Crabs

Observations of deep-sea homolids are becoming more common, but good-resolution imagery of these crabs in the natural environment is still scarce. Sixteen new in situ observations of Paromola cuvieri from various locations of the Azores Archipelago (Northeast Atlantic) are described here based on video footage collected by two submersible vehicles. Crabs were found on coral gardens and deep-sea sponge aggregations, which are priority habitats of conservation importance under OSPARCOM. Diverse sessile megafauna were recorded (>59 taxa), including sponges, hydroids, corals, brachiopods, crinoids and oysters. Overall, 75% of the crabs were carrying live specimens of sessile invertebrates, mainly sponges and cold-water corals. Object selection shows to be a more complex process than previously thought, in which factors such as morphology, size and weight of objects and also palatability seem to be more important in the process of object selection than their availability.

This visual guide is illustrated with images captured by Anadarko Colombia Company (ACC), a subsidiary of Anadarko Petroleum
Corporation (APC), during its normal offshore hydrocarbon exploration process at depths between 375 and 3288 m in the Colombian Caribbean Sea. Images were taken by towed camera, Remote Operated Vehicle (ROV), and by samples taken in Piston Core projects. Images were classified by large taxonomic groups. National experts were contacted to identify the organisms to the most specific taxonomic level possible. International experts were also contacted to confirm organisms previously identified or to identify those for which no national expert
was available. This guide includes introductions for each major taxonomic group and other ones for more specific groups (if applicable),
provided by the experts themselves, who participated in the identification of the organisms. This is the first visual guide of
deep-sea organisms (mega fauna) for the Colombian Caribbean.

Arthropods
ISSN 2224-4255
http://www.iaees.org/publications/journals/arthropods/articles/2019-8(4)/2019-8(4).asp

Volume 8, Number 4, 1 December 2019

Cover Pages
[Front Pages (94K)] [Back Pages (55K)]

Articles

Walking leg regeneration observed in three families and four species of antarctic sea spiders
Arthropods, 2019, 8(4): 110-117
John A. Fornshell
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First record of the crab, Droippe quadridens (Fabricius, 1793) (Brachyura: Dorippidae), from the Iraqi coastal waters of the NW Arabian Gulf, with notes on the occurrence of seven species of crabs in the region
Arthropods, 2019, 8(4): 118-126
KhaledKh Al-Khafaji, Tariq H.Y. Al-Maliky, Anwar M.J. Al-Maliky
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Xylophagous millipede surface area to volume ratios are size dependent in forests
Arthropods, 2019, 8(4): 127-136
Mark Cooper
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Size dimorphism in six juliform millipedes
Arthropods, 2019, 8(4): 137-142
Mark Cooper
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Inventory of freshwater arthropods in Pakistan
Arthropods, 2019, 8(4): 143-175
Quddusi B. Kazmi, Farhana S. Ghory
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Crabs has been known inhabiting diverse habitat. Crabs were found in the sea, and some other species were found in terrestrial or freshwater. Crabs is one of the important biotic components of the aquatic ecosystem as detrivore. Opak River is one of the major rivers in the Daerah Istimewa Yogyakarta (DIY), which has a various conditions and direct impact on biodiversity including the diversity of crabs. Up to now, there is no database of crab species from Yogyakarta. The aim of this research was to determine the diversity of crabs from Opak River. Research were carried out for 5 months between June and October 2013. Samples were characterized and identified morphologically. The results show that there are five species of crabs in Opak River. Parathelphusa convexa (De Man, 1879) was commonly found from upstream to downstream. Varuna litterata (Fabricius, 1798) was found in downstream to estuary (brackish water). The other three species were only found in the estuary area viz. Ocypode ceratophthalma (Pallas, 1772), Episesarma versicolor (Tweedie, 1940), and Scylla serrata (Forsskål, 1775). It can be concluded that diversity of crabs in the Opak River estuary area is higher than the upstream and downstream areas.

