scholarly journals Small burrowing amphipods cause major damage in a large kelp

2020 ◽  
Vol 287 (1926) ◽  
pp. 20200330
Author(s):  
Lars Gutow ◽  
Alistair G. B. Poore ◽  
Manuel A. Díaz Poblete ◽  
Vieia Villalobos ◽  
Martin Thiel
Keyword(s):  
Sea Urchins ◽  
Feeding Activity ◽  
Feeding Rates ◽  
Large Herbivores ◽  
Benthic Primary Production ◽  
Central Chile ◽  
Tissue Degeneration ◽  
Marine Macrophytes ◽  
Considerable Damage ◽  
Lessonia Berteroana

Large herbivores such as sea urchins and fish consume a high proportion of benthic primary production and frequently control the biomass of marine macrophytes. By contrast, small mesograzers, including gastropods and peracarid crustaceans, are abundant on seaweeds but have low per capita feeding rates and their impacts on marine macrophytes are difficult to predict. To quantify how mesograzers can affect macrophytes, we examined feeding damage by the herbivorous amphipods Sunamphitoe lessoniophila and Bircenna sp., which construct burrows in the stipes of subtidal individuals of the kelp Lessonia berteroana in northern-central Chile, southeast Pacific. Infested stipes showed a characteristic sequence of progressive tissue degeneration. The composition of the amphipod assemblages inside the burrows varied between the different stages of infestation of the burrows. Aggregations of grazers within burrows and microhabitat preference of the amphipods result in localized feeding, leading to stipe breakage and loss of substantial algal biomass. The estimated loss of biomass of single stipes varied between 1 and 77%. For the local kelp population, the amphipods caused an estimated loss of biomass of 24–44%. Consequently, small herbivores can cause considerable damage to large kelp species if their feeding activity is concentrated on structurally valuable algal tissue.

Impacts of water temperature on the physiology and behaviours of the sea urchins Heliocidaris crassispina and Mesocentrotus nudus that reflect their range extension and disappearance in the Oga Peninsula, northern Honshu, Japan

2020 ◽  
Author(s):  
Wenping Feng ◽  
Nobuyasu Nakabayashi ◽  
Eri Inomata ◽  
Masakazu N. Aoki ◽  
Yukio Agatsuma
Keyword(s):  
Low Temperature ◽  
Native Species ◽  
Feeding Rate ◽  
Sea Urchins ◽  
Temperature Limit ◽  
Feeding Rates ◽  
Righting Response ◽  
Mesocentrotus Nudus ◽  
Temperature Rate ◽  
High Or Low Temperature

Ocean warming has facilitated the extension of Heliocidaris crassispina to Oga Peninsula, Japan, where the native species Mesocentrotus nudus has disappeared. To verify the temperature impacts on the physiology and behaviour of the two species, we reared small sea urchins at the increasing/decreasing temperature rate of 2.5°C week-1. The righting response, lantern reflex, gonad and gut carbon (C) and nitrogen (N) contents, and feeding rate were investigated. The high and low temperature limits of H. crassispina were 33.3°C and 3.9°C, respectively, which were higher than those of M. nudus. The optimal temperature ranges for behaviour and feeding in H. crassispina were 10.3–31.0°C and 10.3–33.4°C, respectively, which were higher than those in M. nudus. Feeding rates decreased significantly in both species when the temperature approached the high or low temperature limit, but the gut C and N contents of were not greatly affected. At 26–31°C, the feeding rate significantly decreased in M. nudus but not in H. crassispina, which may explain the replacement of M. nudus by H. crassispina in the Oga Peninsula.

scholarly journals Seasonal dynamics of megafauna on the deep West Antarctic Peninsula shelf in response to variable phytodetrital influx

2014 ◽  
Vol 1 (3) ◽  
pp. 140294 ◽  
Author(s):  
P. Y. G. Sumida ◽  
C. R. Smith ◽  
A. F. Bernardino ◽  
P. S. Polito ◽  
D. R. Vieira
Keyword(s):  
Antarctic Peninsula ◽  
Feeding Activity ◽  
Community Response ◽  
Sediment Surface ◽  
Feeding Rates ◽  
Surface Deposit ◽  
Food Material ◽  
Important Species ◽  
West Antarctic ◽  
West Antarctic Peninsula

