Sperm storage is common in internally fertilizing animals, but is also present in several external fertilizers, such as many cephalopods. Cephalopod males attach sperm packets (spermatangia) to female conspecifics during mating. Females of eight externally fertilizing families comprising 25% of cephalopod biodiversity have sperm-storage organs (seminal receptacles) in their buccal area, which are not in direct physical contact with the deposited spermatangia. The mechanism of sperm transmission between the implantation site and the storage organ has remained a major mystery in cephalopod reproductive biology. Here, jumbo squid females covering almost the entire life cycle, from immature to a laboratory spawned female, were used to describe the internal structure of the seminal receptacles and the process of sperm storage. Seminal fluid was present between the spermatangia and seminal receptacles, but absent in regions devoid of seminal receptacles. The sperm cellular component was formed by spermatozoa and round cells. Although spermatozoa were tracked over the buccal membrane of the females to the inner chambers of the seminal receptacles, round cells were not found inside the seminal receptacles, suggesting that spermatozoa are not sucked up by the muscular action of the seminal receptacles. This finding supports the hypothesis that spermatozoa are able to actively migrate over the female skin. Although further experimental support is needed to fully confirm this hypothesis, our findings shed light on the elusive process of sperm storage in many cephalopods, a process that is fundamental for understanding sexual selection in the sea.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Aiken DE, Waddy SL, Mercer SM (2004) Confirmation of external fertilization in the American lobster, Homarus americanus. J Crustacean Biol 24(3):474–480. doi:10.1651/C-2454
Beninger PG, Valdizan A, Le Pennec G (2016) The seminal receptacle and implications for reproductive processes inthe invasive gastropod Crepidula fornicata. Zool 119:4–10. doi:10.1016/j.zool.2015.09.001
Birk MA, Paight C, Seibel BA (2016) Observations of multiple pelagic egg masses from small-sized jumbo squid (Dosidicus gigas) in the Gulf of California. J Nat Hist. doi:10.1080/00222933.2016.1209248
Bush SL, Hoving HJT, Huffard CL, Robison BH, Zeidberg LD (2012) Brooding and sperm storage by the deep-sea squid Bathyteuthis berryi (Cephalopoda: Decapodiformes). J Mar Biol Assoc UK 92:1629–1636. doi:10.1017/S0025315411002165
Fernández-Álvarez FA, Li DH, Portner E, Villanueva R, Gilly WE (2017) Morphological description of egg masses and hatchlings of Lolliguncula diomedeae (Cephalopoda: Loliginidae). J Molluscan Stud 83:194–199. doi:10.1093/mollus/eyx008
Fiorito G, Affuso A, Basil J, Cole A, De Girolamo P, D’Angelo L, Dickel L, Gestal C, Grasso F, Kuba M, Mark F, Melillo D, Osorio D, Perkins K, Ponte G, Shashar N, Smith D, Smith J, Andrews PL (2015) Guidelines for the care and welfare of cephalopods in research: a consensus based on an initiative by CephRes, FELASA and the Boyd Group. Lab Anim 49:1–90. doi:10.1177/0023677215580006
Hanlon RT, Messenger JB (1996) Cephalopod behaviour. Cambridge University Press, New York
Hirohashi N et al (2013) Sperm from sneaker male squids exhibit chemotactic swarming to CO2. Curr Biol 23:775–781. doi:10.1016/j.cub.2013.03.040
Hirohashi N, Iida T, Sato N, Warwick SHH, Iwata Y (2016) Complex adaptive traits between mating behavior and post-copulatory sperm behaviour in squids. Rev Fish Biol Fish 26:601–607. doi:10.1007/s11160-016-9434-1
Hoving H-JT et al. (2014) In: Erica AGV (ed) Advances in marine biology, vol 67. Academic Press, Cambridge, pp 235–359. doi:10.1016/B978-0-12-800287-2.00003-2
Jereb P, Roper CFE (2010) Cephalopods of the world. An annotated and illustrated catalogue of species known to date, vol 2. Myopsid and Oegopsid Squids. FAO species catalogue for fishery purposes, no. 4, vol 2. FAO, Rome
Johanisson E, Campana A, Luthi R, de Agostini A (2000) Evaluation of ‘round cells’ in semen analysis: a comparative study. Hum Reprod Update 6:404–412
Lipinski MR, Underhill LG (1995) Sexual maduration in squid: quantum or continuum? S Afr J Mar Sci 15:207–223
Marian JEAR (2015) Evolution of spermatophore transfer mechanisms in cephalopods. J Nat Hist 49:1423–1455. doi:10.1080/00222933.2013.825026
Markaida U, Gilly WF (2016) Cephalopods of Pacific Latin America. Fish Res 173:113–121. doi:10.1016/j.fishres.2015.09.014
Moltschaniwskyj NA et al (2007) Ethical and welfare considerations when using cephalopods as experimental animals. Rev Fish Biol Fish 17:455–476. doi:10.1007/s11160-007-9056-8