Charybdis feriata supports trawl fishery of Karnataka coast and the entire catch is landed by multiday trawlers
operating beyond 30 m depth zone. The highest landing was observed during 2003 (142 t). Fishing season for
the species extend generally from September to June but peak fishing season of the species was during
December-June. Size range observed in the fishery was 46 to 170 mm in males and 26 to 155 mm in females.
Mean size ranged from 66 mm to 80 mm. Test of homogeneity of the sex ratio (χ2 test) for the years, 2007-2009
showed that proportion conform to 1:1 ratio. Studies conducted on reproductive stages of the species show that
the species is a continuous breeder with two peak breeding season, one during October–November and another
during May-June. Size at maturity (50%) of females was estimated at 70 mm carapace width and age at 50%
maturity was about 7 months. Carapace width-weight studies showed that males were heavier than females of
similar size. By von Bertalanffy’s growth plot, it was estimated that males and females reach 101mm, 99 mm
(CW) respectively at the end of first year and reach 142 mm and 137 mm respectively in two years. Stock
assessment studies of the species was conducted using sex pooled data for the period 2007-2009 so as to formulate
management suggestions. The Z, M and F values estimated for the species were 6.04, 1.76 and 4.28 respectively.
The exploitation ratio (E) was 0.71. MSY was estimated as 131t against the present annual average yield of
124 t. From ‘Thompson and Bell yield prediction analysis’ it is seen that any additional 10% effort from the
present level will yield only less than 10% additional catch, indicating that increasing the effort for better catch
of the resource will not be economical and it is suggested that restricting the catch to MSY level (131 t) will be
the suitable management option for the sustainability of C. feriata fishery from the coast.
Keywords: Biology, Charybdis feriata, Crucifix crab, Exploitation, Karnataka coast

Kualitas pakan alami larva kepiting bakau, Scylla serrata dapat ditingkatkan dengan pengayaan terlebih dahulu sebelum diberikan ke larva. Tujuan penelitian adalah untuk mengetahui jenis pengkaya terbaik untuk nauplius Artemia yang dijadikan pakan larva kepiting bakau stadia zoea-3 hingga stadia megalopa dengan indikasi terjadi peningkatan rasio DHA/EPA, vitalitas larva meningkat, produksi krablet menjadi lebih banyak. Larva yang baru menetas dan sehat dipelihara di 12 unit bak fiber kerucut volume 250 L diisi air laut steril sebanyak 200 L masing-masing dengan padat tebar 100 ind./L. Larva diberi pakan rotifer dan nauplius Artemia yang sudah diperkaya dengan HUFA. Selain itu, nauplius artemia juga dikayakan dengan beberapa jenis pengaya lainnya sebagai perlakuan yaitu a). nauplius Artemia tidak diperkaya dengan jenis pengaya lainnya, b). nauplius Artemia diperkaya dengan Nannochloropsis sp., c). nauplius Artemia diperkaya dengan vitamin C, dan d). nauplius Artemia diperkaya dengan Nannochloropsissp. dan vitamin C. Masing-masing perlakuan dengan tiga kali ulangan. Monitoring dilakukan pada rasio DHA/EPA pada naupliusArtemia yang diperkaya dengan jenis pengkaya berbeda, perkembangan dan populasi larva, kualitas air, populasi Vibrio sp., total hemosit dan produksi krablet dari setiap perlakuan. Hasil penelitian menunjukkan bahwa rasio DHA/EPA pada nauplius artemia yang diperkaya dengan Nannochloropsis sp. adalah tertinggi dibandingkan dengan jenis pengkaya lainnya. Nilai Indeks Perkembangan Larva yang tertinggi adalah di perlakuan B (4,91) disusul oleh larva di perlakuan C (4,85), kemudian larva di perlakuan A dan D masing-masing dengan (4,58). Jumlah krablet D-10 terbanyak di perlakuan B (109,5 ± 36,1 ekor), disusul perlakuan C (82,0 ± 26,9 ekor), keduanya tidak berbeda nyata (P>0,05) tetapi keduanya berbeda nyata dengan produksi krablet di perlakuan D (33 ± 21,21 ekor) dan perlakuan A (27,5 ± 12,02 ekor). Produksi krablet tertinggi di perlakuan B tersebut didukung dengan jumlah sel haemosit tertinggi pada larva zoea-5 di perlakuan B.