The deep West Antarctic Peninsula (WAP) shelf is characterized by intense deposition of phytodetritus during spring/summer months, while very little food material reaches the seafloor during winter. The response of the shelf benthic megafauna to this highly variable food supply is still poorly understood. In order to characterize the deposition of phytodetritus and the megabenthic community response, we deployed a seafloor time-lapse camera at approximately 590 m depth on the mid WAP shelf west of Anvers Island for 15 months. Seafloor photographs were taken at intervals of 12 or 24 h nearly continuously from 9 December 1999 (austral winter) to 20 March 2001 (summer) and analysed for phytodetritus deposition and megafaunal dynamics. Seafloor images indicated a marked seasonal arrival of greenish phytodetritus, with large interannual and seasonal variability in the coverage of depositing phytodetrital particles. The surface-deposit-feeding elasipod holothurians Protelpidia murrayi and Peniagone vignoni dominated the epibenthic megafauna throughout the year, frequently constituting more than 80% of the megafaunal abundance, attaining total densities of up to 2.4 individuals m −2 . Elasipod abundances were significantly higher in summer than winter. During summer periods of high phytodetrital flux, Pr. murrayi produced faecal casts at higher rates, indicating intensified population-level feeding activity. In March–June 2000, faecal casts lasted longest, suggesting lower horizontal bioturbation activity during autumn–winter. Our data indicate that the Pr. murrayi population increases its feeding rates in response to increasing amounts and/or lability of organic matter on the sediment surface. Assuming that this species feeds on the top millimetre of the sediment, we estimate that, during periods of high phytodetrital flux, the Pr. murrayi population reworks one square metre of sediment surface in approximately 287 days. We suggest that Pr. murrayi is an important species for organic-carbon recycling on the deep WAP shelf, controlling the availability of deposited labile phytodetritus to the broader shelf benthic community.

scholarly journals Abundancia y estructura poblacional de dos recursos pesqueros bentónicos fuera y dentro del área de una concesión marítima portuaria en Caldera, Región de Atacama, Chile

2019 ◽  
Vol 54 (2) ◽  
pp. 232
Author(s):  
JM Alonso Vega ◽  
Marcelo Valdebenito ◽  
Luis Caillaux ◽  
Jorge Bravo
Keyword(s):  
Protected Area ◽  
Reference Site ◽  
Marine Protected Area ◽  
Size Structure ◽  
Sea Urchins ◽  
The Future ◽  
Management Plans ◽  
Benthic Resources ◽  
Loxechinus Albus ◽  
Lessonia Berteroana

This study compares density and size structure of kelp Lessonia berteroana and sea urchins Loxechinus albus inside and outside a port concession area in Caldera. Greater abundance and larger adult individuals in populations of both benthic resources in this zone preliminarily indicates that this might be replicating a marine protected area. In the future, this port concession could contribute to the conservation of benthic resources as a reference site, without access to fisheries, useful for validating or implementing measures and actions in management plans or other instruments to support conservation.

Effects of ocean acidification on algae growth and feeding rates of juvenile sea urchins

2018 ◽  
Vol 140 ◽  
pp. 382-389 ◽  
Author(s):  
Adriana Rodríguez ◽  
Sabrina Clemente ◽  
Alberto Brito ◽  
José Carlos Hernández
Keyword(s):  
Ocean Acidification ◽  
Sea Urchins ◽  
Feeding Rates ◽  
Algae Growth

Seaweeds, Sea Urchins, and Lobsters: A Reappraisal

1985 ◽  
Vol 42 (12) ◽  
pp. 2061-2072 ◽  
Author(s):  
Robert J. Miller
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Stomach Contents ◽  
Homarus Americanus ◽  
Strongylocentrotus Droebachiensis ◽  
Sea Otter ◽  
Feeding Rates ◽  
Growth And Survival ◽  
Definition Of ◽  
Urchin Grazing