Naud MJ, Havenhand JN (2006) Sperm motility and longevity in the giant cuttlefish, Sepia apama (Mollusca: Cephalopoda). Mar Biol 148:559–566. doi:10.1007/s00227-005-0109-z
Naud MJ, Shaw PW, Hanlon RT, Havenhand JN (2005) Evidence for biased use of sperm sources in wild female giant cuttlefish (Sepia apama). Proc R Soc Lond B Biol Sci 272:1047–1051. doi:10.1098/rspb.2004.3031
Nigmatullin ChM, Arkhipkin AI, Sabirov RM (1995) Age, growth and reproductive biology of diamond-shaped squid Thysanoteuthis rhombus (Oegopsida: Thysanoteuthidae). Mar Ecol Prog Ser 124:73–87
Orr TJ, Brennan PLR (2015) Sperm storage: distinguishing selective processes and evaluating criteria. Trends Ecol Evol 30:261–272. doi:10.1016/j.tree.2015.03.006
Pantin CFA (1968) Técnicas microscópicas para zoólogos. Editorial Academia León, León
Pascini TV, Martins GF (2017) The insect spermatheca: an overview. Zool 121:56–71. doi:10.1016/j.zool.2016.12.001
Reeve MR, Walter MA (1972) Observations and experiments on methods of fertilization in the chaetognath Sagitta hispida. Biol Bull 143:207–214
Sato N, Kasugai T, Ikeda Y, Munehara H (2010) Structure of the seminal receptacle and sperm storage in the Japanese pygmy squid. J Zool 282:151–156. doi:10.1111/j.1469-7998.2010.00733.x
Sato N, Kasugai T, Munehara H (2013) Sperm transfer or spermatangia removal: postcopulatory behaviour of picking up spermatangium by female Japanese pygmy squid. Mar Biol 160:553–561. doi:10.1007/s00227-012-2112-5
Sato N, Yoshida MA, Kasugai T (2017) Impact of cryptic female choice on insemination success: Larger sized and longer copulating male squid ejaculate more, but females influence insemination success by removing spermatangia. Evolution 71:111–120. doi:10.1111/evo.13149
Squires ZE, Wong BBM, Norman MD, Stuart-fox D (2015) Last male sperm precedence in a polygamous squid. Biol J Linn Soc 116:277–287
Staaf DJ, Camarillo-Coop S, Haddock SHD, Nyack AC, Payne J, Salinas-Zavala CA, Seibel BA, Trueblood L, Widmer C, Gilly WF (2008) Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae. J Mar Biol Assoc UK 88:759–770. doi:10.1017/S0025315408001422
Tinbergen L (1939) Zur Fortpflanzungsethologie von Sepia officinalis L. Archs Neerl Zool 3:323–364
van Oordt GJ (1938) The spermatheca of Loligo vulgaris. I. Structure of the spermatheca and function of its unicellular glands. Q J Microsc Sci 80:593–599
Villanueva R et al (2012) A laboratory guide to in vitro fertilization of oceanic squids. Aquaculture 342–343:125–133. doi:10.1016/j.aquaculture.2012.02.025
Waddy SL, Aiken DE (1986) Multiple fertilization and consecutive spawning in large American lobsters, Homarus americanus. Can J Fish Aquat Sci 43:2291–2294
Wegener BJ, Stuart-Fox D, Norman MD, Wong BBM (2013) Spermatophore consumption in a cephalopod. Biol Lett 9:20130192. doi:10.1098/rsbl.2013.0192
We thank Diana H. Li, Hannah Rosen, Elan Portner, Patrick C. Daniel and Timothy H. Frawley for their valuable help in the collection of jumbo squids. Thanks to Mr. J. M. Fortuño (Electron Microscopy Service, ICM) for his dedication and kindness during the SEM sessions and Mr. J. M. Anguita (ICM) for the elaboration of Fig. 2a. We thank the editor and two anonymous reviewers for their helpful comments. This study was funded by the research project CALOCEAN-2 (AGL2012-39077) from the Ministry of Economy and Competitiveness (MINECO) of Spain. FAFA was supported by two Grants (BES-2013-063551 and EEBB-I-15-09631) from MINECO. HJTH was financed by a Grant (CP1218) of the Cluster of Excellence 80 “The Future Ocean”, funded within the framework of the Excellence Initiative by the Deutsche Forschungsgemeinschaft (DFG) on behalf of the German federal and state governments. Support from Grants OCE-1338973 RAPID, IOS-142093 EAGER, OCE 0850839 and IOS-1557754 (US National Science Foundation), and N000140911054 (US Office of Naval Research) is also acknowledged.
FAFA, RV, HJTH and WFG conceived the study. FAFA and WFG performed the samplings. FAFA performed the histology and SEM observations. All authors contributed to the interpretation of the material, the writing of the manuscript, and its revision, and approved its final version. All the authors agree to be accountable for the content.
Conflict of interest
The authors declare that they have no conflict of interest.
Laboratory protocols and experimental conditions were in line with current international standards for cephalopod care and welfare reviewed by Fiorito et al. (2015).
About this article
Cite this article
Fernández-Álvarez, F.Á., Villanueva, R., Hoving, H.T. et al. The journey of squid sperm. Rev Fish Biol Fisheries 28, 191–199 (2018). https://doi.org/10.1007/s11160-017-9498-6
- Dosidicus gigas
- Sexual selection
- Sperm storage organs