Arthropods
ISSN 2224-4255

http://www.iaees.org/publications/journals/arthropods/articles/2017-6(2)/2017-6(2).asp

Volume 6, Number 2, 1 June 2017

Cover Pages
[Front Pages (140K)] [Back Pages (49K)]

Articles
Observations of the sound producing organs in achelate lobster larvae
Arthropods, 2017, 6(2): 36-46
John A. Fornshell
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New record of the snapping shrimp Alpheus edwardsii (Audouin, 1826) (Crustacea: Alpheoidea) in Basrah, Iraq
Arthropods, 2017, 6(2): 47-53
Tariq H. Y. Al-Maliky, Khaled Kh Al- Khafaji, Talib A. Khalaf
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New records of xanthid crabs Atergatis roseus (Rüppell, 1830) (Crustacea: Decapoda: Brachyura) from Iraqi coast, south of Basrah city, Iraq
Arthropods, 2017, 6(2): 54-58
Khaled Khassaf Al-Khafaji, Aqeel Abdulsahib Al-Waeli, Tariq H. Al-Maliky
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Epidemiological study of scabies among school going children in district Haripur, Pakistan
Arthropods, 2017, 6(2): 59-66
Samina Yasmin, Hanif Ullah, Muhammad Inayat Ullah Khan, Suleman, Sadia Tabassum, Sardar Azhar Mehmood
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Side effects of thiacloprid+deltamethrin, pirimicarb and pymetrozine on the black bean aphid parasitoid, Lysiphlebus fabarum Marshall (Hymenoptera: Aphidiidae)
Arthropods, 2017, 6(2): 67-77
Ardavan Mardani, Ali Almasi, Seyed Mehdi Hashemi, Majid Mohammadnejad
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In this study, a buckler crab, Cryptopodia angulata, reported for the first time from Majali, Karwar, West coast of India. This species occurs rarely in the Indian coastal waters and this is the first report from Karwar coast. External characters have been photographed and examined.

Kerala is the largest freshwater crab-rich state in India. Out of 120 species of Indian freshwater crabs,
Kerala is home for 35 gecarcinucid species (nearly 30%) in 14 genera. The Kerala part of the Western Ghats includes
26 species, which is about 45% of the total species (58 species) in the Western Ghats of India. Moreover, nearly twothirds
species (23 species) and six genera of freshwater crabs are endemic to the state. This paper provides a systematic
list and systematic account of all the freshwater crabs known so far from Kerala. An identification key is also provided.

In the present paper the authors record the occurrence of two hermit crabs, Coenobita brevimanus Dana and C. rugosus
H. Milne-Edwards, for the first time from the Indian coast. The records show the extended distribution of both the species
of hermit crabs and suggest their possible continuous distribution from the east coast of Africa to the south-west Pacific Ocean.

The evolutionary origin of frog crabs (Raninoida) remains puzzling partly due to their astonishing morphological disparity, ranging from broad and heavily ornamented ‘crab’–like extinct families (necrocarcinids and allies), to elongate and smoother ‘frog’–looking extant ones (raninids and allies). However, an ancient Cretaceous clade (Palaeocorystidae) displays a combination of plesiomorphic and apomorphic traits that might advocate for either evolutionary scenario: from ‘crab–like’ to ‘frog–like, or vice versa. This lack of agreement is partly fuelled by the scarcity of Early Cretaceous fossils, a time from which the first raninoidans are known. A close re-examination of an Early Cretaceous fossil from the Santana Group of Brazil, Araripecarcinus ferreirai Martins–Neto, 1987, combined with phylogenetic analysis including all main clades of podotreme crabs, reinforces its raninoidan condition, and rejects the initial hypothesis of a Portunoidea affinity. Furthermore, comparisons with other raninoidans support the hypothesis that a more ‘crab–like’ body plan is the plesiomorphic condition for raninoidans, and that the ‘frog–like’ architecture of Palaeocorystidae, and perhaps the Raninoidea as a whole, reflects a derived condition related to a specialized burrowing lifestyle. Phylogenetic analyses are fundamental to evaluate the position of Palaeocorystidae with respect to raninoidean and necrocarcinid–like families, helping to better resolve the Raninoida evolutionary tree of life, and to gain a broader understanding on their relatedness by common ancestry throughout geological time (full text and supplementary materials can be downloaded here  http://www.tandfonline.com/doi/suppl/10.1080/14772019.2013.871586#tabModule)

