Morphometric measurements and gonad examination of the spider crab, Chionoecetes opilio, showed that 50% maturity occurred at about 57 and 50 mm carapace width for males and females, with minimum sizes at maturity of 51 (males) and 47 mm (females). Both sexes were mature at sizes considerably below the commercially acceptable size of 4 inches (102 mm) carapace width. After maturity, positive allometric growth was demonstrated for males. Females do not moult after reaching maturity. The small vasa deferentia found in soft-shelled mature males suggested that only hard-shelled males were capable of mating. A hard-shelled male successfully mated with a soft-shelled mature female. Field and laboratory observations suggest that more than one brood is commonly produced from one mating.The minimum size limit for commercial landings allows some mature males capable of mating to be left on the fishing grounds. Retention of this limit seems unlikely to affect the breeding potential of the population.

Twelve termite mounds and adjacent Ah and Ap horizons were sampled at three sites near Salisbury, Rhodesia. The mass of termite mounds occupied by M. fulciger at one site was estimated at 620 tlha, and contained the following amounts of nutrients expressed as percentages of the amounts in mounds and Ap horizon combined: extractable Ca 9570, mineral N 81% extractable K 69%, and available P 69%.Pot experiments using perennial ryegrass gave higher dry matter yields from termite mounds than from the Ap and Ah horizons. Crop production could therefore be increased by mixing termite mounds with the soil. IntroductionHow should the subsistence farmer best utilize large termite mounds: should he avoid cropping termite mounds, should he grow crops on mounds o r should he spread mounds over the surrounding soil? Pendleton (1941), working in Thailand, found that termite mounds, which were finer textured, more fertile and better drained than surrounding soil, carried upland crops (cotton, tobacco and maize) which did not thrive on the surrounding paddy fields. He stated that the destruction of mounds was seldom advisable. Hesse (1955) observed that sisal in Tanzania grew better on Macrotermes mounds than on surrounding shallow or poorly drained soil. He concluded that in these circumstances a termite mound was beneficial mainly because it was a mound and not because it was composed of special soil. Doop (1938) reported from Java that thorough mixing of termite mounds with surrounding soil resulted in an increase in sisal production. His termite mounds contained more calcium, magnesium and available nitrogen than adjacent soils. Meyer (1960) reported that the central portions of large (4-6 m high), old termite mounds in Zaire were very infertile and formed large patches of sterile ground when spread on the surface. Nye (1955) found that the topsoil of a collapsed Macrotermes bellicosus mound in Nigeria was lower in nutrients than the surrounding topsoil. He observed that maize grew relatively poorly on levelled off and collapsed mounds. These examples are sufficient t o show that termite mounds, in situ and when mixed with surrounding soil, in some cases enhance crop growth and in other cases retard it. It is therefore necessary t o study the effect of termite mounds as a soil amendment under well defined conditions before making recommendations.

During the week-long precopulatory embrace, the male spider crab, Chionoecetes opilio, held the female, even when attacking intruding males. Before a 45-min copulation period the male assisted female ecdysis. During the postcopulatory embrace spermatophores flowed onto the pleopods of the female. Polygamous males as small as 60 mm width mated with larger females. More than one fertile egg batch was frequently produced from one mating. Females mated successfully up to 95 hr after molting. Hard-shelled females seemed incapable of mating. The probable mating season is February through April and continued recruitment seems assured.

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