DESCRIPTION AND BIOLOGY OF A NEW SPECIES OF 



PELAGIC PENAEID SHRIMP, BENTHEOGENNEMA BURKENROADI, 



FROM THE NORTHEASTERN PACIFIC 



Earl E. Krygier- and Robert A. Wasmer^ 



ABSTRACT 



The new species of pelagic penaeid shrimp lacks the richly plumose arthrobranch described for the 

 genus and has a single pair of terminal spines on the telson. It is found mainly in transitional water of 

 the North Pacific between 500 and 1,000 m by day and 150 and 1,000 m at night. Examination of testes 

 and ovaries, and the structures of the petasma and thelycum, indicates a 4-5 mo spawning season and an 

 equal male to female sex ratio. Generation time was estimated to be 2 yr. 



This paper describes the systematics and biology 

 of a new species of pelagic penaeid shrimp of the 

 genus Bentheogennema. Since 1961, studies of the 

 fauna and ecology of the mesopelagic waters off 

 the coast of Oregon have been conducted by 

 members of the School of Oceanography, Oregon 

 State University. Several unusual species of 

 macrurous decapod Crustacea have been obtained. 

 The discovery and identification of this new 

 species of Bentheogennema was by Carl Forss, who 

 entrusted his material to the authors. Subsequent 

 sampling with mid-water trawls has provided de- 

 tailed information on the distribution and 

 biologyof this shrimp, as well as abundant 

 material for taxonomic description. 



METHODS AND MATERIALS 



Material for the zoogeographic distribution was 

 collected in Isaacs-Kidd Mid-water Trawls (IKMT) 

 from the research vessels Yaquina, Endeavor, 

 John R. Manning, and Hugh M. Smith in the 

 northeastern Pacific, normally within 320 m of the 

 surface (Wasmer 1972). Information on vertical 

 distribution, reproductive biology, and growth of 

 this species was obtained from samples taken on 

 five cruises aboard RV Yaquina at a single 

 sampling station 65 nautical miles (120 km) off the 

 central Oregon coast (NH 65-lat. 44°35'N, long. 



'Research supported by the Ofhce of Naval Research (Contract 

 NOOO- 14-67- A-0369-0007 under project NR 083-102) and the 

 Atomic Energy Commission (Contract AT[45-1] 2227, Task 

 Agreement 12). Publication number RL0-2227-T12-51. 



-School of Oceanography, Oregon State University, Corvallis, 

 OR 97331. 



'School of Oceanography, Oregon State University, Corvallis, 

 Oreg.; present address: Bass Memorial Academy, Lumberton, MS 

 39455. 



125°25'W) in 1972-73. Samples at this station were 

 taken both day and night, using an 8-foot IKMT 

 with a five net opening-closing cod end section 

 similar to the one described by Pearcy and 

 Mesecar (1971). 



All samples were preserved at sea in 10% buf- 

 fered Formalin.' The samples were later sorted, 

 identified, sexed when possible, and measured. 

 Carapace length (measured from the postorbital 

 margin to the median posterior edge of the 

 carapace) was used as an indication of size. All 

 figures were drawn with the aid of a camera lucida. 



In males, sexual maturity was based on three 

 characteristics: 1) petasmata joined; 2) well- 

 developed accessory lobe on anterior surface of the 

 petasma; 3) and dilated vas deferens with large 

 terminal ampoule (indicative of developed sper- 

 matophore) at the base of the fifth pereiopod. The 

 combined characteristics of fully developed 

 thelycum and the posterior lateral lobe of the 

 ovary swollen with eggs at the base of the fifth 

 pereiopod were used as signs of sexual maturity in 

 females. Estimates of growth are presented from 

 analysis of length-frequency data. 



Section Penaeidea 



Family Penaeidae Bate 



Subfamily Aristaeinae Alcock 



Series Benthesicymae Bouvier 



Bentheogennema hurkenroadi n. sp. 



ri/pes.-Holotype (USNM 150835), male, 

 carapace length (c.l.) 18 mm, from Station lat. 



Manuscript accepted January 1975. 

 FISHERY BULLETIN: VOL. 73, NO. 4, 1975. 



'Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



737 



