scholarly journals Influence of natural settlement cues on the metamorphosis of fiddler crab megalopae, Uca vocator (Decapoda: Ocypodidae)

2010 ◽  
Vol 82 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Darlan J.B. Simith ◽  
Karen Diele ◽  
Fernando A. Abrunhosa
Keyword(s):  
Development Time ◽  
Chemical Cues ◽  
Fiddler Crab ◽  
Mangrove Ecosystem ◽  
Benthic Habitats ◽  
Settlement Cues ◽  
Conspecific Adult ◽  
Juvenile Crab ◽  
Crab Stage ◽  
Induction Of Metamorphosis

Megalopae of many decapod crab species accelerate their development time to metamorphosis (TTM) when exposed to natural physical and/or chemical cues characteristic of the parental habitat. In the present study, the influence of natural settlement cues on the moulting rates and development TTM in megalopae of the fiddler crab Uca vocator was investigated. The effects of mud from different habitats (including well-preserved and degraded-polluted mangrove habitats) and conspecific adult 'odours' (seawater conditioned with crabs) on the induction of metamorphosis were compared with filtered pure seawater (control). 95 to 100% of the megalopae successfully metamorphosed to first juvenile crab stage in all treatments, including the control. However, the development TTM differed significantly among treatments. Settlement cues significantly shortened development, while moulting was delayed in their absence. The fact that megalopae responded to metamorphosis-stimulating cues originating from both adult and non-adult benthic habitats demonstrates that settlement in this species may occur in a wider range of habitats within the mangrove ecosystem, including impacted areas.

scholarly journals The role of adult fiddler crab environmental acoustic cues and chemical cues in stimulating molting of field-caught megalopae

2021 ◽  
Vol 537 ◽  
pp. 151516
Author(s):  
Emily E. Waddell ◽  
Wendy E.D. Piniak ◽  
Kathleen A. Reinsel ◽  
James M. Welch
Keyword(s):  
Chemical Cues ◽  
Fiddler Crab ◽  
Acoustic Cues

scholarly journals Booklet development based on research identification of fiddler crab (Uca spp.) diversity in mangrove ecosystem

2018 ◽  
Vol 4 (1) ◽  
pp. 61
Author(s):  
Ajizatunnisa Ajizatunnisa ◽  
Sri Wahyuni ◽  
Lud Waluyo ◽  
Fuad Jaya Miharja
Keyword(s):  
Local Community ◽  
Fiddler Crab ◽  
Research Result ◽  
Biology Education ◽  
Mangrove Ecosystem ◽  
Fiddler Crabs ◽  
Ecological Benefits ◽  
The University ◽  
Self Learning ◽  
Product Specifications

The purpose of this development study is to develop research-based booklet for the identification of fiddler crab (Uca spp.) diversity. Some people do not yet know the ecological benefits of fiddler crabs. This is apparent when some people take fiddler crabs to serve as decorative crabs. The product specifications expected in the development of this medium are booklets. Therefore, it takes a companion learning media that can lead the local community to implement self-learning in the form of booklet because their interest of reading is very less, especially when reading a book that is colorless and has a lot of words. Booklet that is packed with interesting and accompanied by pictures is an alternative solution. The development method used in the research is Exploration, Explanation, and Evaluate (3E) model. The research was conducted by developing the research result into a booklet based on the diversity of fiddler crabs in mangrove ecosystem. The booklet validation consists of two lecturers from the Department of Biology Education at the University of Muhammadiyah Malang which is a material expert and learning media expert. The result of this research is booklet very valid with the percentage of material expert validity 81.25% and learning media expert 95.13%.

Assessment of Crab Limb Regeneration as an Assay for Developmental Toxicity

1992 ◽  
Vol 49 (6) ◽  
pp. 1268-1273 ◽  
Author(s):  
Anthony S. Clare ◽  
John D. Costlow ◽  
Hassan M. Bedair ◽  
George Lumb
Keyword(s):  
Developmental Toxicity ◽  
Limb Regeneration ◽  
Optimal Conditions ◽  
Mud Crab ◽  
Rhithropanopeus Harrisii ◽  
Full Size ◽  
Juvenile Crab ◽  
Sublethal Concentrations ◽  
Crab Stage ◽  
Duration Of Development