A popular hypothesis, that on the south coast of Nova Scotia the green sea urchin (Strongylocentrotus droebachiensis) has been released from control by predators, is critically reviewed. Predator control is given the functional definition of limiting sea urchin grazing sufficient to permit abundant growth of seaweed. Of the predators identified, the American lobster (Homarus americanus) is the least likely to have been important in sea urchin control in recent decades. Feeding rates, stomach contents, and field biomass are available for this species. A smaller amount of data available for the rock crab (Cancer irroratus) and benthic feeding fish points to the conclusion that they likewise cannot control urchin populations. Among other temperate sea urchin species the case is strongest for sea otter control of Strongylocentrotus sp. in some areas of the west coast of North America. The formation of sea urchin grazing fronts, a usual step in the destruction of seaweed beds, has been explained as a behavioral response to predators. This may in fact be merely a response to the location of food. Evidence for suspected enhancement of lobster production by seaweeds is equivocal, and comparative field data collected in and out of seaweed beds (e.g. lobster abundance, food, growth, and survival) have not been published.

scholarly journals Effects of dead conspecifics, hunger states, and seasons on the foraging behavior of the purple urchin Heliocidaris crassispina

2020 ◽  
Author(s):  
Dominic Franco C. Belleza ◽  
Yuuki Kawabata ◽  
Tatsuki Toda ◽  
Gregory N. Nishihara
Keyword(s):  
Foraging Behavior ◽  
Field Experiments ◽  
Prey Species ◽  
Sea Urchins ◽  
Time Lapse ◽  
Aquatic Environments ◽  
Feeding Rates ◽  
Avoidance Behaviors ◽  
Time Lapse Photography

ABSTRACTTrophic cascades exerts a powerful effect between predator and prey relationships in an ecosystem. In aquatic environments, the signals associated with predators and predation are used by prey as a cue to avoid encountering predators when foraging for food. These cues are powerful enough to control prey populations and indirectly protect primary producers. We evaluated the effects of cues associated with predation on the purple urchin, Heliocidaris crassispina and examined effects of hunger state and season using time-lapse photography, we conducted a series of manipulative and in situ behavior experiments to determine foraging behavior patterns which demonstrate behavior modification. The results suggest that starved urchins were less sensitive to predation cues when compared to normally fed urchins. Field experiments indicated that 70% of fed urchins fled when exposed to a predation cue (presence of a dead urchin), whereas all starved urchins remained regardless of the cue, supporting the results from the laboratory using the dead urchin and algae treatment cues. Sea urchin activity and feeding rates were lower in winter-spring than in summer-autumn. We suggest that hunger state has a large influence over the behavioral-response of sea urchins, while also being affected by season due to metabolic control. In general, starvation overrides predator avoidance behaviors and exposes prey species to higher risks of predation.

scholarly journals Population and feeding structure of Steindachnerina notonota Miranda-Ribeiro, 1937 (Actinopterygii, Characiformes, Curimatidae) in Taperoá II dam, semi-arid region of Paraíba, Brazil

2012 ◽  
Vol 23 (3) ◽  
pp. 233-244 ◽  
Author(s):  
Ana Karla Araujo Montenegro ◽  
Jane Enisa Ribeiro Torelli ◽  
Maria Cristina Crispim ◽  
Ana Maria Alves Medeiros
Keyword(s):  
Arid Region ◽  
Feeding Activity ◽  
Reproductive Period ◽  
Feeding Rates ◽  
Growth Type ◽  
Rainy Period ◽  
Feeding Structure ◽  
Semi Arid Region ◽  
Reproductive Activities ◽  
Semi Arid

