scholarly journals Erratum

1997 ◽  
Vol 13 (4) ◽  
pp. 578-578
Author(s):  
P. Green

Green, P. T. (1997)Red crabs in rain forest on Christmas Island, Indian Ocean: activity patterns, density and biomass. Vol. 13 Part 1: 17–38. On page 29 the phrase: “but a significant correlation existed across sites (r=0.81, n=44, P<0.001).” should read: “but a significant correlation existed across sites (r=-0.69, n=44, P<0.001).”On page 33 the phrase “but the same correlation accounted for 81% of total variation when all sites were analysed together.” should read: “but the same correlation accounted for 48% of total variation when all sites were analysed together.”

1997 ◽  
Vol 13 (1) ◽  
pp. 17-38 ◽  
Author(s):  
Peter T. Green

ABSTRACTThe red crab Gecarcoidea natalis is the most abundant land crab on Christmas Island, Indian Ocean, and is found wherever native rain forest is still intact. The largest crabs grow to > 120 mm carapace width and reach > 500 g in mass. Red crabs are diurnally active, and moisture appears to be the most important factor governing surface activity – activity was nil below 77% RH, relatively low at 87% RH, and high above 95% RH. The crabs retreat to the interior of their burrows during dry periods, but emerge rapidly in response to rain. Because of their dependence on moisture for surface activity, red crabs show greater levels of activity during the wet season. Annual breeding migrations and moulting activity decreased the density of surface-active crabs at the main study sites for several weeks at the start of the wet season, and fruit and leaf fall caused dramatic local increases in the density of active red crabs. Density and biomass at the main study sites averaged 1.3 crabs m-2 and 1454 kg ha-1, respectively, and 1.2 crabs m-2 and 1137 kg ha-1 at a total of five sites across the island. Rough calculations suggest that the island-wide population is at least 100 million individuals. Red crabs are the dominant consumer on the forest floor, and consume seeds, seedlings and leaf litter. Because they are both abundant and widespread, these animals have the potential to be the most important determinant of pattern and process in rain forest on Christmas Island.


Oikos ◽  
1990 ◽  
Vol 58 (3) ◽  
pp. 289 ◽  
Author(s):  
Dennis J. O'Dowd ◽  
P. S. Lake
Keyword(s):  

2017 ◽  
Vol 22 (3) ◽  
pp. 139
Author(s):  
Nurulludin Nurulludin ◽  
Thomas Hidayat ◽  
Asep Mamun

Kepadatan stok ikan merupakan indikasi dari potensi perikanan di suatu wilayah yang sangat penting diketahui. Tujuan tulisan ini membahas tentang laju tangkap, kepadatan stok dan perkiraan biomassa ikan demersal serta udang. Penelitian sumber daya ikan demersal dan udang di Samudera Hindia Barat Sumatera dilakukan dengan menggunakan Kapal Riset Baruna Jaya IV (1.200 GT) pada bulan Oktober dan November 2015 (Musim peralihan II). Penghitungan kepadatan stok menggunakan metode sweept area dengan panjang tali ris atas dari jaring trawl 36 m, kecepatan kapal saat menarik jaring berkisar 2,5 – 3 knot, lama penarikan jaring maksimal 1 jam. Perairan Samudera Hindia Barat Sumatera terdiri dari 151 spesies yang tergolong dalam 59 famili. Famili ikan demersal yang dominan tertangkap (5 besar), yaitu Leiognathidae sebesar 23,6 %, Trichiuridae 9,8%, Haemulidae 8,0%,  Engraulididae 6,6%, dan Polynemidae 6,05%. Famili udang yaitu Penaeidae (79,08%), Scyllaridae 19,49%, dan Solenoceridae 1,43%. Rata-rata laju tangkap ikan demersal 205,80 kg/jam, dengan kepadatan stok 6,66 ton/km2 dan udang 2,30 kg/jam dengan kepadatan stok 0,053 ton/km2. Biomassa ikan demersal diperkirakan sebesar 470.122 ton dan udang 3.706 ton.  Fish stock density  is an index of stock abundance indicating the fish resources potential in a region.  This paper discusses the catch rate, stock density and biomass estimates of the demersal fish and shrimp resources. Research on the demersal fish and shrimp resources in the Indian Ocean-Western Sumatera conducted using the Research Vessel Baruna Jaya IV (1200 GT) carried out during  October and November 2015 (2nd intermonsoon season). Stock density was estimated through the swept area method. The trawl used has 36 m headrope, trawling speed of 2.5 - 3 knots, and maximum towing time was 1 hour. It was found that the fish resources in the waters of the Indian Ocean-Western Sumatera consisted of 151 species belonging to 59 families. The top five dominant fish families caught were Leiognathidae of 23.6%, Trichiuridae 9.8%, Haemulidae 8.0%, Engraulididae 6.6%, and Polynemidae 6.05%, while the shrimp families were Penaeidae of 79.08%, Scyllaridae 19.49%, and Solenoceridae 1.43%. The average catch rate of demersal fish was 205.80 kg/hour, with a stock density of 6.66 tons/km2 and shrimp of 2.30 kg/hour with a stock density of 5.3 kgs/km2. The estimated biomass of demersal fish was  470,122 tons and shrimp was 3,706 tons.  


1995 ◽  
Vol 9 (2) ◽  
pp. 243 ◽  
Author(s):  
TR New

A new species of Zorotypus Silvestri, Z. lawrencei, sp.nov., is described from female specimens collected on Christmas Island, marking the first species of the insect order Zoraptera from an Australian territory.


Sign in / Sign up

Export Citation Format

Share Document