Alien species are organisms introduced into an area outside of their natural range and are considered a major cause of biodiversity loss in the marine environment. The aim of this work is to report on the alien crustacean species observed in Ecuador. A bibliographic review was conducted using a digital search in the scientific literature. A total of ten alien species of crustaceans, representing eight genera in seven families, were encountered in Ecuador. The only crab, Cardisoma crassum Smith, 1870, was observed in the Galapagos Islands. The other species include barnacles, crayfishes, and freshwater prawns. Native ranges of the alien crustaceans include the Indo-Pacific region, North America, Asia, and Australia. Major introduction pathways are aquaculture and transport by ship. Procambarus alleni (Faxon, 1884) was reported recently as an aquarium species, but its presence in the natural environmental is currently unknown. One alien species has been introduced each decade since the 1960s. Some species (the barnacles Amphibalanus improvisus (Darwin, 1854), Amphibalanus reticulatus (Utinomi,

The present investigations will be helpful to fishers and policy makers for providing baseline data for the conservation and management aspects of the fishery resource for future purpose. The biological study on Portunus sanguinolentus (Herbst, 1783) was conducted at Veraval coast of Gujarat. It is exploited by the use of trawler throughout the year by the coast. The biological information of crab such as length composition, length-weight relationship, sex ratio, maturity and gonadosomatic index were collected from the multiday trawler operated along the coast. A total 480 crab specimens were studied in the size range from minimum 34.6 mm to maximum 270.2 mm carapace length comprising of 224 males and 256 females. The highest observed length of the crab was 270.2 mm with a mean length of 109 ± 26 mm. The overall sex ratio was 1:1.14. Gonadosomatic index was the highest during March. Sexual maturity indicated that maturation takes place all throughout the year. Gonadosomatic index was higher in the month of August, December, February and March.

In this study we tested the effect of population density on agonistic interactions in male Uca leptodactyla Rathbun, 1898. We recorded the crab’s behaviour in pairs or in groups of five animals composed of conspecifics and heterospecifics living in the same area (sympatric) and distinct areas (allopatric) of the mangrove forest. Allopatric conspecific crabs showed higher approaching and signalling than those in other conditions. The higher the crab density, the lower the interaction intensity between animals. Low-level agonistic signals were mainly displayed in high density (groups), while claw touch mainly occurred in pairs. Allopatric conspecifics showed the more intense agonistic interactions. Therefore, Uca seems to decrease energy investment in unnecessary fights against sympatric and conspecific crabs. Population density is a major factor driving agonistic behaviour mainly when conspecific animals are kept together. This may occur due to the increased
competition for the same resources.

A new species of the hermit crab genus Diogenes Dana, 1851 (Diogenidae), D. canaliculatus, is described and illustrated
on the basis of material from off the Kerala State, southern India. It is referred to the D. edwardsii (De Haan, 1849) species
group, and compared with D. bicristimanus Alcock, 1905, D. fasciatus Rahayu & Forest, 1995, D. laevicarpus Rahayu,
1996 and D. moosai Rahayu & Forest, 1995. The characteristically sculptured left chela and the unarmed dorsal margins
of the propodi of the second and third pereopods distinguish the new species from these congeners.

A new species of Carcinoplax H. Milne Edwards, 1852 (family Goneplacidae) is described from southern India. Carci-noplax fasciata n. sp. is closest to C. specularis Rathbun, 1914, but can be distinguished by its different coloration in life as well as structures of the carapace surface, anterolateral armature, supraorbital margin, chela and male first gonopod.

Ghost fishing, the capture and killing of marine organisms by lost or abandoned fishing gear, is a serious ecological and economic problem confronting fisheries. In this study, we quantify the rate of ghost fishing on the population of red king crab (Paralithodes camtschaticus) in Womens Bay, Kodiak Island, Alaska. From 1991 to 2008, crabs with carapace lengths (CLs) from 42 to 162 mm were tagged with acoustic tags and tracked both from a boat at the surface and by divers. Diver observations were used to determine whether a crab molted or died and, in many cases, to determine the cause of death. Of 192 crabs tracked during this study in association with other projects, 13 were killed in ghostfishing gear (12 in ghost crab pots and 1 in a ghost gill net) and 20 were captured in ghost pots and released alive by divers. An additional 13 died of other causes, including predation by sea otters and an octopus and poaching by humans. We estimate that between 16% and 37% of the population of red king crab with CLs >60 mm in Womens Bay were killed by ghost fishing per year during the period of this study, making ghost fishing a substantial source of mortality. These results indicate that steps to reduce ghost fishing in Womens Bay are warranted.