AIM: The present study investigated population structure, weight-length relationships, sex ratio and associations between feeding activity and reproductive period, diet and alimentary regime of Steindachnerina notonota at Taperoá II dam, semi-arid region of Paraíba State. METHODS: The region has the lowest pluviometric rates of Brazil. Fishes were collected during six sampling periods (October and December/2005, and March, June, August and October of 2006) encompassing two dry periods, and one rainy period. Cast, seine and gill nets were used to collect the individuals. RESULTS: Throughout the study period 120 individuals were collected, with total length ranging between 2.2 and 10.7 cm and weight between 0.31 and 43.1 g. A recruitment period, identified due to a higher abundance of small individuals in the population, was observed in the beginning of the rainy period of 2006, lasting until the beginning of the dry season. S. notonota showed a negative allometric growth type, i.e., individuals 'elongate' during their development. A significantly higher proportion of females were observed throughout the study period. The relationship between feeding and reproductive activities were not significant, given that individuals showed high feeding rates regardless of the intensity of their reproductive activities. Although the diet of S. notonota comprised several items such as plant debris, eggs, organic matter, phytoplankton, zooplankton, Nematoda, Ostracada, Conchostraca, among others, the most important feeding item was detritus, suggesting a predominant detritivirous feeding habit. CONCLUSIONS: Biological aspects of S. notonota observed in the present study suggest that this species has potential to attain great population sizes, as consequence of both diet and feeding dynamics, as well as its reproductive characteristics and growth type.

scholarly journals Lethal and Sublethal Effects of Methyl Benzoate on the Predatory Bug Nesidiocoris tenuis

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 377
Author(s):  
Md Munir Mostafiz ◽  
Errol Hassan ◽  
Jae-Kyoung Shim ◽  
Kyeong-Yeoll Lee
Keyword(s):  
Sublethal Effects ◽  
Feeding Activity ◽  
Negative Control ◽  
Methyl Benzoate ◽  
Feeding Rates ◽  
Olfactory Responses ◽  
Nesidiocoris Tenuis ◽  
Rating Scheme ◽  
Plant Surfaces ◽  
Positive Controls

Benzoates (naturally occurring plant toxins) produce pesticidal effects on various pest insects and mites, but their effects on non-target insects are poorly understood. In this study, we evaluate the lethal and sublethal toxicity of methyl benzoate (MB) to adults of the generalist predatory bug Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae). To assess lethal effects, N. tenuis was exposed to plant surfaces treated with 0.25%, 0.5% and 1% MB, as well as negative and positive controls (water and the neonicotinoid acetamiprid, respectively). Exposure to 1% MB resulted in the highest corrected mortality of 17.8% and 13.3% under laboratory and greenhouse conditions, respectively. Thus, 1% MB can be classified as harmless to N. tenuis according to the International Organization for Biological Control rating scheme. At the sublethal level, MB exposure did not significantly affect the consumption of eggs of the whitefly Bemisia tabaci by N. tenuis relative to negative control feeding rates. In contrast, acetamiprid at the manufacturer’s recommended concentration reduced N. tenuis feeding activity by 45.4%. Furthermore, in a Y-tube olfactometer assay, there were no significant differences between the olfactory responses of N. tenuis to MB concentrations and the negative control (water). This study therefore suggests that MB could be used safely for pest control in combination with N. tenuis.

scholarly journals Reproductive biology of Paracentrotus lividus (Echinodermata: Echinoidea) in two contrasting habitats of northern Tunisia (south-east Mediterranean)

2007 ◽  
Vol 87 (3) ◽  
pp. 763-767 ◽  
Author(s):  
Fériel Sellem ◽  
Monique Guillou
Keyword(s):  
Sea Urchin ◽  
Reproductive Strategies ◽  
Sea Urchins ◽  
Feeding Activity ◽  
Paracentrotus Lividus ◽  
Mature Stage ◽  
Breeding Period ◽  
Northern Tunisia ◽  
Sheltered Site ◽  
Contrasting Habitats

The reproductive strategies of the sea urchin, Paracentrotus lividus, were studied in the Bay of Tunis. Samples were collected monthly, from September 1993 to August 1995, in two sites which differ in their marine vegetation and their exposure to wave action. Histological examination demonstrated a cycle of gametogenesis with six reproductive stages and a main breeding period occurring between April and June. Gonad indices varied between sites and years, the sheltered site presenting a higher investment in reproduction.This difference was essentially induced by the largest sea urchins (above 40 mm in diameter). Repletion indices showed a clear pattern without difference between sites and years. The sea urchin increase in feeding activity was controlled by the need to allocate nutrient to the gonad during the mature stage. But the gonad investment was not correlated with the intensity of food intake. Hydrodynamic conditions might play a key role in diverting energy to the maintenance in an exposed environment at the expense of reproduction.

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