan mortalitas paling tinggi sebesar 100% pada 7 HSA. Selain toksik, minyak kemiri sunan juga dapat memperpanjang lama perkembangan larva, menghambat aktivitas makan (antifeedant), serta menurunkan berat kering larva dibandingkan dengan kontrol. Minyak kemiri sunan berpotensi sebagai alternatif pengendali hama yang ramah lingkungan karena dapat berperan sebagai pestisida nabatiKata kunci: Kemiri sunan, Crocidolomia binotalis, Pestisida nabatiABSTRACTReutealis trisperma (Blanco) Airy Shaw is know as a plant that acts as a vegetable pesticide that is not yet widely known for its efficacy, so testing is needed to obtain information about the efficacy of this plant. Effectiveness testing is carried out on Crocidolomia binotalis Zell. larvae causing damage to oil palm plants. The experiment was carried out in the vertebrate laboratory, the deparment of pest and plant diseases, the faculty of agriculture, the university Padjadjaran, taking place from March-May 2019. The experiment used the randomized design complete with 5 treatments and 5 replication. The treatments included oil Reutealis trisperma (Blanco) Airy Shaw with a concentration 10%, 5%, 2.5%, 1.25% and control. The result hazelnut oil affected the larva Crocidolomia binotalis Zell. 10% concentration can cause the highest mortality of 100% at 7 HAS. In addition to toxic, hazelnut oil prolong the development of larvae, inhibit feeding activity, and reduce the dry weight of larvae compared to controls. Hazelnut oil has potential as an alternative as an a alternative pest control that is environmentally friendly because it can act as a botanical pesticide.Keywords : Reutealis trisperma, Crocidolomia binotalis, Botanical pesticide

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Proceedings of the First International Snakehead Symposium

Proceedings of the First International Snakehead Symposium ◽

10.47886/9781934874585.ch6 ◽

2019 ◽

Keyword(s):

Management Practices ◽

Feeding Habits ◽

Feeding Activity ◽

Movement Patterns ◽

Diel Activity ◽

Gut Contents ◽

Random Forest Models ◽

Radio Transmitters ◽

Diurnal Species ◽

Tracking Period

Abstract.—Understanding the diel activity of a species can shed light on potential interactions with other species and inform management practices. To understand the diel activity of Northern Snakehead Channa argus, feeding habits and movement patterns were observed. Two hundred seventy-three Northern Snakehead were captured by boat electrofishing during May and June of 2007 and 2008. Their gut contents were extracted and preserved. The level of digestion of each prey item was estimated from fresh (1) to >50% digested (4) or empty (5). Random forest models were used to predict feeding activity based on time of day, tide level, date, water temperature, fish total length, and sex. Diel movement patterns were assessed by implanting Northern Snakehead with radio transmitters and monitoring them every 1.5 h for 24 h in both March and July 2007. Movement rates were compared between March and July and among four daily time periods. Independent variables accounted for only 6% of the variation in feeding activity; however, temporal feeding patterns were apparent. No fresh items were observed in guts between 12:30 and 7:30 am, and the proportion of empty stomachs increased at the end of May coinciding with the onset of spawning. Overall, fish moved greater distances during the July tracking period compared to March. Fish showed a greater propensity to move during daylight hours than at night during the March tracking period. A similar but nonsignificant (P > 0.05) pattern was observed in July. Movement and feeding data both indicated greater activity during daylight hours than at night, suggesting that Northern Snakehead is a diurnal species. Based on our preliminary findings, we hypothesize that a) diurnal species are more susceptible than nocturnal species to predation by Northern Snakehead and b) Northern Snakehead are more likely to compete for food with diurnal than nocturnal predators.

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