The present study compared the carapace structure of Carcinus maenas in two nearby sites (2 km apart) within Minho estuary, submitted to different physicochemical and ecological conditions (water temperature, pH, crabs’ density and sex ratio). The carapace structure of the carapace and chelae of the crabs presented significant differences between sampling sites (t-test; p < 0.01). The SIMPER analysis revealed that the Weight/CW and Thickness/CW ratios explained all the dissimilarities found among sites. Overall, the male carapace was proportionally thicker at station 2 (t-test; p < 0.01), while the female carapace was proportionally thicker at station 1 (t-test; p < 0.001). A thicker carapace can be advantageous when competing for food or a sexual partner. We hypothetized that, since at station 2, the density of individuals was twice higher than at station 1, it is likely that agonistic encounters are more frequent, thus favouring a thicker carapace.

A new raninoidian crab, Bellcarcinus aptiensis gen. nov., sp. nov., is described from the upper Aptian of Colombia. The new genus displays a combination of traits seen among some ancient species within the Necrocarcinidae and Orithopsidae, obscuring its family placement. This taxon represents the sixth known genus of pre-Albian raninoidians worldwide, and the fourth known from Colombia, in addition to Joeranina, Planocarcinus and Colombicarcinus. Bellcarcinus gen. nov., together with other Early Creta- ceous finds from Colombia and Brazil, represents early stocks of stem-group frog crabs, which indicate that tropical South America might have played an important role in the early radiation of the group.

Understanding the biology of offshore species in hardened by the difficulties of sampling in the deep-sea environment. Additionally, due to the vastness of the open ocean, knowledge of early life histories of pelagic larvae is still relatively scarce. In decapod species with bentho-pelagic lifestyle, the transition from life
in the seafloor to the water column not only is associated with drastic
morphological metamorphosis, but also with changes in behavior and feeding
ecology. The purpose of the present thesis was to investigate physiological,
biochemical and behavioral adaptation occurring during early development of such species. The Norway lobster, Nephrops norvegicus, and the crab Monodaeus couchi were used as a model as these two species are encountered off the NE Atlantic shelf at depth greater than 300 m.
Chapter 1 introduces the challenges faced by both adult and larvae inhabiting
such remote habitats, including the effect of food availability on development
and oceanographic processes on dispersal and recruitment. The thesis follows
early life histories, starting with within-brood variability in the fatty acid (FA) profile displayed by developing N. norvegicus embryos. There were no differences in the FA composition of embryos sampled from both sides of the brooding chamber in most females. However, all females exhibited significant differences in the FA profiles of embryos sampled from different pleopods.
Potential causes for the variations recorded may be differential female investment during oocyte production or shifts in FA catabolism during the incubation period promoted by embryo’s location within the brooding chamber. Next, feeding rates and digestive enzymes activity of the early stage larvae was investigated in N. norvegicus. Both stages were able to maximize food intake when larvae were scarce and showed increased feeding rate following periods of starvation. Amylase activity indicated that carbohydrates are not the primary energy reserve and that feeding may be required soon after hatching to trigger amylase activity. Protease activity indicated that protein reserves are catabolized under starvation. These results indicate that larvae may maximize prey ingestion in the presence of plankton patches with higher food abundance and minimize the deleterious effects induced by previous periods of intermittent starvation or unsuitable prey densities/types.
Additionally, changes in enzymatic activity may allow newly hatched N. norvegicus larvae to metabolize protein reserves to overcome short-term starvation. Vertical migration behavior and the influence of oceanographic properties were studied next. All zoeal stages of M. couchi displayed reverse diel vertical migration. Abundance of early stages was correlated with chlorophyll a levels. An ontogenic shift in vertical distribution explained the
results; earlier zoeal stages remain in the food-rich upper water column while later stages migrate to the bottom for settlement. This vertical migration behavior is likely to affect horizontal distribution of larvae. Indeed, global current patterns will result in low inter-annual variations in decapod larvae recruitment, but short term variations such as upwelling events will cause
deviation from the expected dispersal pattern.
Throughout development, from the embryo to metamorphosis into benthic juvenile, offshore decapods face many challenges. For the developing individual survivorship will depend heavily on food availability but also on the reserves passed on by the mother. Even though vertical migration behavior can allow the larvae to take advantage of depth varying currents for transport, the effect of general circulation pattern will superimpose local current and influence feeding conditions and affect dispersal and recruitment.