The regeneration of a cheliped that is autotomised at the final larval stage, the megalopa, of the mud crab Rhithropanopeus harrisii (Gould) forms the basis of an assay for developmental toxicity. Cheliped regeneration is followed through to the third juvenile crab stage; a regenerate that is approximately two thirds full size normally emerges at the moult to the second crab, and full size is attained at crab 3. The absence of a regenerate at crab 2, or a regenerate that is smaller than normal and/or malformed, is scored as abnormal regeneration. Other parameters examined in this assay include survival and duration of development. The assay is of comparatively short duration (approximately 2 wk), and survival is high following autotomy under optimal conditions. Four insecticides and a herbicide have been tested in the assay at lethal and sublethal concentrations. Of these compounds, methomyl, carbofuran, and alachlor induced abnormal regeneration whereas cypermethrin and RH 5849 did not affect regeneration at the concentrations tested. Although reproducibility of results needs improvement, crab limb regeneration is otherwise a practical assay for developmental toxicity.

Variation of Sediment Properties among the Radial Profiles of Fiddler Crab Burrows in Mangrove Ecosystem

2015 ◽  
Vol 12 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Mohammad Mokhtari ◽  
Mazlan Abd Ghaffar ◽  
Gires Usup ◽  
Zaidi Che Cob
Keyword(s):  
Fiddler Crab ◽  
Mangrove Ecosystem ◽  
Sediment Properties ◽  
Radial Profiles

Burrowing-site selection by the soldier crab Mictyris guinotae Davie, Shih & Chan, 2010 (Decapoda: Brachyura: Mictyridae)

2020 ◽  
Vol 40 (2) ◽  
pp. 147-151
Author(s):  
Satoshi Takeda
Keyword(s):  
Site Selection ◽  
Tidal Flat ◽  
Chemical Cues ◽  
Fiddler Crab ◽  
Tidal Flats ◽  
Night Time ◽  
Deposit Feeders ◽  
Transition Area

Abstract The soldier crab Mictyris guinotae Davie, Shih & Chan, 2010 inhabiting sandy tidal flats in the Ryukyu Is., Japan, are deposit feeders in two regions: its upper habitat where it burrows and the shoreline. The crabs usually migrate between these two regions during the period of emergence at the daytime and night-time low tide. The aim of this study was to determine which kind of sediments are chosen by the crabs when burrowing. Experiments designed to investigate burrowing-site selection revealed that the crabs preferably burrowed in sediment that had been conditioned through feeding by conspecific crabs, but not in sediment that had been conditioned by conspecific crabs walking on its surface. Moreover, the crabs never showed any preference for burrowing in sediment that had been conditioned through feeding by the competitor fiddler crab Austruca perplexa (H. Milne Edwards, 1852); both soldier (prey) and fiddler (predator) crabs sympatrically inhabit the tidal flat, but segregate their habitats with a transition area. These results suggest that chemical cues in sediment conditioned through feeding by conspecific soldier crabs affect where crabs burrow.

scholarly journals Description of the first juvenile stage of the fiddler crab Minuca mordax (Smith, 1870) (Crustacea, Decapoda, Ocypodidae)

2016 ◽  
Vol 56 (14) ◽  
pp. 163 ◽  
Author(s):  
Salise Brandt Martins ◽  
Murilo Zanetti Marochi ◽  
Setuko Masunari
Keyword(s):  
Ovigerous Female ◽  
Fiddler Crab ◽  
Juvenile Stage ◽  
Juvenile Instar ◽  
Crab Stage

The first stage of the fiddler crab Minuca mordax is described here. Zoea larvae obtained from four ovigerous female were reared in the laboratory until the development of the first crab stage. The development from zoea I to the first juvenile instar lasted 35 days after hatching. The first crab stage of Minuca mordax can be morphologically distinguished from those of Minuca burgersi and Leptuca cumulanta by a 2‑segmented antennule endopod (3‑segmented in M. burgersi, unsegmented in L. cumulanta), an unsegmented maxillule endopod (2‑segmented in M. burgersi and L. cumulanta), and a 4‑segmented first and second maxilliped endopod (respectively unsegmented and 5‑segmented in M. burgersi and L. cumulanta). The three species have the following characters in common: segmented peduncle of antennule 2; endopod of antennule unsegmented; presence of aesthetascs on the antennule; peduncle of antenna 3‑segmented; flagellum of antenna 6‑segmented; mandible 3‑segmented; maxilla with coxal and basal endite bilobed; first, second and third maxillae with exopod 2‑segmented and abdomen with six somites that are wider than long.

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